Self Help Manual Of 1 Story Buildings

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MICROFICHE
REFERENCE
LIBRARY
A project

of Volunteers

in Asia

Self-Heln
Construction
of l-Storv
Peace Corps ATFD Manual M-6
by:

Peter

Buildins

Gallant

Published by:
Peace Corps
Information
Collection
and Exchange
806 Connecticut
Avenue, NW
Washington, DC 20525 USA
Available
from:
Peace Corps
Information
Collection
and Exchange
806 Connecticut
Avenue, NW
Washington,
DC 20525 USA
Reproduction
of this microfiche
document in any
form is subject
to the same restrictions
as those
of the original
document.

APPROPRIATE
TECHNObOGlES
FORDEVELOPMENT

of l-Slow Builtlimgs

S
INFORMATION COLLECTION & EXCHANGE
MANUAL

NO. M-6

INFORMATION COLLECTION AND EXCHANGE

Information
Collection
and Exchange
(ICE) was
Peace Corps'
established
so that the strategies
and technologies
developed
by Peace Corps Volunteers
in their
field
work could be made
available
to the wide range of development
workers
who might
find
them useful.
Training
guides,
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lesson plans,
manuals and other Peace Corps-generated
materials
developed
in the field
are collected
and reviewed:
some of these materials
are reprinted;
others
provide
an important
source of
field-based
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for the production
of manuals or for
research
in particular
program areas.
Materials
that you
submit to the Information
Collection
and Exchange thus become
part of the Peace Corps'
larger
contribution
to 'development.
A listing
cations

of all Information
available
through:

Collection

and Exchange

publi-

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Information
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and Exchange
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and Training
Coordination
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Ave.,
N.W.
Washington,
D.C.
20525
ICE Reprints,
Manuals,
and Resource Packets
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On a limited
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nations.
Others who may be interested
in obtaining
these
materials
may purchase
them through
National
Technical
Information
Service,
5285 Port Royal Road, Springfield,
Virginia
22161, and a few selections
are available
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Volunteers
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Maryland
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Add your experience
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send
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SELF-HELP CONSTRUCTION
OF l-STORY

Written
Peter

BUILDINGS

by
Gallant

illustrated
Nancy

edited

by
Bergau

Jim Seaton
Peter Hunt

Information

Peace Corps
Collection
and Exchange
Manual M 6

Special
Printing
for AID Resources
December,
1980

Self-Help Cons&.&ion
of I-Story Buildings
is the sixth
in a series
of publications
being prepared
by the United
States
Peace Corps.
These publications
combine the practical
field
experience
and
technical
expertise
of Peace Corps volunteers
in areas in which
development
workers
have special
difficulties
finding
useful
resource
materials.
PEACE

CORPS

Since 1961 Peace Corps Volunteers
have worked at the grass roots
level
in countries
around the world
in program areas such as
Before beginning
public
health,
and education.
agriculture,
Volunteers
are given training
in
their
two-year
assignments,
This training
cross-cultural,
technical,
and language
skills.
helps them to live
and work closely
with the people of their
development
It helps them, too, to approach
host countries.
problems
with new ideas that make use of locally
available
resources
and are appropriate
to the local
cultures.
Recently
Peace Corps established
an Information
Collection
&
Exchange so that these ideas developed
during
service
in the
field
could be made available
to the wide range of development
Materials
from the field
workers
who might find them useful.
are now being collected,
reviewed,
and classified
in the
The most useful
Information
Collection
& Exchange system.
The Information
Collection
& Exchange
materials
will
be shared.
provides
an important
source of field-based
research
materials
for the production
of how-to manuals such as SeZf-Help Constmction
of I-Story Buildings.
THE

AUTHORS

Pete Gallant
served as a Peace Corps Volunteer
in Liberia
for
three years.
During that time he worked on and supervised
a
variety
of projects
involving
the construction
of l-story
schools,
roads,
Mr, GaLlant-holds
a Bachelor
and bridges
in rural
areas.
of Arts degree in Political
Science
from St. Joseph College;
he
is now working
with the U.S. Department
of State.
(iii)

Peter Hunt workes for several
years in the audio-visual
and
training
departments
of Save the Children
Federation
where he
worked on materials
to help field
workers
promote cornmunityHe is now a free-lance
video
directed
construction
projects.
and print-based
training
materials
producer
and develops
videofor national
and international
organizations.
Seaton is Co-Director
of Communications
Development
Service
organization
that provides
field
training
(CDS), an independent
He specializes
in designing
materials
for development
workers.
and informal
educationalexperi.?nces
that help community
members
focus on their
own knowledge,
experience,
and human resources
-Mr. Seaton is currently
as the basis for self-development.
developing
training
workshops
in nutrition
planning
for several
countries
to help government
staff
respond effectively
to
community
initiatives
in integrated
rural
development.

Jim

the graphic
artist
for this manual,
served with the
Nancy Bergau,
Peace Corps as a graphic
design consultant
to the National
Broadcast
Training
Centre and TV Pendidikan
(Educational
TV), both
Before joining
Communications
Development
Service
in Malaysia.
she also worked as art director
for a
to work on this manual,
multi-media
public
health
education
program.
Ms. Bergau has
extensive
professional
experience
with the full
range of graphics
Her illustrations
proved invaluable
and audio-visual
production.
in shaping
the manual's
text and in making the more complex
technical
details
easier
to explain.

Many thanks
preparation

are due here to a number
of this manual:

Santa Cruz
Henry Baker, Director,
Recreation,
Santa Cruz, California.

of people

City

who aided

Department

of Parks

Program Director,
Rice
Steve Bender, Consultant.
Center for Community Design and Research,
Houston,
Tom Callaway,
Director,
Office
of International
Development,
Washington,

Division
Affairs,
D.C.

Earl Kessler,
Self-Help
Cooperative
Housing.

Construction

Special

are due to:

notes

of thanks

of Technology
Department
of
Advisor,

the

University
Texas.

and Documentation,
Housing and Urban
Foundation

for

Brenda Gates, for her continued
support
as Project
Director
the Peace Corps Program and Training
Journal
Manual Series.
Karen Seaton,
Communications
work andproduction
assistance

Development
with this
(iv)

and

Service,
manual.

for

her

of
lay-out

Please
a reply
form has been provided
here.
For your convenience,
send it in and let us know how this manual has helped or can be
If the reply
form is missing
from your copy
made more helpful.
of the manual,
just put your comments,
suggestions,
descriptions
on a piece of paper and send them to:
of problems,
etc.,
SELF-HELP CONSTRUCTION
Peace Corps
Information
Collection
& Exchange
806 Connecticut
Avenue, N.W.
Washington,
D.C. 20525
U.S.A.

PLEASE RETURN THIS FORM
because Peace Corps
NOTE TO USER: This manual was published
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In order to provide
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form and return
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SELF-HELP CONSTRUCTION
Peace Corps
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Collection
& Exchange
806 Connecticut
Avenue, N.W.
Washington,
D.C. 20525
U.S.A.
WHEN WE RECEIVE THIS FORM, WE WILL AUTOMATICALLY PLACE YOUR NAME ON
A MAILING LIST SO THAT YOU WILL RECEIVE:
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w'nich

may be of

the

manual

interest

as they
to

you.

If you have questions
on the material
presented
in the manual,
or if
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implementing
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offered
here,
Use additional
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have to in order to be as specific
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we will
try to provide,
or direct
you to, an
Wherever possible,
answer.
*

Date
Your Company or
Agency, if any

Your Name
Your

Address

How did you find 0u.t about
of I-Story BuiZdings manual?

the Peace Corps SeZf-HeZp Construction
How did you get your copy?

(vii)

manual

have

Which parts of the
useful?
Why?

Did you find the manual
complete
or incomplete?

How has this manual helped
apply the information?

Can you recommend additional
methods or equipment
which you
If
feel'should
be included
in a new edition
of the manual?
please include
the information
you know of such methods,
etc.,
here.

What were your successes
using the manual or implementing
Please describe
of the ideas or procedures?
Problems?
completely.

Do you have other

easy

you found

read,

your

work?

most

too

useful?

Least

simple

or complex,

What have you done to

any

recommendations?

Privacy Act Notice:
Furnishing
the information
requested herein is
completely
voluntary.
It is requested
under authorities
contained
in
the Peace Corps Act (22USC 2501 et seq.).
The only uses which will be
made of this information
are as follows:
1) For management purposes
involving
the format of future issues of this publication;
2) For incorporation
in a mailing list
for this and other similar
publications.

TABLE

OF CONYENTS
Page

About

This

. . . . . . . . . . . . . . . . . . . . . . . ..“.................

Manual

ReplyForm

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..~~...........~..vii
. . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . ..1

INTRODUCTION

A Note on the Development
Projects.......................
How To Use This
What This
1

BASIC
Site

iii

and Construction
. . . . . . . . . . . .. . . .. . . . . . . . . .3

Manual................................,....5

Manual

PLANNING
and

Process

Will
AND

Talk

About . . . . . . . . . . . . . . . . . . . ...*.*..

DESIGN

. . . . . . . . . . . . . . . . . . . . . . . . . . . -11

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Position

How Big Should the Site Be?..........................1
and How Private
Should the Site Be?..1
How Accessible,
What Kind of Soil Should the Site Be On?.............1
How Well is the Site Drained?........................1
How Should the Building
Be Placed on Its Site?.......2
Summary of Factors
Affecting
Site Selection..........2

Size,

Shape,

and

Floor

Plan

Materials

Rammed Earth

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...*.*

(Mud, Pise)
(ix)

4
6
8
9
0
1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

"..School s ..............................................
Clinics
..............................................
Homes ................................................
What Size Will Each Room Be?......................3
Using Measuring
Units to Help the Family Plan
Its Own Floor Plan ...............................
Helping
the Family
Draw Its Own Floor Plan........4
Drawing the Floor Plan of A House.................4
In All Buildings........4
Doors, Windows, and Ceilings
Where Will
Inside
Doors Be Placed?................4
How High Will the Ceiling
Be?.....................5
Where Will Windows and Outside
Doors Be Placed?
How Will They Be Designed,
and What Size Will
They Be?. ........................................
Windows in a Tropical
Climate.....................5
Protecting
the Inside
of the Building
From Rain
and Insects ......................................
Taking Advantage
of Any Breeze....................5
Windows in A Desert-Like
Climate..................6
Exterior
Doors ....................................
Construction

and Adobe

Bricks............67

22
25
27
0
31
1
2
8
8
1
52
3
56
8
2
65
66

Page
Wood ..................................................
Bamboo ................................................
Stone/Rock ............................................
Cement and Materials
Made With Cement.................7
Mortars...............................................~
...............................................
Concrete
Reinforced
Concrete...................................7
Blocks ................................................
Concrete
Blocks.......................................7
Sand-Cement Blocks
(Sandcrete)........................
Stabilized
Earth Blocks...............................7
Summary ...............................................
2

DETAiLED

PLANNING

Planning

FOR

Foundations

CONSTRUCTION..

Planning

Walls,

83
84
For

and

Roofs

Doors

......................

DIRECTIONS

Setting

FOR

CONSTRUCTION

Out iLaying

Out).

Marking

Batter

.........................

................................

..........................................
the Foundation
Outline.......................12
Boards ........................................

Orientation

(x)

92
93
94
5
96
101

..........................................

Roof Styles
and Their Functions......................l-...............................
Roof Materials
.. ......
Construction
Details
For Roofs.......................10
3

......................................

Windows,

Wall Height
and Length ................................
Wall Thickness ........................................
Placement
of Doors and Windows........................9
Construction
Details
for Doors, Windows and Interior
Walls ................................................
Planning

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 2

PlanningFOoors...........................................9

of Floors.

2
74
5
5
6
76

. . . . . . . . . . . . . . -79

Footings ..............................................
Foundation
Walls ......................................
Deciding
Upon the Materials
and Dimensions
..........................................
Foundations
Drawing Final
Foundation
Plans........................8

Types

69
69
70
0

t
7
115
,116
119
0
123

Page
Construction

of Foundation

. . . . . . . . . . . . . . . . . . . . 127

Footings

Digging
the Foundation
Trench........................12
Formwork For Footings................................12
Making the Concrete
For Foundation
Footings .........
Pouring
the Concrete
For Foundation
Footings.........13
Curing the Concrete
For Foundation
Footings..........13
Reinforced
Footings..................................13
Construction

of Foundation

Walls

Floors

of Walk,

Roofs

8
140
0
0
1
5
148
1
1

153
154

Windows,

and

Doors

.............

Block and Brick Walls ................................
Making the Blocks or Bricks.......................15
Blocks With Cement Content.....................15
Adobe Bricks...................................15
Laying Blocks and Bricks ..........................
Framing Windows and Doors.........................16
Roof Preparation..................................16
Rammed Earth Walls...................................16
Earth Mixture .....................................
Forms .............................................
Procedure.........................................l7
Framing Windows and Doors.........................17
Roof Preparation.
.................................
Construction

5
6
7

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Earth Floors .........................................
Concrete
Floors ......................................
Construction

.I30

. . . . . . . . . . . . . . . . . . . . . . . ,138

Concrete
Foundation
Walls............................13
Block Foundation
Walls ...............................
Making Blocks.....................................14
Making Concrete
Blocks.........................14
Making Sand-Cement Blocks......................14
Kaking Stabilized
Earth Blocks.................14
Laying Blocks .....................................
Finishing
the Mortar..............................15
Rock Foundation
Walls................................15
Construction

7
9

,157

157
7
7
7
160
4
6
9
169
170
0
1
172

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

Flat Roofs ...........................................
Shed Roofs ...........................................
Gable Roofs..........................................l7

(xi)

172
173
6

Page
4

CONSTRUCTION

WITH

181

..........................

BAMBOO

183

....................................

Bamboo For Foundations
Bamboo For Frames.

........................................

183

Bamboo For Floors.

........................................

185
186

Bamboo For Walls ..........................................

Bamboa For

Roofs..........................................18

Bamboo Reinforcement
Preservation
5

Pit.

of Concrete..........................18

8
... """18 8
..18 9

...............................................
of Latrines

190

......................................
...

................................................

"""19 1

Base ......................................................

192

Floor .....................................................

192

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

Shelter....
6

of Bamboo. .............................

LATRINES

Location

187

and Windows ..............................

Bamboo For Doors

CONSTRUCTION

llh EARTHQUAKE

Selection

and Preparation

Selection

Reinforcement
APPENDICES

Building

the

Materials

of Buildings

195

.................

AREAS

196

Site .....................

198

...........................

198

................................

201

. . . . . . . . . . . . . . . . ..“....““.“.““.“.““......“..“....

Calculations
Support
2. Step-By-Step

to Check Whether
a Building............
Directions

3. Estimating

the

Amount

4. Estimating

Materials

Site
will
a Proposed
. . . . . . . . . . . . . . . . . . . . . . . 202

For Drawing
of

Concrete

Needed
(xii)

Foundation
Needed

To Build

Plans...218

For a Floor...215

Walls.............217

Page
r; Reference
_.
6. Metric
U.S.
7. Sources
8.

Tables

Measurements

Concrete
Used in

Construction.....,........221
This

Manual

and Their

Equivalents.........................,............225
of Further

"Human Measuring
Floor

for

Information..........................226
Pieces"

For

Designing

Plan............................................231

(xiii)

Room Size

and

INTRODUCTION

This manual has been designed
to
help field
workers
with
little
or
no construction
experience
assist
a community
or family
to
*plan
and ,&sign
a l-story
community
building
(such as a
school
or health
clinic)
or home
that
fits
their
present
and
future
needs,
*assess
the
advantages
construction

advantages
of locally
materials,

-draw and understand
construction
plans:
.successfully
according

or disavailable
their
and

own

complete
construction
their
own plans.

FLOOR PLAN: VIEW OF A BUILDING
ABOVE

FROM

SIDE VIEW OF THE SAME BUILDING

The aim
1)

present

construction

process

three

basic

steps:

exploring
the needs of the people
who will
use a
first,
that
will
fill
as
building
and arriving
at a basic design
the basic
design
includes
many of those needs as possible;
decisions
about
the number and size of rooms,
the arrangethe major
construction
materials
that
ment of the rooms,
and the choice
of a site
for the building;
will
be usedl

2) second,
for each
roof;
3)

the

third,

written
construction
from the foundation

working
out a detailed,
part
of the structure,

actually

constructing

the

building

according

plan
to the
to

plan.

the manual
focuses
on basic
principles
In its
technical
sections,
of construction
with
materials
that
are low-cost,
available
in many
In any given
locale
or
and easy to work with.
parts
of the world,
different
materials
(or combinations
of materials)
will
be
climate,
But understanding
the construction
available--or
suitable.
principles
covered
here should
help the field
worker
work with
self-help
groups
to adapt
the specific
step-by-step
suggestions
to
whatever
materials
are available
to them.
No book could
hope to cover all design
and construction
problems
This manual presents
some of the most widely
used
or situations.
But in many cases,
field
innovations
in local
materials
and design.
workers
and communities
will
need to adapt these
ideas
tc conditions
The Peace Corps Information
Collection
&
at the project
site.
Exchange
hopes to incorporate
such local
adaptations
in future
Any comments,
suggestions,
or new ideas
supplements
to this
manual,.
are most welcome.
Please
send information
about your construction
project's
experience
to the address
on page (v).
One final
note:
the essentials
of the construction
process
are well
But the
within
the understanding
and skills
of community
groups.
field
worker
should
always
have one or more advisers
in mind who
In any
can be contacted
if problems
arise
during
construction.
projec-t,
no matter
how simple,
unforeseen
difficulties
or special
conditions
may pose problems
that
this
manual does not cover.
We
especially
during
the planning
have tried
to indicate
those
areas,
of a construction
project,
in which
assistance
from someone
experienced
in local
construction
problems
may be needed.
In
addition,
the bibliography
at the end of the manual
lists
other
valuable
sources
of more detailed
information
in Appendix
7.

NOTE

ON THE

DEVELOPMENT

PROCESS

AND

CONSTRUCTION

Few things
can inspire
a community
or family
more than seeing
and using
a building
that they have built
together.
In fact,
getting
a community
to cooperate
on a simple
construction
project
is one of the best ways to help them start
tackling
their
difficult
development
problems.
But not all
construction
projects
are effective.
In thousands
of
communities
all over the world,
schoolsl
clinics,
and homes have
been built
for people
and thenlzever
used, because
the design
of
the building
was unacceptable
to the people,
because
the community
could
not afford
to operate
it and felt
no sense of ownership,.
or
because
the building
didn't
fit
the community's
priorities.
When thinking
about
a construction
project,
therefore,
the field
he/she
hopes
worker
should
remember
that
the imediake improvements
will
result
from a new building
are less
important
than the community's
participation
in planning,
budgeting,
constructing,
and then using
a new building
itself.
The experience
of working
together
on a
project
can lead to increased
interest
and confidence
in further
community-managed
development
efforts.
But simply
watching
while
a building
is planned
and built
by others
can seriously
hurt
community
confidence
and provoke
hostility
to development
efforts.
The community
or family
must be (and must recognize
themselves
key actors
in all
stages
of a construction
project.
But the
worker
still
has a crucial
role
to play in the process.
The
worker
can function:
1)

as an initiator
of the project,a
non-formal
educator,
and a
catalyst
for decision-makinq.
Where traditional
approaches
or
solutions
are not serving
community
members well
enough,
the field
worker
can help them
explore
and define
their
own
needs/solutions
from a new
problem-solving
view-point.
There are organizations
in
almost
all countries
that
provide
information
and
training
in techniques
that
promote
this
exploration
process.

247-811,

0 - 77 - 2

as)
field
field

the

Once a community
has decided
to build
as a planning
assistant.
the field
worker
can provide
valuable
a home, school,
or &lxic,
information
and assistance
to help them design
the building,
and organize
the construction
purchase
and assemble
materials,
to provide
basic
technical
This manual is designed
process.
information
the field
worker
needs to help a community.

Community
groups
have limited
access
fund-raiser.
3) as a project
The field
worker
to the funds needed for small
local
projects.
generally
has much greater
knowledge
of, and contact
with,
and international
agencies
that
could
government,
private,
The Information
Collection
and
support
a community
project.
Exchange
publishes
a manual, Recources for Development Agents, that
may be useful
for field
workers
trying
to get technical
or
The manual talks
about analyzing
resource
financial
help.
needs and gives
names and addresses
of organizations
that
For a copy,
write
to:
provide
those resources.
Peace Corps Information
Collection
& Exchange
806 Connecticut
Avenue,
N. W.
D. C, 20525
Washington,
U. S. A.
Peace Corps Partnership
Program
can be a source
of
In addition,
funds to support
small
community
construction
projects.
Grants
of
$1,000
to $5,000
are made to communities
that
have initiated
plan to use volunteer
labor,
and donate
their
own project,
For information'*and
application
forms,
25% of all materials.
Peace Corps Partnership
Program,
at the
write
to Director,
address
above.
SUCCESS OR FAILURE?
Once the decision
to
concern
should
be to
succeed.
Success

depends

build
has been made, the field
workerls
ensure
that
the community's
self-help

on several

main
efforts

factors:

* Those who will
ultimately
use the building
should
be actively
involved
inevery
stage of the project---from
conception
to
planning
to construction:
their
needs,
desires,
and budgetary
restraints
should
be decisive
in all
planning
issues;
and the
The
project
must depend on their
desire
to pursue
it.
field
worker
should
never be the actual
leader
of the
He/she
should
provide
assistance,
not direction.
project.
* The building
plans
should
be simple,
and affordable.
far as possible,
the construction
materials
should
available.

As
be locally

* The completed
building
must be useful:
it should
have
adequate
space for its intended
use and it must be comfortable,
Space for future
additions
or
healthful,
and attractive.
needs should
be planned
for.

How

to Use

This

Manual

DISCUSSION
this
manual presents
information
that
For the most part,
anyone planning
a simple
construction
project
needs to have.
By reading
each section
thoroughly
in sequence,
field
workers
can prepare
themselves
to assist
community
groups
that
n.=ed
technical
assistance.
The sections
can also be referred
to
individually
at any time specific
information
is needed during
construction.
ILLUSTRATIONS
There are illustrations
the process
easier
to
using
these
illustrations
these
groups
understand
PLANNING

throughout
the book designed
to make
visualize.
Field
workers
will
find
that
with
the community/family
will
help
the field
workers'
suggestions.

EXERCISES

In Section
3: Basic Planning
and Design,
there
are suggested
exercises
with
paper cut-outs
that
a family
or community
group
can work on together
i.. order
to design
the size
of each room
they need,
and the floor-plan
(the arrangement
of the rooms)
of
the building.
These are most effective
when the field
worker
is present
to help the group explore
their
needs thoroughly
and
to help them prepare
the cut-outs.

What
Basic

This

Manual

Planning

Will
and

* will

be built
fill

chance of
designed
with

* is designed
abandoning
space will
the present

success,
any construction
proto ensure
that
the completed

the

budget

the

present

and

resources

needs

available;

those

who will

use

and placed
with
future
needs in mind without
the original
structure
(for
example,
if more
be needed two years
from now, can it be added
site?).

CAN THE PROJECT BE BUILT
Five things
construction

About

Design

To have a reasonable
ject
must be carefully
building:
* can

Talk

it;

WITH THE BUDGET AND RESOURCES AVAILABLE?

affect
a self-help
project:
availability
0 money
l
time
l
labor
(for
l
organization
l

gro_upls
of

ability

construction

complete

materials
and maintenance)

Availability
of Construction
Materials.
There are many different
construction
materials
available.
Denending
on local
conditions
such as
climate
and supply,
each one is-suitable
for different
of a building.
Each has advantages
and disadvantages
in terms
suitability,
cost,
time,
labor,
and durability.
A family
or
community
should
understand
the basic
characteristics
of all
available
materials
in order
to make the best possible
choices
fill
their
needs.

parts
of
to

Money is needed in construction
projects
to buy and transport
any
materials
that
are not available
near the construction
site.
costs
can be significantly
reduced
by using
locally
available
materials.
In most areas,
almost
the entire
building
can be built
from these
supplies.
However,
care must be taken
to choose
materials
that
are
durable
and safe.
Materials
fcr some parts
of the building,
especially
the foundation,
may be worth
purchasing,
even if
financing
is difficult.
Time.
Different
construction
time to prepare
and assemble.
seasons.
Thus the choice
of
schedule
of work,
all
depend
construction.

materials
Some can
materials,
on how much

require
different
amounts
only be used in certain
building
design,
and
time is available
for

7
Different
materials
require
very different
amounts 'and kinds
Labor.
certain
roof
designs
Some parts
of a structure-especially
of work.
--require
many more people
than others,
or people
with
different
who can work on a project,
their
skills.
So, the number of people
level
of skill,
and the time they can devote
to the project
must
be considered
while
planning
construction.
t building
has many different
parts,
%%%%%iat~~~~
%o~~~~$~s,
doors,
windows,
and roof.
These
must often
be built
in a certain
order
(for example,
the walls
usually
can't
be built
before
the foundation).
In addition,
each
part may be made from several
materials
that
must be put together
carefully
and in a precise
order.
For work to go smoothly,
the
builders
must be able to organize
the project:
to estimate
in
advance what materials
will
be needed,
how much of each will
be
needed,
and to bring
the correct
supplies
to the site
at the right
time.
Many projects
fail
because
a vital
material
is not ordered
in time and all work must stop until
it arrives--sometimes
too long
a wait
for work to begin
again.
WILL THE BUILDING
USE IT?

FILL

MORE OF THE PRESENT NEEDS OF THOSE WHO WILL

All build2ngs
should
be durable,
addition,
other
considerations
or family
designing
a building.

healthful,
and comfortable.
In
should
be kept in mind by a community

A community
planning
a clinic
or school
must consider
many different
needs.
For example,
a clinic
would have to have space for treating
patients,
for people
to wait before
they are treated,
and perhaps
space for one or more people
to stay overnight
while
recuperating.
These would be the primary
needs.
However,
the community
might
also
desire
to use the clinic
for educational
purposes:
health
education,
for example,
or nutrition
classes.
The most effective
design
would
depend on aZZthe planned
uses of the building.
The
A family
needs to plan enough space for all
family
members.
family
must decide
how many rooms they need, what kinds
(dining,
sleeping,
Other
needs may include
ease of
etc,)
and what size.
movement,
storage
space,
privacy,
etc.
IS THE BUILDING
Present

needs

DESIGNED WITH FUTURE NEEDS IN MIND?
may change

soon:

there
may be many more
years
fromnow;
or the
meetings
in the school

a doctor
may move into
living
space near the

the community
clinic;

a family

need

may grow

and

students
in the school
3
community
may start
holding
next year;

room.

and need

8
Future
needs like
these
can be difficult
to fill
if the building
is
constructed
next to something
(like
a river
or road)
that will
block
or if it is designed
in a way that
makes
future
construction;
The
easiest
way
to
ensure
that
a
building
will
additions
impossible.
be useful
throughout
its
lifetime
is to anticipate
future
needs and
plan so that
they can be filled
easily
by adding
to the present
design
whenever
they arise.

SITE
In

SELECTION

addition

which direction

Four factors
position:

AND POSITION

a building's
design,
it faces
(the.position)
must be considered
in

where it's
located
are crucial
to
choosing
the best

Will
a school,
,for example,
*location:
all
students
to reach?
Can construction
to the site
easily?
*terrain:
drained
affect

Is the land hilly
or
subject-to
or marshy?
building
design,
safety,

*Size
of
Is there

Nanning

Buildings
l

footing

have

and

4 basic

Directions

parts:

and foundation

0 floor
l

walls,

roof

doors,

and windows

and

easy for
be brought

or soft?
wellAll these
factors

land for the building?
to the building?

prevailing
*Climate:
The temperature,
affect
the comfort
and healthfulness
posit&n
of a building
is crucial
in
environment
inside
the building.

Detailed

be relatively
materials

flat?
hard
earthquake?
and comfort:

Is there
enough
future
additions

the plot:
room for

(the site)
its
success.
site
and

winds,
and rainfall
all
And the
of a building.
helping
to control
the

Qor Construction

the information
needed to draw
Section
2 of the manual contains
plans
for each of these parts.
Section
3 contains
step-by-step
guides
for the actual
construction:
that
is, how to work from
written
plans
to complete
a structure
that
will
last
a long time
and require
a minimum of maintenance.
FOUNDATIONS
The foundation
of a building
provides
a level
base for the
structure
to stand on.
It must
be strong
enough for the building
that
sits
on it;
it must be level
and plumb (straight
up and down);
and it must be secure
from
damage by water,
frost,
settling
earth,
and earthquakes.
FLOORS
Floors
provide
a secure,
level,
and comfortable
surface
for
everything
inside
a building.
They must be far enough above
,ground
level
to remain
dry,
easy
to keep clean,
non-slippery,
and
level
(so that
objects
do not
roll
or slide).
WALLS,

DOORS, AND WINDOWS

Walls provide
privacy
and shelter
from the elements.
They also
hold up the roof.
They must be thick
enough to protect
the
inside
from heat or cold,
strong
enough to support
the roof
and
withstand
wind pressure,
and high enough so that
people
can stand
comfortably
without
hitting
their
heads on the ceiling.
Doors and windows
provide
light
and ventilation.
In addition,
doors
(or doorways)
allow
people
to move in and out of the
building
and between
rooms.
They must be designed
to allow
only as much light,
air,
cold,
and heat as desired
into
the
building;
at the same time,
they must keep insects,
dirt,
and rain
outside
and provide
privacy
when closed.
ROOF
The roof protects
a building
from rain,
snow, wind,
cold or heat,
and insects.
It must be designed
to withstand
wind pressure,
and
the weight
of anything
that
might fall
on it.
In addition,
care
must be taken
to ensure
that
community
members will
be able to
build
the roof
(the parts
cannot
be too heavy to lift).

Latrines
Latrines
are important
to good
heal,th
because
they can
eliminate
diseases
spread
through
human excrement.
They should
be included
in
the planning
of any public
building
or home.
Special
rules
apply
to their
location,
positian,
and
See Section
5,
construction.
page 189.

Earthquakes
Earthquakes
place
severe
stresses
on' buildings.
But there
are many
methods
of construction,
principles
of design,
and materials
that
can help a building
withstand
tremors--at
least
long enough to
allow
occupants
to escape
safely.
Most of these
earthquakeresistant
techniques
cost nothing
at all,
or are very inexpensive.
Builders
in earthquake
zones can and should
use these
techniques
even when their
budget
is limited.
See Section
6, page 195.

BASIC

WANNING

AND

DESIGN

Before
construction
can begin-or detailed
need to consider
can be drawn-- the builders
and design
questions:

SITE

will

the

SHAPE,

will

the

What

How will
each room
in relation
to the
(that
is, what will
plan be)?

the

each

family

room be?
be placed
others
the floor

What shape will
the building
be?
Round?
Rectangular?
Some other
shape?

. How high
l

AND FLOOR PLANS

0 HOW many rooms will
or comraunity
need?
size

building

on?

o Where on this
site
building
be placed?

for construction
basic
planning

AND POSITION

o What land
constructed

SIZE,

plans
three

Where
be?

will

the
doors

ceiling

be?

and windows

-1.
I..
*:
“

2;
:

CONSTRUCTION MATERIALS
. What
floor

will
the foundation
be made of?

and

e What will
and doors

the walls,
windows,
be made of?

o What
of?

the

will

roof

be made

There are a number of simple
guidelines
that
anyone planning
a
But it is
building
can follow
in answering
these
questions.
important
to treat
them as guidelines
and not as hard and fast
Those who will
use
There are rarely
any "right"
answers.
rules.
the building
must be prepared
to find
compromises
between
their
needs and budget
on the one hand,
and the limitations
of local
and construction
materials
on the other.
climate,
soil,
geology,
This section
of the manual is designed
to help the field
worker
and community
member(s)
work together
step-by-step
to answer
the
three
basic
planning
questions
above for schools,
health
clinics,
and homes.
By following
the process
sugg?si:ed,
the builder
will
end up with
an accurate
picture
of what his or her building
will
be like.

SITE AND

POSITION

Families
and communities
need to
decide
carefully
where they will
build.
They need to know their
building's:
.SITZ
The plot
of land the
building
will
be on; where
will
the land be?
what will
its boundaries
be? how big
will
it be?
,POSITION
The exact
position
of
the building
on the site;
which
way will
the building
face? how
far will
it be from each of
the site's
boundaries?

.-.-18.11
I
i

Taken together,
site
and position
are just
as important
as, if not
more important
than,
how well
the
building
is constructed.
They
can determine
a building's
safety,
usefulness,
and durability.
In addition,
a well-chosen
site
can significantly
cut the cost
of construction
and maintenance.
How

Sig ShouId

the

Sii

i
POSSIBL;v
I

r---7
HOUS: SITE

i
i

h ---II !!” 1

Be?

At the very least,
the site
must be
big enough for the building
being
planned
plus
at least
some room
around
the building
for the
storage
of construction
materials
during
the construction.
Generally,
about 2 meters
along
each side of the building
is
the minimum builders
will
need.
In urban areas,
extra
land may be
required
for health,
safety,
transportation,
or other
needs.
A major note of caution
here:
a site
can only be truly
adequate
if it
leaves
enough room for present
and
future
needs beyond the space
taken by the main building
being
planned.
These needs will
be
different
for different
types
of
buildings.

y-.rr.rr.-.-,

LATRINE

iFKiz~

i
i
I
i

.
STREAM
--

i
I

GARDEN

i
i
i
i
i
Ci

I-

Here are some of the things
planners
might want to leave space for:
Schools
- a shaded outside
area for
assemblies,
lunches,
outdoor
classes
- recreation
area for sports,
play
- future
classrooms
- other
additions
such as
offices,
library,
theatre,
school
garden
- compost
pile
- livestock/poultry
pens
at least
- two or more latrines
17 meters
from water
supply
- cistern/well
- lodging
for teachers
- storage
for school
and
maintenance
supplies
Health

.~.~.I.-.-.B.~.-.~.I.

I
’
I

GARDEN

I
.
I

---

I
I
FUTUIRE-EXPAN~ I ON
r
I

I.
I

UTURE MEETING ARE.A ’
I
I
I
DMS !
.
:
L ---0
I
LATRINESM
0
i

I*
I.
I

i .a.-.lr~I.-.II.I.-.-.-.
i

LATRINES

I, r--F;-&---l
!i

RECUPERATION 1
--Y-III--

H0m.es
-

outdoor
latrine
garden
livestock/poultry
additions
future
well

Y-I-----pens
to the

;
I

Clinics

- future
additions
for extra
reception
and treatment
rooms
- cooking
area for patients
who must stay in clinic
- latrines
- well
- lodging
for health
workers/
doctors
- separate
building
for
maternity
care and
recuperation

SMALL -CLIN I C

home

Many of these
needs may appear
farfetched
to the family
or community
plan their
building
when they first
However,
the field
worker
project.
should
urge them to allow
room for as much future.
expansion
as
It is always
easier
to add to a present
building
and
possible.
site
than to start
over again because
there
is no room at the first
site.

16
Even in cases where
gi3x al1
cr,.ough site
*
to their
site
might
In addition
to
consider
other
expansions:
. rivers,
. heavy

the actual
conditions

size of the
at the site

site,
that

afford
a large
what land next

planners
need to
might
block
future

streams
forest

. unsuitable
marsh)
.

the family
or community
cannot
fiitilre
needs,
theycm
consider
be obtained
for later
expansion.

or
land

roads,
markets,
buildings

bush
(such

existing

Whether
these
obstacles
are on the projected
site
itself,
the land next to it,
care should
be taken
that
they will
block
the builders'
present
or future
needs.

HowAccess

ible,

and

How

Private

Should

the Sit&

or
not

Be?

A building
can only be easy to build
and easy to use if the site
if it is conveniently
close
to other
people
is accessible;
that is,
and places
in the community
and if it can be approached
easily.
At the same time,
a building
use it if the site
provides
Privacy
can also be important
and smells
can cause serious
to a heavily
travelled
road.
Because
the
for privacy,

can only be comfortable
for those
who
enough privacy
to satisfy
their
needs.
for health:
for example,
dirt,
dust,
problems
if a building
is too close

need foraacessibility
planners
often
have

often
conflicts
with
the need
to compromise
between
them.

Unless
the materials
for
Access
for Construction.
construction
are available
on the site
itself,
some or all
of them will
have to be brought
to the site
in large
amounts.
Generally,
this
means the site
should
be near a road,
or in
an area where a road to the site
can be built.
-In addition,
there
must be space on the site
to store
materials
during
construction.
To serve its
purpose
well
a building
must
Access
for Use.
For
different
be easy for people
and supplies
to get to.
kinds
of buildings
different
considerations
should
be kept
in mind.
For example:
SchooZs should
be
- within
reasorlable
travel
distance
(by foot
and/
or vehicle);
- close
to clean water;
- close
to fuel
supplies
in cold climates;
CZinics

should
be
- centrally
located
so that
them easily;
- close
to clean water
and
- next to a roadway
suitable

the

community

can

reach

fuel
supplies;
for vehicles;

Homes should

be
close
to clean water
for cooking
close
to neighbors;
close
to fuel
supplies;
close
to the family's
fields
or
the family
earns income;
- close
to markets;
- close
to community
facilities.

Privacy,
should

and washing;
other

places

where

All building
sites
Health,
and Safety.
Comfort,
be:
- away from rivers
and streams
heavily
infested
with
or other
sources
of disease;
mosquitoes,
bush,
or jungle
(all
these
cut off
- away from forest,
breezes,
are dangerous
in case of fire,
and provide
homes for snakes,
rats,
ants,
and other
pests):
- away from major roads
and other
sources
of noise,
smells
(this
is especially
dust,
dirt,
distraction,
important
for schools
and clinics);
- away from flood-prone
areas;
- away from fault
lines
in earthquake
areas
(see section
on earthquake
areas,
page 195.

18
What

Kind

of Soil Should

the

Site

Be On?

Possibly
the most important
consideration
in choosing
any site
is
that
the soil
must be able to support
any building(s)
erected
can be built
on (or over),
but the nature
Almost
any ground
on it.
of the site
chosen will
affect
the simplicity
or complexity
of
the cost of construction
in labor
and money, and
the foundation,
the durability
of the building.
. Rocky soiZprovides
the strongest
s-upport
for a building,
usually
much more than is necessary
for a l-story
building.
But while
it is extremely
stable,
it can be very hard to
excavate.
l

Hard-packed cZayis
strong,

but

easy

generally
to work

the
with.

best

soil

for

l-story

buildings:

Sand a=pdgravezare

usually
acceptable
soils
for l-story
They can support
about half
as much weight
construction.
as clay,
but they are subject
to shifting
or
slipping,
especially
if the site
is-not
on level
ground.

Soft b2ack sod2, drained ma.rshZand, and %ade" earth CfZ22 thut has been
co22ected and packed) are satisfactory
soils
for construction.
buildings
constructed
on these
soils
should
be
However,
built
on concrete
foundations,
or on raised
platforms.
In addition,
buildings
on these
soft
soils
should
be made
-..v
--a. a.ULJ available.
with
the lightest
suitable
rn;rfar;-lBlack
topsoil
contains
decayed
organic
matter
that
makes
In areas where such soil
it soft,
especially
when moist.
goes more than 30-45 ems. deep,
it must be removed before
Otherwise
it will
almost
certainly
construction
can begin.
cracks
or collapse
shift
under the foundation
and lead to wall
of the building.

Each type of soil
has very definite
limits
to the weight
it will
l-story
buildings
will
be well
support.
Generally
speaking,
within
those
limits
except
in the case of buildings
with
rock
walls
on the weaker
soils.
When a tentative
site
has been selected,
double
check that
the soil
at .2he site
building
safely.
Quite
often
this
can
at similar
nearby
buildings
(2 or more years old) on the
If they
same kind
of soil.
show signs
of uneven settling
such as cracks
in the walls
or
foundations,
the side of the
new building
may have to be
dug out and filled
with
firmer
soil,
or another
site
may have
to be selected.

it's
a good idea to
will
support
the planned
be done simply
by looking

In cases where there
are no similar
buildings
nearby,
or no
an estimate
of the planned
building's
weight
similar
soils,
per square
meter
should
be made and compared
with
the weightDetailed
directions
for calculating
bearing
capacity
of the site.
plus a guide
to the weight-bearing
the weight
of a building,
capacity
of various
soils
will
be found
in Appendix
1.
Almost

as important
as the type of soil
at the site
is the
If the ground
at the site
contains
a
of the soil.
mixture
of different
soils,it
must be dug out and filled
in until
it is uniform
in order
to provide
a stable
support
for any building.

uniformity

If the ground
at the site
cannot
be made uniform,
or if the
weight
of the planned
building
will
be close
to the weight-bearing
it may be necessary
to use reinforced
capacity
of the site,
concrete
in the foundation.

How

We13 is the

Site

Drained?

In addition
to the weight
the site
can support,
builders
need
Water seepage
can
to consider
how well the land is drained.
destroy
even the strongest
foundation
if it is not controlled
or
planned
for.
Wet or damp floors
can make a building
uncomfortable
and unhealthful.
Whenever possible,
mmshZand or any ground
that
lies
underwater
for
extended
periods
of time should
be avoided
for construction
In some areas,
people
have developed
methods
for conpurposes.
struction
on stilts
because
they have no access
to dry land,
or
because
they depend on access
to the water
for economic
support.
Buildings
in these
areas
should
be made of light
materials
and
should
be replaced
often.

LOU-lying 2and, and land

that
may be exposed
to short-term
flooding
is also less than
desirable
for construction
purposes.
When there
is no
choice,
however,
this
kind
of
land can sometimes
be
improved
by digging
a trench
about
25 ems. wide and lo-15
ems. deep around
those
sides
of the building
site
that
won't
drain.
These trenches
should
lead far enough from
the planned
position
of
the building
to keep water
from rising
to the foundation
depth.

247-801

0 - 17 - 3

20
is more than 30-45 ems.
If the dark topsoil
in low-lying
areas
effort
to find
a different
site
should
IX made, since
deep I every
removing
this
topsoil
for a firm
foundation
will
be expensive
and
can make effective
drainage
much more difficult.
High, dry groundis
usually
the best
for building
sites
since
However,
not subject
to the ill-effects
of water
seepage.
Planners
need to avoid
or guard
against
can be too high.
dangers:
*if
the ground
is
a level
area for
expensive;

the excavation
also hilly,
the foundation
may be too

needed
difficult

it is
ground
these
to

produce
or

rapid
drainage
may cause
*if
there
are heavy rainfalls,
or
landslides
that
can cause a
ground
slippage,
erosion,
building
to collapse
or can bury it;
in most cases,
a retaining
wall
and carefully
planted
trees
can solve
these
problems,
but both alternatives
can be expensive;
*if
high
building
roof.
The ideal
site
,and sheltered

ground
is exposed
may be in danger

to
of

high winds
or storms,
the
collapse,
olr it may lose its

for any building
is on dry soil
against
gro*und slippage,
strong

safe
winds,

from
and

flooding
storms,

4
How

Should

the

After
selecting
site
the building
is chosen
should

Building

Be placed

On Its Site?

the builder
needs to decide
where on the
a site,
The position
that
or buildings
planned
will
be.
ideally:

l be far enough back from the site
boundaries
for privacy
and comfort
cleave
room for future
additions
*leave
sufficient
room for storage
of construction
materials
l allow
the windows
and outside
doors to face as close
to
north
and south
as prevailing
winds will
allow
(see the
section
on windows
and doors,
page 52)
*be as level
as possible
ebe as dry and strong
as possible
brush,
or jungle
area on the site
abe away from forest,
@conform
to all
local
legal
regulations.

Summary

of Factors

Affecting

The most
consider

important
factors
in choosing
a site
gwhether
the
the building;
*whether
prevent

soil

Site

Selection

community
for their
will

groups
building

support

the site
is drained
water
damage:

@whether
the site
their
immediate

is large
and future

and families
are:

the

weight

@whether
the
construction

site
is easily
accessible
and use of the building:

@whether
healthful.

site

the

well-enough
enough
needs;

comfortable,

safe,

should

to
accommodate
for
and

In most cases,
builders
have to compromise
between
these
concerns.
Choosing
the best site
among several
less-than-ideal
possibilities
It is always
best to get
is often
difficult
and complex.
Contractors,
whenever
there
is any doubt.
experienced
advice,
or architects
in the area can help make the options
engineers,
clear,
especially
in terms of cost and labor.

P
O?W F&zZ Gaxtim.
In many areas,
local
regulations
will
influence
what can be built;-where
it can be built,
and how it can be built.
Building
and zoning
codes,
permits,
licenses,
and accepted
practices
vary widely
from
country
to country
and locality
to locality.
To avoid wasted
or illegal
effort,
the field
worker
should
help family
or community
members learn
their
restrictions
and obligations
during
the basic
planning
and design
process.
on a
This should
always
be done before settling
definite
site
for construction.

222

SIZE,

SHAPE,

AND

FLOOR

PLAN

sohools
the smaller
a building,
the less it will
cost to build.
Generally,
So the first
aim of any community
group planning
a new building
If they
should
be to decide
what their
mintium space needs are.
it will
be easy to add room
can afford
more than the minimum,
before
construction
plans
are final.
Small community
schools
are generally
simple
to
plan a minimum of 1.3 square
meters
classrooms,

For example,
in a l-room
school
for 30 students
(the most that
should
be
planned
for in one class),
you would
need about
30 x 1.3

For
design.
per student.

indoor

ACHER
EE
(sl

= 39

square
meters
for seating.
Add to this
about 2 meters
in front
for a chalkboard
and teacher's
desk/table.
This
like:

what

could

look

Classrooms
for fewer
students
can be smaller
as long as there
is
about
1,s S~EYW meters per student
for seating
and about
2 meters
across
the front
for the teacher.
if the community
However,
can afford
it,
it is a good idea to build
every
classroom
at least
5 x 8 meters.
The extra
space will
come in handy for exhibits,
special
projects,
and extra
students
if class
size
increases.

end

more storage
and/or
of the school.

6
1
I--I I
I
i

office

space

STORAGE

required,

add

on the

OFFICE

PORCH

i
I
I
L--

If there
will
be more than 1
teacher,
the plans
should
include
one room for each teacher
and his/
The additional
her students.
classrooms
can be added as needed
next to the first.
If the community
plans
to use the
school
as a public
meeting
room,
thought
should
be given to making
the first
classroom
larger
than
needed to accommodate
large
adult
assembly
room
groups.
Or, a large
might
be built
specially
for the
purpose
and attached
to the class
for use as a theatre.
Many communities,
especially
tropics
will
want to plan
porch
for use in very hot

in the
a shaded
weather.

r-----7--y--7
I

I
I,

FUTURE
CLASSROOM

;

1
--em r --- -1
----

I----

FUTURE
LIBRARY,EXHIB/TS

I
I

IL------

Don't
school
apply

forget
to plan for latrines
and a water
supply
for special
grounds
(see section
on latrines
to the location
and number of latrines).

If needed or desired,
thought
lodging
for
a school
garden,
Here

one

possible

site

should
teachers,

plan

be given
to
and sports.

including

these

i.
Ii

TEACHERS ’
BEDROOMS

s
s
u
VI
.n

I
!

I
I.
(I

!
I

FUTURE ADDI’ TIDN i

L --

WELL

RECREATION

space

features:

LATRINES

---

on the
rules
that

-B-w--

i
I
i
I

eT”a

i
i
i
i

COMiOST I.
-e

GARDEN

!
I
I---;
L I V’ESTOCK i
!
!

for

Health

Clinks

planning
than schools
Health
clinics
usually
require
more advance
because
separate
rooms are
to fill
a community's
needs well,
needed for the reception
and treatment
of patients,
care of
patients
who must sleep
in the clinic,
and space for office
and
In addition,
latrines
should
be included
in the plans
supplies.
for any clinic
(see separate
section
on latrines
for detailed
planning).
LATRINE

4 m.

3 m.
This

is a floor
plan for a
health
station,
with
3 rooms and 2 inside
walls,
measuring
7 X 5 meters.
small

Ii
*m

OFFICE/
SUPPLIES
RECEPTION/
TREATMENT
,

I
PAT I ENT
BEDRSUM

A more complete
clinic
might be twice
the size,
7 X 10 meters.
To reduce
noise
that
may disturb
in-patients,
and to reduce
the
patient
rooms should
be as far as
possibility
of infection,
possible
from treatment
rooms.

3Ii
I
i
m

RECEPTION

PATIENT

BEDROOM:

TREATMENT

OFF I CE/SUPPL’I ES.

LATRINE

LATR I kr

A desirable
addition
to one of
these clinics
would be a midwife
station
in a separate
structure
on the same site.
Midwife
stations
permit
special
care for mothers
and babies
during
and after
delivery,
without
exposing
them to infection
from clinic
patients.
Here is
midwife

a possible
station.

plan

This

a SITEplan

for

TREATMENT

a complete

health

clinic.

LATR I NES

----

i
i

In normal
times,
housing
projects
are more difficult
to organize
But
than community
projects
such as schools
and health
clinics.
such as an earthquake
or flood,
many people
after
a disaster,
a time when they may be least
are in urgent
need of new homes ---at
able to afford
construction
or to think
carefully
about
their.new
As a result,
many agencies
providing
home's design
without
help.
disaster
relief
have tried
to design
and build
new homes for people
---only
to find
that
the new homes stand
empty‘because
people
don't
This problem
can be avoided
if field
workers
use the
like
them.
ideas
suggested
in this
section
to help
families
plan
their
own
homes.
As with
schools
and clinics,
the smaller
a house,
the less
it will
usually
cost to build.
Here
help
their
l

BATH I NG

are some guidelines
to
a family
decide
what
minimum needs are:
The plans
for a house
should
clearly
shah?
where each of the
family's
basic
activities
Even
will
take place.
the smallest
home must
have adequate
space,
either
inside
or outfor the family
to
side,
sleep,
cook,
eat,
and
move around
in comfort.

EAT I NG

the family
should
consider
including
space in
In addition,
Latrines
are especially
its
plans
for a latrine
and a shower.
They can be designed
important
for every
family's
health.
But there
are several
as part
of the main house itself.
advantages
to building
latrines
as separate
structures
on
an outdoor
latrine
For example,
the same plot
of land.
can be moved easily
when it fills
up.
Other
activities
laundry,
prayer,

a t:,A.ly
may wish
and private
space.

plan

space

for

include

a family
can save money by
. When cost
is a critical
problem,
using
rooms to serve
more than one purpose:
for example,
a single
room can provide
living
and eating
quarters
by day,
and sleeping
space by night.

28
The following
what kind of
build.

questionnaire
can be used to help
space they need and how many rooms

a family
determine
they need to

A.
1.

SLEEPING SPACE
How many people
will
sleep
in your
house?
2. Which people
will
share a bedroom with
each other?
(Write
their
names in the
blanks
for each roomi
Room #3
Room #2
Room #l

01 ’ I ’ ’

In the
number

circle
to the left,
of rooms needed for

B.
1.

DINING SPACE
How many people

will

eat

write
the
sleeping
area.

your

house?

2. Will
they eat inside
or outside?
Will
the
eating
space be attached
or unattached
to
the house?
(Check the correct
boxes)
3. Can one of the bedrooms
also be used for
dining
space?
(If yes, leave
the circle
to
the left
blank;
if no, write
in 1.)

C. LIVING/SOCIAL
SPACE
1. Do you need space inside
and/or
outside
for family
members to spend time
together
or for visitors?
2. If so, can this
living
space be the same
leave the
If yes,
as your dining
area?
box blank;
if no, write
the number of
inside/outside
rooms needed for living/
social
spaces
in the circle.
Check if
spaces will
be attached
or unattached.)
D. COOKING SPACE
1. Do you plan to cook inside
or outside
your house?
2. Do you want the cooking
space attached
to
the dining
area or unattached?
(Write
the
number of cooking
spaces needed
in the
circle
and check the correct
boxes.)

E. BATHjPERSONAL WASHING SPACE
1. How many rooms for personal
washing
do
you need?
2. Will
this
space be inside
or outside
the
house? Attached
to the house or not?

F.
1.
2.
3.
b

LAUNDRY SPACE
Do you need space in the house for doing
laundry?
If so, will
the laundry
space be inside
or outside
the house? Will
it be attached?
Can the laundry
space be in the same
area as the bath?
(If yes, write
"0" in
the circle;
if no, write
"1")
1

O”T”
O’“-”

G. PORCH/VERANDAH
1. Do you need a porch
outside.your
house?
If yes, write
"1" in the
If no, leave
the circle
blank.)

circle!

H. STORAGE SPACE
1. Do you need separate
room(s)
for storage?
Will
they be inside/outside,attached/
unattached?
Write
the number of rooms
-needed
in the circle
and check the correct
boxes.
I.
1.

OTHER SPACES NEEDED
Do you need separate
rooms for
activities
besides
those
listed
For example,
do you need separate
for prayer,
family
meetings,
or
needs?
If so, write
the number
needed and the purpose
for each

other
above?
space
other
of rooms
one:

Check over your answers
to these questions.
you've
listed
should
help you decide
exactly
kind of rooms/spaces
you need to plan.

The information
how many and what

WHAT SIZE

WILL

EACH ROOM BE?

Ta be useful
and comfortable,
a room must be large
enough and
properly
shaped
for its
function.
For example,
a bedroom
must
be long enough
for a person
to lie down in and wide enough
so he or she can get out of bed and in and out of the room
easily.
A latrine,
on the other
hand,only
needs to be large
enough for a person
to sit
or squat
(unless
people
also
plan
to dress or wash in the same area).
The best way to make sure that
a room will
be large
enough is
to decide
how large
it would have to be for the largest
adult
likely
to use or visit
the home.
Then the room will
be comfortable
for everyone.
[Note:
Often
the proper
size and shape of a room is determined
more by traditional
requirements
and social
patterns
than by
physical
comfort.
Field
workers
must be sensitive
to the
community's
needs and priorities
and should
explore
them
thoroughly
with
the family.]

Here

are

some guides

- Most

adults

for
will

a "human"
be less

than

measuing
2 meters

unit:
tall;

- An adult
usually
needs 2/3 meter
from side to side and
from front
to back in order
to move around;
and about
1 meter,
or nearly
half
his/her
height,to
sit
down.
2/3 m.

l+=-

1 m.

31
USING MEASURING UNITS

TO HELP THE FAMILY

PLAN ITS

OWN ROOM SIZES

A family's
interest
and confidence
in a building
project
will
be
much gre,ater
if they are able to envision
and plan their
home's
A first
and very important
way the field
rooms themselves.
worker
can help them do this
is to visit
other
homes in their
community
with
them and question
them carefully
about
their
Some questions
a family
might
want to ask include:
reactions.
. Do we want our rooms to be larger
or smaller
than these?
. Would we like
them to be the same or a different
shape?
a How do we feel
about
rooms with
more than one purpose
(for
example,
sleeping,
dining,
and living)?
in, or
0 Are the rooms we have seen easy to move around
difficult?
l
Is working
in the kitchen
or laundry
space easy,
or does
it take a lot of walking
back and forth?
Do family
members get in each other's
way when moving
from
l
Where and why?
room to room?
Once the family
is familiar
with
a number of different
possible
designs,
they will
need to put the actual
size and arrangement
of
rooms in their
new home on paper.
An easy way to help them get started
is to give the family
pieces
Using
12 cm. for
of paper
representing
the "human" measuring
unit.
1 adult
length
is the most convenient.scale
since. l/2
adult
is an
is 4 cm, The family
,even 6 cm. and l/3 adult
will
need pieces
for:
*

the length
and width
of
standing
or lying
down;

an adult

the length
sitting;

an adult

the space an adult
needs
to side in order
to walk

and width

from side
or work

Remember that
that
they can
needed.

any furniture
they have or special
space needs
in countries
with
cold
climates,
(for example,
space may be needed for chamberpots
in the
bedrooms
so people
don't
have to go out at
night).

the pieces
be used to

Extra
copies
NOTE:
community
group-are

must be proportional
to
get an accurate
picture

of the planning
pieces
for
Appendix
8.
provided
in

A family
can design
its
own
rooms by gathering
pieces
it
needs for any room and then
arranging
them into
a square
rectangle,
or circle.

For

example,

a bedroom
one child

a family
for a couple
would need:

planning
and

,, 2 pieces
of an adult
length
and width
for
the couple's
sleeping
l

1 piece
for the
area;

S-length
child's

. 1 piece
f-length
for an adult
to
. 1 strip
the width
adult
for clothing
storage:

area:

x $=-length
sleeping
x S-length
sit;
of an
or

. 2 strips
the width
of an
adult
for each parent
to
walk around
their
bed(s),
and to walk to the baby's
bed;
0 extra
pieces
for large
furniture
or other
needs.

one another
so
of the space

use

with

Once the
together
possible
experiment

the family
should
try to put them
pieces
are gathered,
so they form a room-shape.
There are many combinations
for any room, so people
should
be encouraged
to
with
AF. many arrangements
as possible.

ALTERNAT IVES

When all
the pieces
have been
placed
together,
a line
should
be drawn around
them.
-This
line
represents
the complete
room‘113
If the shape of the room is
irregular,
the field
worker
should
help the family
make adjustments
until
it
is a simple
shape.

FINAL

CHOICE

Space

can be added to complete
a square,
rectangle,
of the space in walking
areas can be carefully
up to l/3.

or circle,
reduced
by

Some

f ADULT

3 ADULT

+ ADULT

To find
of the
first
adult
of the

out what the dimensions
final
room should
be,
calculate
the number of
lengths
along the sides
room.

Then the family,
or
if necessary,
worker,
multiply
the number
lengths
by 2 meters.
The answer will
equal
dimension
of the wall

the

field
should
of adult
the actual
in meters.

EXAMPLE:Caihduttin
of Dimensions
of Rectangub
RoomAbove
width:
f
3
&
14

adult
adult
adult
adult

length
length
lerkjth
?engths

2 meters

= 3m

Len&+
1
2/3
l/3
2

adult
adult
adult
adult

length
length
length
lengths

x 2 meters

= 4m

RoomDGnensions: 3 meters x 4 meters

Here are some additional
measures
that
may be useful
what pieces
the family
must use in planning
kitchens
cooking
areas),
and dining
areas:

Work space in kitchens,
be about
l/2 adult
wide.
to reach across;
Space for fuel
in
by l/2 adult
wide:

. Dining
person
should

kitchens

especially
Anything

should

in deciding
(or outdoor

counter
space should
wider
will
be hard

be about

l/2

adult

space for each person
(that
is,
space for the
to sit and space in front
of him or her to eat)
be about
l/2 adult
wide and 3/4 adult
long.

COMBINATION
KITCHEN-DINING

l/4 ADULT
%xg

long

36
Let's
look at how the "human measuring
unit"
can be used to plan
several
rooms.
These suggested
plans
may be useful
if a famJ.ly
has problems
picturing
what they can do with
the "pieces"
for a
room.
worker
may want to adapt these
illustrations
( Note: the field
if the furniture
shown here is not relevant
to the local
area)

PLANNING A BEDROOM FOR 1 PERSON
TOP. VIEW

11 ADULT LENGTHS

SIDE VIEW

This

how the

room might

look.

BEDROOM FOR TWO ADULTS

OR PARENTS AND CHILD

OR A COUPLE

1 &ADULT LENGTHS

DINING/FAMILY

ROOM

2 ADULT LENGTHS

Kitchens
may be inside
or outside:
but in either
case,
they must be
big enough to store
all
utensils
and food away from animals,
and to
provide
working
space;
at the
they should
be small
same time,
enough so that
everything
can be
reached
easily
without
many
trips
between
supplies.
Shelves
and cupboards
save floor
space.
In places
where the
kitchen
is primarily
for storage
and most of the cooking
is done
the kitchen
can be
outside,
smaller.

_&-ADULT

Latrines
can be small:
1 m. X 1 m.
However,
if
they are built
longer,
they
will
be easier
to clean
and
to move around
in.
(See the
separate
section
on latrines,
page188
for more details).
1 ADULT SITTING

Door

opens

for

privacy

Bathrooms
to

require
room
dry oneself,

to shower or
and to get

dressed.

1 ADULT LENGTH

A verandah,
or porch,
is really
a room with
2 or 3 sides
open
to the air.
It should
be big
enough to be comfortable
for
social
gatherings,
family,
prayers,
or other
meetings;
this
means at least
one adult
wide and one adult
long
(longer
for large
groups),
so that
there
will
be room to sit or lie
down,
and to walk around
anyone
using
the room.

HELPING
When the
the next
form the

THE FAMILY

DRAW ITS

OWN FLOOR PLAN

number and size of rooms needed have been determined,
step is to decide
how they should
be put together
to
house.

The easiest
way to do this
is to draw a picture
of how the
rooms would
look from above if the roof were removed.
Since
it
shows how the floor-space
in the home will
be divided
among the
rooms,
such a picture
is called
the floor
plan.
One thing
to keep in mind when designing
a floor
plan is to keep
the shape of the building
as compact
and simple
as possible.
Odd
shapes and sharp angles
are more difficult
and more expensive
to build
than either
rectangles
and squares.
Curves
are also
expensive
except
when bamboo,
or similar
materials
are used.
the family's
interest
and confidence
As in planning
room size,
a building
project
will
be greater
if family
members participate
in the drawing
of their
own floor
plan.

The field
worker
can help them
draw the plan by giving
them
scale
model pieces
of paper
or cardboard
representing
the rooms they have planned
and helping
them arrange
the
pieces
in several
different
"floor
plans".
Each possible
floor
plan
should
be discussed
at length
in order
to determine
how
well
it will
fit
the needs
of the family.

When a final
decision
has been reached,
the
room-pieces
can be copied
on a single
sheet
paper then becomes the floor
plan.

arrangement
of paper.

of the
This

42
DRAWING THE FLOOR PLAN OF A HOUSE
Here are some step-by-step
small
family's
house might

Sample

Plan

#l:

House

for

examples
of
be developed.

a couple

A good way to start
a floor
plan,
is to place
the piece
for the
main bedroom
(the room where the
heads of the family
will
sleep)
in the center
of a sheet
of
paper.
For a couple
with no children,
this
might
be the bedroom
This
suggested
on page 37.
size has the advantage
that
a
first
child
could be easily
accommodated
without
cramping.

To this
bedroom might
be added
a kitchen
and a living/dining
area
(both kitchen
and dining
area are shown indoors
here:
if either
or both will
be
the space required
mciy
outdoors,
be very different).
At this
point
been shown in
illustration.

doors
the

have

not

with

how the

no more

floor

than

plan

1 child

for

Storage/Laundry

The home could
be built
on tnls
plan.
But any of several
changes
or additions
to complete
the
If grandsquare
are possible.
parents
or aunts
and uncles
are part
of the family,
they
may require
the main bedroom;
a second bedroom
in which case,
would be needed.
In a nuclear
family,
a shower
some
along with
can be added,
storage
or laundry
space to
complete
the square:

Or, the
a porch:

same

space

can be used

a latrine
should
be
Finally,
planned
near the house,
preferably
where it will
be
sheltered
from public
view,
Storage/Laundry

Sample

Plan

#2:

Holuse

for

a couple

A less expensive
alternative
for
the same couple
would be to build
a single
bed/living-dining
room
using
a screen
to separate
the
two areas
instead
of a wall:

with

no more

III
Latrin

than

1 child.

Sample

Plan

#3:

House for a Small
With 2-a Children,

Extended

Family

A Couple

To design
the floor
plan
for a
slightly
larger
family,
all
the
planner
needs to do is add a new
bedroom to the smaller
homes
shown in Plans#l
and C2.
For example,
the verandah
in
Plan #l could
easily
be remodeled
as a bedroom
for two children
or
an aunt and uncle:

Plan #l could
dining
room,

also
accommodate
the first
bedroom,

a new room either
or the shower:

Storage/Laundry

Kitchen

Bed room

Bed room
Dining

the

In Plan #2, the original
bedroom
can be converted
into
a room for
two children
or grandparents,
and
a second,
smaller
room for the
parents
could
be added on the
other
side of the kitchen
area.
Kitchen

Bath

Bed room

Dining/Bedroom

Sample
Ijere.'s
to if

Plan

84:

House

for

a family

another
plan
for a family
of
the family
continued
to grow:

Future

-o-----w
IT-------II
II
II
II
‘I!
Fut ure Addition

4 or

could

be added

Future

II
!!
Addition

Ki tchen

Bed room

Dining

ii
II
ii.

II
m----I.---*
m-------- 11

II
II

5 that

iition

1I.

Bath

POrch

.Some Points

Remember

About

Floor

Plans.

The kitchen
and dining
areas
should
always
be
next to each other
so that
food can be carried
If dining
will
easily
from one to the other.
the kitchen
should
have an outside
be outside,
door.
In countries
where privacy
is important,
each bedroom should
be planned
with
separate
access
to baths
and/or
indoor
latrines,
so
people
won't
have to pass through
someone
else's
bedroom.
standard
floor
plans
In many countries,
for various
size homes are available
from
the government
or local
architects
and
But check to be sure that
these
engineers.
plans
are appropriate
for lower
income family
needs!

A good way to find
out what makes a good
floor
plan is to explore
homes in the local
area and copy or adapt successful
ideas.
Such a survey
can be especially
helpful
in planning
so that
family
members will
not get in each other's
way when moving
about
the house.

48
Doors,

Windows,

WHERE WILL

and

INSIDE

Ceilings

In All

Buildings

DOORS HE PLACED?

No floor
plan is complete
until
it
shows where the inside
doors
between
rooms will
be placed
and
how people
will
move from room
(For outside
doors,
to room.
see the guidelines
for windows
and special
notes
on page 65.
Inside
to:

doors

should

be designed

provide
between

easy movement
rooms:

provide

privacy

(if

desired).

primarily
Easy Movement depends
They
on the siae of the doors.
should
be one adult
high,
or
and at least
75 to 100
2 meters,
cm. wide for all
rooms except
bathrooms,
which can have narrower
60 to 75 cm.
doors,
One other
factor
that
can affect
ease of movement is how-close
doors
are to other
parts
of the house.
Doors should
be placed
so that
they don't
interfere
with
other
open windows,
or major
doors,
pieces
of furniture
(such as
beds).
Privacy
depends
on how much of a
room can be seen through
the doorThere is no problem
when the
way.
However,
it i.p
door is closed.
often
desirable
to leave
the
door open for air circulation.
Privacy
can still
be maintained
if the door is placed
properly
and opens in the right
direction.
The chart
on the following
shows the right
and wrong
to place
doors
in a room.

page
ways

rF5-l
Ii
N a

49
Door

Placement.

Doors should
of the inside

INCORRECT:

be placed--and
of the room

No privacy
see into

because
room.

hinged-so that
as little
as possible
is‘seen
when the door is open.

passersby

can

CORRECT: View is blocked
by door,
al though
it is left
open
for circulation.

Doors are shown
the door in the
Here
plans

in floor
plans
open position.

of
are some examples
we've
already
seen:

by drawing

a line

representing

how doors

might

be shown

the

floor

51
HOW HIGH WILL

THE CEILING

Ceilings
must be high
that
people
can stand
comfortably.
The best
follow
is to keep the
about l/3 meter
above
or about 2 l/3 meters

BE?

enough so
up
rule
to
ceiling
the doors,
high.

If ceiling
lights
or fans are
planned,
then add about 2/3
more meters
to make the ceiling
at least
3 meters
high.

HEIGHT IF FAN
OR LIGHTS ARE TO
BE IN BUILDING

AVERAGE

In tropical
areas,
higher
ceilings
are significantly
more comfortable
if they are ventilated
to allow
heat to escape.
Buildings
with
unventilated
high ceilings
HOT AIR COLLECTS AND IS TRAPPED NEAR CEILING
tend to be very uncomfortable
..-.
.-: . . . . . . . . ,
.- . ..L l . ,..-,
*.~~..*y,..“‘..,
* .* . ..-\. ;.. . . .:. ..:
because
heat collects
in the
i:Zj~‘3,~~‘~~“:
.‘ii
;.r.;~i..~:oS.i
: c;W..“;
/‘~.I~~
:: space above doors
and windows,
i..g
: y-y:,<
., .!.$ ;“‘..
: f i;>
) : ,.. . .: i !: :<..,
. . . . .._...*... ::..:**.. &I i j
; :
1 i -’ ; . . ‘-:
. . . . :‘:.y
...*
. ..i
making it difficult
to keep the
..*
.,.‘.....
;.. ::.*..- .
,. ~ i
” ...“‘-..
:‘:::’
:~‘:.:.i...”
.’ -“..~
.., ; ; ;
;
-..** :‘pj
, .* :
: : ui‘y?
. . . . ..... ! :-..
rooms cool.
.s
.“.,I
. ; ; ! : :
‘w..I
1: ,,
58

TAKE ADVANTAGE OF ANY BREEZE

For noticeable
must be windows
wall.

circulation,
on more

than

there
one

The building
should
be placed
so
that
the windows
face intc
light
breezes,
but away from
and also away from
harsh winds,
the mid-morning/mid-afternoon
sun.

INCORRECT:

Breeze

CORRECT: Breeze

can’t

passes

pass

freely

through

59
Here are
be placed
position

six situations
showing
how buildings
in
depending
on the direction
of prevailing
relative
to the equator.

the tropics
winds
and

should
the

NORTH OF EQUATOR
Northeast

Southwest

Windows face
catch
breeze
as possible.
All

Other

North
and South to
and avoid
sun as much

Winds.

Windows face Northwest
to avoid
sun and catch
much as possible

/;
..“.~J

Winds.

and Southeast
breeze
as

. ..p
..’
y..: *._. *-

NEAR EQUATOR

-.. . ...+*

Due East
..:*..I;

a
,.
,*.:,
_ . ::-.:..
.:.+ . . . .
I.I

.-i-.1.1.1

.m..-.-

:: . :‘: - .
-. ..:-1.:‘.

-“--‘\
ii.I

1*, %
tIzl
.‘..>::
‘.. -...
-..;.
.-*,
.,*-.
-3
.:W:‘:..
. . . ...* y:‘,
, .-.

WestWinds.

Windows face North
and South
as
much as possible
to avoid
sun, but
they catch
breezes.
All

Other

Winds.

Windows face North
and South
avoid
suni and catch
breeze.

SOUTH OF EQUATOR
Northwest

-, ..a....*
--.-: _
.<-:‘,
*r =.*

Windows face
catch
breeze
as possible
All

Other

Southeast

Winds.

North
and South
to
and avoid
sun as much

Winds.

Windows face Northeast
to avoid
sun and catch
much as possible.

and Southwest
breeze
as

Another
way to increase
circulation
is to use as many
But bear
windows
as possible.
in mind that:
- building
in labor

windows
as well

can be costly
as materials;

- walls
facing
mid-morning
or
afternoon
sun should
not
have more than one window
per room (so as to reduce
heat from the sun).

Th,e size of windows
also affects
circulation
because
larger
windows
.allow more air
in and
out.
Again,

some cautions:

- the larger
the window,
it will
be to build:

the

expensive

- since
there
most likely
will
be times when
the windows
must be closed
with
shutters,
they should
not be much bigger
than about
1 X 1 l/3 meters.
Anything
larger
may put
too much of a strain
on the hinges
and
make the windows
difficult
to open and
close;
- large
windows
offer
thieves
or animals.

less

protection

against

One final
consideration
in getting
the most circulation
possible
is
the height
of the windows.
Most
windows
in tropical
areas
should
cover the upper half
of the wall
so that
any breeze
will
be felt
around
the head and shoulders.
A few additional
windows
covering
the lower
half
of the wall,
especially
in sleeping
areas,
will
further
increase
circulation.
Construction
will
be much simpler
later
if the tops of windows
are
kept level
with
the top of the
door
(about
2 meters).

To sum up, a good
would have:

plan

for

windows
sun;

facing

shades,

overhanging

several
windows,
flow through
the
facing
mid-morning

large
windows
covering
walls
as possible
plus
of the walls,
especially
they are not too large

screens
closed

tokeep
to keep

away

a building
from
roofs,

the

a tropical

mid-morning
or

climate
and

a verandah;

placed
opposite
each other
building
(but no more than
and mid-afternoon
sun);

out
out

mid-afternoon

so wind can
one on walls

as much of the upper half
of the
a few windows
in the lower
half
in sleeping
areas;
(make sure
or heavy to open and close
easily)

insects,
and shutters
that
rain,
wind,
dust,
animals,

can be
and thieves.

WINDOWS IN A DESERT-LIKE

Avoid

Heat

from

The same rules
to windows
in
Windows should
and mid-afternoon.

the
apply
tropical

CLIMATE

Sun.
to

be placed

windows
areas.
to

avoid

desert-like
direct

sun

areas

as annlv

the

mid-morning

Buildings
in desert-like
areas are often
built
around
open courtyards
shaded by trees
and the walls
of the building
itself,
so that
windows
open onto cooler
air
(the same idea is used
too,
but less often).
in tropical
areas,

Buildings
can also.be
placed
close
together
so that
each shades the
walls
and windows
of the building
This may block
some
next to it.
breezes,
but since
winds
in the
desert
tend to be hot and
uncomfortable,
it isn't
so
important
to keep buildings
open
to them.

BUILDINGS

SHADE EACH OTHER

Windows in desert
areas
can also
be protected
from the sun's
heat
by designing
them as openings
self-shading
walls.
in thick,

\
SIDE\/IEW’

sutd CHINES 0~ OUTS1 DE WALL BUT
LITTLE

Protect
since

Windows
so=

~nc-l+
--w-a

from

Uncomfortable

w winds

=s--*-

HEAT & LIGHT

ENTER BUILDING

Winds.

hot

and uncomfortable,
people
want
to be protected
from them
rather
than exposed
to them.
On the other
hand, a building
with no circulation
at all
would
be uncomfortable
and unhealthful.
The best way to protect
against
uncomfortable
wind without
cutting
circulation
entirely
is to plan
small windows
opposite
each
other.

.SMALL

WINDOWS

;:: ,:
i:iiI /a'
,:

:I
ii.-, .,t
:

Protect

Windows

from

Dust

and Glare --

In many areas,
the ground
tends to be dusty.
because
it is often
bare and light
in color,
in strang
glare
that
can be very uncomfortable.

addition,
reflects

sunlight

Both dust and glare
can be effectively
guarded
against
by
placing
smqll
windows
high up from the floor.
This prevents
most of the dust picked
up by winds
from getting
in,
and
blocks
all
the glare.

a good
To sum up again,
climate
would have:
-

windows
afternoon

small,
direct

windows

EXTERIOR

plhn

and doors
sun;
deep-set
light;
placed

for

facing
windows

high

a building
away
to

from

protect

a desert-like

mid-morning
against

against

and midhot

glare

winds
and

and

dust.

DOORS

Like windows,
mind:

exterior

doors

should

be designed

with

climate

a they should
be placed
to avoid heat
from the sun;
they should
be shaded from rain
if they open outward,
or they
should
be designed
to open inward
(otherwise
weather
will.
spoil
the wood or bamboo and cause the door to twist,
warp,
or rot):
I generally
it is worth
the expense
to shade doors
so they
can be opened outward
since
this
is safer
in emergencies
and increases
the amount of
such as fire
or earthquake,
useful
space in the building;
a in earthquake
areas,
outside
doors
should
be placed
close
to the center
of the wall's
length
(see the separate
section
on earthquakes
(page 196).
l

CONSTRUCTION
Schools,
clinics,
number of materials.

MATERIALS
and homes

can

The proper
choice
of materials
considerations,
including:
. the
0

climate:

some materials

the part of the
some parts
need

be built
depends
cannot

out

an almost

on almost

as many

withstand

large

building
(floors,
walls,
roof,
to be stronger
than others;

endless

rainfalls;

etc.):

9 the builder's
budget:
some materials
are much more expensive
than others
for original
construction,
maintenance
and future
additions;
working
on the construction:
some
I the number of people
materials
require
many more people
than others;
. the amount of time available
for
materials
take months to prepare
For any application,
.choose
from that
will
limits
of the builders.
important
consideration
available
at or near
always
less expensive,
use the building,
and

construction:
properly.

some

there
are usually
several
materials
to
be within
the budget,
time,
and labor
Whenever
there
is a choice,
the most
is what materials
(and equipment)
are
the site.
Local
materials
are almost
more acceptable
to the people
who will
more familiar
to those
doing
the construction.

This section
is designed
to review
basic information
most common materials
that
small
rural
communities
to find
nearby.
Detailed
directions
in the use of
will
be found in later
sections
covering
the actual
process
(pages 115-180).
But once builders
know
discussed
here,
a brief
will
usually
be enough

the major
characteristics
survey
of what is locally
to decide
what to use.

about
the
are likely
these
materials
construction

of the materials
avaiiable

Rammed

Earth

(Mud,

Pise)

and

Adobe

Blocks

Rammed earth
is a combination
of sand,
silt
and clay
that
properly
pressed
and dried
is suitable
for walls
in dry
(wet climates,
too, when protected
with
lime plaster.)
sand,
silt,
and clay are locally
available,
rammed earth
adobe blocks
are two of the least
expensive
materials
to

when
climates.
If the
and
use.

Basically,
by volume:

ratio

the

ingredients

80%

30% clay;

. 15% silt
The amount
determined
a mud that

sand

(the

(extremely

are
most

mixed

with

water

this

important);

fine-ground

rock).

of water
needed varies
considerably
and must be
by making several
tests.
There should
be enough
holds
its
shape but can still
be molded,

make

@nce the ingredients
are mixed
thoroughly,
they are pounded
with
a thin
pole into
a portable
mold (form)
2/3 to 1 meter high
until
they are packed
solid.
The mixture
is then allowed
to
cure
(dry)
thoroughly.
When
one section
is ready,
the mold
is removed
and used to' form the
next section

RAMMEDE ARTH FORM W

CRETE/BLOCK FWN DAT I ON

Adobe bricks
are individual
solid
mixture
of ingredients
as rammed

blocks
earth.

made from

the

same

A simple
form
- or mold is used to shape the bricks,
which
must be dry for at least
a month before
use.
Because
of the
drying
time needed,
adobe bricks
can only be used where there
is a long season of hot dry weather.

ADOBE FORM
\I

Construction
and highly
especially
volunteer

with either
rammed earth
or adobe is inexpensive
labor
intensive.
This makes both materials
good in low-income
communities
that
can contribute
labor.

Rammed earth
and adobe should
never be used underground
foundations,
since
underground
moisture
will
eventually
them.
Both materials
are excellent
for walls,
however,
withstand
rainfall
if protected
with
lime plaster.
In earthquake
areas,
with wood, wire,
or

rammed
bamboo.

earth

and walls

must

Finally,
rammed earth
and adobe structures
cannot
roof
loads
without
strong
wood or iron
reinforcement.
roof materials,
such as thatch
or bamboo,
are the
with either
rammed earth
or adobe brick
walls.

for
weaken
and can

be reinforced
support
best

heavy
Light
to use

Wood
wood is one of the most versatile
and durable
construction
materials.
It is easy to work with
and can be used to build
almost
any part
of a structure.
Due to deforestation
of many
countries,
however,
wood is too scarce
and expensive
for use by
most low-income
communities
as their
main construction
material.
Field
workers
in countries
like
Thailand
or Malaysia
where wood
is still
plentiful
may wish to consult
one of the many excellent
books-describing
wood frame construction
listed
in Appendix
7.
Over the long-term,projects
to re-plant
forest
replenishable
source
of wood for construction
desirable.
But most communities
now will
only
wood as a secondary
material
for:
.
.
o
.
.
e

areas
as a
(and fuel)
are highly
be able to afford

roofs;
doors
and door frames;
shutters,
windows,
and window
frames;
porch
railings
and posts;
wall
reinforcements
(especially
in earthquake
forms for poured
concrete,
blocks,
temporary
braces,
and scaffolding
for roof
construction.

The best timbers
some resistance

to use are generally
those
to decay,
rot,
and termite
- Lignum vitae
(West Indies)
- Honduran
Mahogany
- West African
Odum and Okan
- Asian
rosewood
and teak.
Some softer
woods,
such as Eucalyptus
Pine,
When in doubt,
a survey
of nearby
buildings
which
local
timbers
have proven
successful.

that
attack,

areas)
frames

and

are hard and
such as:

have

denya
are also quite
good.
may help to determine

‘d

Bamboo is an excellent
material
except
the foundation.
Where
inexpensive.
Its
light
weight
generally
easier
than wood.
Bamboo must be used with
great
loads
or excessive
water,
it cannot
be used

for almost
any part
of a building
available
it is usually
very
makes it very easy to work with--

care,
however,
because
it cannot
support
dampness
or rain.
Because
it decays
in
underground
for a foundation.

Since
construction
with
bamboo is very
with
other
materials,
it is covered
in
beginning
on page 181.

different
a separate

from construction
section

Stone

and

Rock

Piles
of stone and rock
can be
used to make strong
foundations
and walls,
especially
if used
with
a cement-based
mortar
to hold
them firmly
together.
Stone and rock
disadvantages,
l

have several
however:

if not locally
abundant,
they are expensive
to
obtain;

e walls
made with
rock or
stone
have many uneven surfaces.
Filling
in the large
cavities
in order
to made inside
walls
smooth is time-consuming
and
expensive;
o walls
of rock/stone
must
be thicker
than cement block
walls
if they are to be
equally
strong;
l

building
to precise
measurements is difficult
or
impossible;
builders
planning
to use rock/stone
should
plan slightly
larger
rooms
and construction
sites
to
ensure
that
the finished
building
will
be large
enough.

Cement

and

Materials

Made

With

Cement

Cement is an adhesive
material
that
l'bondsV' or glues
objects
such as rocks
or grains
of sand together
so that
they form a
strong
permanent
piece.
A useful
cement can be made locally
from finely-ground
limestone.
But commercial
cement:;
also
contain
silica,
alumunum,
and iron
oxide.
These materials
ensure
that
the mixture
will
contain
a variety
of grain
sizes
The more different
grain
sizes
there
are! the stronger
the cement
will
be.

71
cement
is
Because of its bonding
action,
in many construction
materials
including:
. mortars
l
concrete
- poured
- reinforced
. blocks
- concrete
blocks
- sand-cement
(sand-Crete)
blocks
- stabilized
earth
blocks
Each of

these

materials

cement is used
Generally,
as
an
ingredient
in
a
blocks,
or stones,and
. as an ingredient
in

discussed

used

as an ingredient

below.

two ways:
(pastes
used
mortars,
to plaster
walls);
concrete.

bond

bricks,

Mortars
Mortar
is a general
term for any
mixture
of cement with
sand and either
lime or clay.
The ingredients
are mixed in
varying
proportions
with
water
to form a paste
that
can be used:
- to bond
rocks;
- as a wall
stucco).

bricks,
finish

The tables
in Appendix
recommended
proportions
different
mortar
uses.

blocks,

(plaster,
5 give
for

Concrete
Concrete
gravel,
together
cement.

is a mixture
of sand,
and water
that
is held
and given strength
by

The strongest
concrete
has
particles
ranging
from very fine
across
sand to gravel
of 3.75zeters
rs
Some builders
and manufacture
refer
to the sand as fine
and the gravel
as
aggregate,
coarse
aggregate.
ENLARGED CROSS SECTION Of CONCRETE

wood forms must be carefully
Before
concrete
can be poured,
When the
built
to hold it in the exact
size
and shape desired.
formwork
is ready,
plain
wet concrete
is mixed,
poured
in the
and allowed
to cure
(dry)
for a few days to a few weeks
forms,
(depending
on the weather
and type of construction).

Plain

poureu
concrete
can be used to build:
footings
(pads of concrete
a foundation
building's
weight
over a wide surface);
. blocks

for

foundations

that

distribute

and walls;

. floors.
and gravel
vary according
to
The proportions
of cement,
sand,
But these proportions
are
the planned
use of the concrete.
For example,
always
referred
to in the same way by builders.
1:2&:3,
means concrete
a formula
often
used for foundations,
composed
of 1 part
cement,
22 parts
sand,
and 3 parts
gravel.
A builder
usingthis
formula
would need 24 wheelbarrows
of
sand and 3 wheelbarrows
of gravel
for every wheelbarrow
of
cement.
In addition,
he/she
would need approximately
23 liters
of water
to be added to the mixture.

Reinforced

Concrete

Reinforced
concrete
combines
materials
with oppositecharacteristics:

two

. plain,
poured
concrete:
resists
downward
pressure
(compression),
but will
not
bend;
it cracks
instead;
. iron
have
will

CONCRETE ALONE IS NOT STRONG ENOUGH

will
bend (they
rods:
tension
strength),
but they
buckle
under compression.

Reinforced
concrete
is prepared
and
handled
as plain
concrete
is, except
that
an iron
rod, or a series
of
rods,is
fastened
inside
the
form before
the concrete
mixture
(In some cases,
is poured
in.
bamboo stalks
can be used for
reinforcement
in place
of iron
rods.
See -page
188).

Reinforcing
concrete
or bamboo is fairly
multiply
the strength
2 to 5 times
in:

either
with
iron
easy and can
of the concrete

walls;

support
walls
and ceilings;

un-supported

such

sections

as overhangs

balconies.

Blocks
A variety
of blocks
can be made by combining
cement with other
ingredients.
All these blocks
are useful
for foundations
and
walls
and can be produced
locally
if the proper
ingredients
are available.
They can either
be made by hand or with a simple
press.
A press is generally
more efficient
and produces
a
stronger,
more tightly-packed
block than can be made by hand.
Whether made by hand or press,
the blocks
can be solid
or hollow,
depending
on the mold chosen.
Hollow blocks
use considerably
less material,
reduce weight,
and improve insulation.
They are
not as strong
as solid
blocks.
But in sections
of a building
where additional
strength
is required,
the hollow
parts can easily
be filled
with poured concrete
or other reinforcing
materials.
TWO BASIC BLOCK-MAKING PROCEDURES
J/By

By
#l
#2
#3

Hand.

#l Gather and Mix Ingredients
#2 Pour Mixture
in a Mold
#3 Pack Mixture
Tightly
in Mold with
Shovel
#4 Add More Mixture
and Pack Again
#5 Remove Mold
#6 Cure (Dry)

Hand-press.
Gather and Mix Ingredients
Pour Mixture
in a Mold
Pack Mixture
Tightly
in Mold
with Press
#4 Add More and Pack Again
#5 Eject Block from Press
86 Cure (Dry)

Concrete

Blocks

Concrete
blocks
are excellent
for
foundations
and walls.
They are
made from a mixture
of 1 part
cement,
2 parts
sand and 4 parts
gravel.
As manufactured
commercially
they:
are usually
among the strongest
blocks
available
(in fact,
they
are stronger
than necessary
for
l-story
buildings);

have excellent
qualities;

insulating

. are the most uniform
blocks
(important
for accurate,
durable
construction).
However,
expensive
use.

they are by far the most
block
a community
could

Concrete
blocks
can be made locally
if limestone
(or commercial
cement)
sand,
and gravel
are available
in large
quantities
near the site.
The process
is simple,
but timeconsuming.
Generally,
the blocks
must be made about a month before
they can be used for construction.
Sand-Cement

Blocks

Sand-cement
blocks
parts
sand.
They
some reinforcement,
buildings.

(Sandcrete)

are strong
blocks
made of 1 part
cement to
cannot
be used to support
.roof loads
without
but are more than adequate
for l-story

6-8

Because of the high proportion
of sand needed,
sand-cement
blocks
are only practical
for construction
where there
is a lot of
sand (sand-cement
blocks
are not generally
made commercially).
But if the sand is available,
sandcrete
block-making
is a quick
and efficient
process.
Sandcrete
blocks
only take 12 days to
cure
(dry),
less than half
the time required
for concrete
blocks.

Stabilized

Ezwth

Blocks

These are blocks
in which
clay soil,
rather
than sand,
is mixed
cement or lime.
with
either
The amounts
of cement
and soil
needed for a good mixture
can only be determined
by testing
how much the soil
shrinks
when dried
(the procedure
is simple
and can be followed
easily
by any community
group).
The blocks
are formed in the same
way as sand-cement
blocks
and can
be used for all the same purposes.
They are especially
suited
for lowcost construction
in areas where
sand is not available
in largeenough quantities
for sandCrete.
However,
great
care must
be taken
to keep organic
material
out of the clay soil
used in the
mixture.
Otherwise
the mixture
will
not form a strong
bond.
(This too can be done with
a
simple
test
of local
soil
samples.
See page 146).
Stabilized
used after

earth
only

blocks
S days

can be
of curing.

Summary
In surveying
in mind that:
l

locally

available

adobe brick
is best
concrete
foundation

materials,

for dry,
hot
and protection

sand-cement
blocks
require
cement and
stabilized
and about
the right

but require
materials;

are strong
and
a lot of sand;

earth
blocks
are cheaper
as strong;
but care must
mix of soils
is available

. concrete
blocks
are good but very
commercially;
they can be produced
to prepare;

areas but
against

rammed earth
walls,
though
made of
adobe brick
walls,
are not as strong
stone
and rock are good
than other
construction

the
or

needs
rain;

keep

a rock

same ingredients
as permanent:

more
easy

useful

heavy,
make,

hard
but

than sand-cement
be taken
to see
in the area;
expensive
locally

if
but

or
as

work
they
blocks
that

purchased
take a month

plain
poured
concrete
is a strong
and versatile
material
especially
suited
to foundation
footings,
foundation
walls,
it can be made inexpensively
in most communities
and floors;
if limestone
or commercial
cement is available;
reinforced
material
earthquake

concrete
is the
all
(especially
areas).
But it

strongest,
longest-lasting
in wet and stormy
climates
is ~eryexpensive.

and

IhED

PLANNING

FOR C!QNSTRUCTION

After
the size and floor
plan of a new building
have been decided
on along with
its
site
and position;
and after
a preliminary
assessment
of the construction
materials
that
may be used has
been made, the next crucial
step is to develop
detailed
written
plans
(or blueprints)
to guide each part
of the construction.
These plans
must answer
several
questions
about each part
of
the building
from the ground
up:
FOUNDATIONS
l

How deep

the

How thick

How high

must

. What will
reinforced?

the

ground

must

the

foundation

be set?

be?

foundation

be made of?

Will

FLOORS
l

Will

the

floor

be made of

. How much should
ground?
. How thick

cement

be raised

should

above

packed
the

I
i

earth?

level

surrounding

be?

WALLS
* What will

the

. How thick

should

walls

be made of?

they

be?

Should

How will
window and door frames
they be placed
in each wal:?

they

be reinforced?

be made and

exactly

where

several

angles?

ROOFS
. What will
l

Will

the
be flat,

roof

be made of?
set

an angle,

set

will

Many
design
walls
roof
plan
make
walls

these
questions
are interrelated.
For example,
the
of the foundation
depends
in part,
on the weight
of the
and roof
it must support;
and the design
of the walls
and
in order
to
depends,
in turn,
on the foundation.
Thus,
the construction
effectively,
the builder
must be able to
some basic
decisions
about either
the foundation
or the
and roof
before
determining
all
their
exact
specifications.

When in doubt
about a detail
of the construction
plans,
the field
worker
or community
member may want to seek advice
from an
experienced
local
contractor.
In most cases,
however,
construction
plans ~o~be drawn successfully
for simple
l-story
buildings
by anyone
following
the suggestions
in this
manual.
This part
community

of the manual
member,

designed

help

the

field

worker

Q first,
to understand
key methods/principles
and key technical
characteristics
of basic

of construction
materials;

how these principles
basic
design;
and

second,
to proceed
and characteristics

. third,
plans.

actually

step-by-step
to
should
influence
draw

his/her

consider
their

own detailed

construction

PLANNING

FOUNDATIONS

If the walls
of a building
are
built
directly
on the ground
the weight
of the
surface,
building
will
soon press
them into
the earth.
This causes
the
building
to sag, crack,
or leak.

r --mm----t WALL

Foundations
are strong
platforms
built
below ground
level,
where
they won't
sink.
A building
with
a foundation
can "stand"
securely.

1I
I

b FOOTING
I
L-

-e------

I
i
PLAN VIEW

The foundation
of a wellconstructed
building
does
several
things:
it provides
a level
for the building
to

a it
if
or
l

helps
earth
rains

it keeps
ness.

platform
stand on;

protect
the building
tremors,
strong
winds
shake the structure;
out

water

and dampELEVATION

Here's
a list
of things
foundation
must NOTdo:
l

sag;

dissolve

crack

slip

buckle

(or
from

rot)

stress

the
NOTE: The footing
around
the

by water
at

erosion;

a certain

on uneven ground

under pressure
of water
ground
(this
is called
"scouring");

in the

. collapse
from
the building.

the

VI EW

weight

point;

continues
building

wall
can be made of many different
materials.
Each material
must
be planned
for in a different
way.
There are other
foundation
designs
such as pier
and beam, or
post and beam that
communities
with
access
to heavy wood beams
might wish to use.
See
Appendix
7 for reference
materials
that
discuss
these
designs.
Note:

INCORRECT:

not

square

Footings
All

foundations
should
have a
footing.
The concrete
can be poured
directly
into
the
foundation
trench,
or into
wooden
forms in the trench.
In either
case,
the bottom
of the trench
must be ZeveZ and the sides
of
the trench
or of the kooden
forms must be square:
that
is,
they must be exactly
,vertical,
at 90° to the trench
bottom.
emcrete

TRENCH

5cm x 1Ocm spacer
to secure
the form

5cm x 1Ocm or 5cm x 25cm boards
angles
to the trench
botLzi”
ang1e’

at right

247-801

0 - 77 - 7

CORRECT: square

The depth
the footing

the
rests

trench
in which
depends
on:

. what the foundation
wall
is made
of;
. the stability
and strength
of
the soil:
line
(this
only applies
0 the frost
in areas where temperatures
drop below
freezing
in winter;
the frost
line
is the maximum
depth
to which soil
freezes
locally);
4 the unevenness
and/or
slope
of the ground.

The wCdth and thickness
footing
depend
the foundation
Foundation

on what
wall
is

of the
material
made of.

Walls

The foundation
walls
can be made
of rock,
or they can be made of
blocks
of concrete,
sand-cement,
or stabilized
earth.
All of these
materials
are strong
enough to support
the walls
and
roof of most l-story
buildings.
The choice
depends
on *what
materials
are available,
the
builders'
budget,
and whether
or
not earthquakes
or severe
weather
conditions
will
require
reinforcement
in the foundation.
INCORRECT:

Rock Foundation
Walls.
A rock
foundation
wall
is built
by setting
stones
that
are 20 to 40 cm.
long in mortar.
The rocks
must
be cleaned
so that
no rocks
remain on them.
AZ2 the spaces
between
the rocks must be filled
with
mortar
(these
spaces
are
called
"joints").
In addition,
and most important,
they must be
laid
so they overlap.
If a
straight
line
can be drawn between
the rocks
from the top to the
bottom
of the wall,
a crack
will
develop.

A crack

CORRECT: Overlapped

wi 11 develop.

durable.

Rock foundations
are the least
However,
they
expensive
to build.
require
a large
number of rocks,
and it
is difficult
to clean,
and overlap
the rocks
level,
properly.
If the building
position
is on
rocky
ground,
or on dry,
wellpacked clay
soil,
the footing
for
a rock foundation
wall
should
be
4 to 8 cm. thick.
In less stable
soils,
such as
the footing
sand, or gravel,
should
be at least
10 cm. thick.
In soft
black
soil,
drained
and made earth,
the
marshland,
footing
should
be reinforced
and
should
be 10 cm. thick.
In rocky
or hard-packed
clay
soil,
rock foundation
walls
need only be
In other
soils,
30 cm. deep.
they should
be at least
45 cm.
deep.
Rock foundation
walls
should
be
at least
30 cm. thick,
and they
will
be much more stable
if they
are flared
at the base to 45 cm.
Whether
Block Foundation
Walls.
built
of concrete,
sand-cement,
or
stabilized
earth,.block
foundal
tion
walls
are made by laying
level
rows of blocks
on concrete
footings
until
the wall
reaches
the
the planned
height
of the floor.
Each row of blocks,
called
a
cowse , is joined
by mortar,
as are the ends of each block.
Block
foundations
cost more to
build
than rock foundation
walls
(except
in areas where the rock
must be transported
over large
distances),
but block
foundation
walls
can be put up faster,
and
they are easier
to build
well.

M 4CM

45cm

In rock or firm clay soil,
a
block
foundation
should
be 45
In less stable
to 60 cm. deep.
a block
foundation
shouZd
soil,

NOTbe used.
The width
and thickness
of the
footing
depend on the size of the
In general:
blocks
being
used.
.

the footing
should
be as thick
as the blocks
are wide;

the footing
should
be
as wide as the blocks.

3 times

The frost
line
is the
Frost
Line.
depth
to which
the ground
in any
area freezes
in the winter.
In
climates
with
freezing
temperatures,
the footing
must be entirely
below
the frost
line.
The table
depths
to
frost
line

below gives
suggested
be safely
below
the
in different
climates:

Lowest
Temperature
in Winter,
Degrees
Celsius

Safe Minimum
Depth for Top
of Footing

-lo

45cn.

-so

75cm.

-1lO

90cm.

-18O

1.05m.

-22O

1.2om.

-28O

1.30m.

Ground.
If a building
Sloping
-will
tend to slide
downhill,
Thus if
to slip
and/or
crack.
or is uneven,
the trenches
for
completely
levelled.
---------

----

---

is built
at an angle
on a slope,
causing
the foundation
and walls
the ground
under
a building
slopes
the foundation
footing
must be

DIRECTION
-------

If the ground
slopes
sharply,
it
"step"
the trenches.
When block
it's
important
to make each step
of blocks.

OF SLOPE b
----------

---

may be easier,
or necessary,
to
foundation
walls
are planned,
the height
of one or two courses

Deciding

Upon

the

Ma+-Gals

and

Qimensions

for

Foundations

In general,
the best way to decide what the foundation
walls
will
be made of is to choose the least expensive
and most easily
accessible
material.
Once the choice has been made between rock and blocks,
the
depth of the trenches
and the dimensions
of the footing
and
foundation
wall may beqprozimatety
determined
by using the figures
outlined
on pages 85-86.
It is important
to remember, however, that these preliminary
figures
are only approximate
guidelines.
Any number of local
conditions
can make a deeper, stronger
foundation
advisable.
One of the best ways to determine
whether preliminary
foundation
plans are safe is to compare them with the foundation
structures
of buildings
in the local area.
The field
worker or community
member should ask:
, How deep are the foundations
of buildings
that have cracked
walls or other signs of weakness?
How deep are the foundations
of buildings
that have lasted well?
0

How wide and thick
are the foundation
of weak buildings
? Of strong buildings?

footings

and walls

. What are the foundations
of weak buildings
made of?
are the foundations
of strong buildings
made of?

What

If preliminary
plans for the foundation
are similar
to those
of strong buildings
built
nearby on the same kind of soi1.i.n
the
local area, they should be safe to use.
If the preliminary
plans
are similar
to those of weak buildings
they should be strengthened
before the start
of construction.
Drawing

Final

Foundation

Plans

After the materials
and dimensions
of the foundation
have been planned,
the last step before construction
of the foundation
can begin is
to draw a final
foundation
plan.
The plan
drawings:

should

include

two simple

- a scale drawing of the footing
and foundation
wall as they
would look in a cross-section;

4
-W

FOUNDAT I ON WAL:
FOOT I NG

- a scale drawing of the footing
and foundation
wall measurements
as they would look if seen from
above.
Both these drawings are simple to
Step-by-step
produce with a ruler.
instructions
will
be found in
Appendix 2.

I
OUNDAT I ON WA

E
9

To be comfortable
and safe, the
floor
of a building
must be:
0 dry;
. level;
l
smooth, but not slippery:
movement should not be
obstructed
by holes or bumps,
but the surface should not
become slippery
when wet.
The most important
keeping the floor

of these
dry.

In many climates,
the ground
under a building
will
be damp,
even in periods between rainfall.
WATER

In areas of heavy rainfall,
if the
floor
is at or close to ground
level,
water will
come in under the
doors and damage the floor.
For both these reasons,
the floor
of all buildings
in areas where
there is heavy rainfall
should
be raised at least 20 to 30 cm.
above ground level to protect
it
from moisture.
The best way to do this
"dry fill."
Dry
fill
is
of any material
that will
water.
Typical
materials
dry fill
include:
small
broken bricks,
clumps of
earth, and gravel.
Types

is with
a layer
not hold
used for
stones,
hard
ICORRECT: Raised

of Fkxws

Two basic types of floors
will
discussed
in this manual:
. hard-packed
earth floors,
0 concrete.
In areas
supplies,
good.

with large local wood
wood floors
are also

Prevent

Flooding

HARD-PACKED EARTH FLOORS
Hard-packed
earth floors
are much
less expensive
than concrete.
They are adequate in dry climates,
but can be uncomfortable
and
unhealthy
in wet climates
or lowlying areas, even when ample dryfill
is used.
Earth floors
must be made from
hard earth taken from below ground
Soft topsoil,
or any soil
level.
containing
organic material
will
The hard
not pack well enough.
earth should be placed above the
dry fill
in a tightly-packed
layer
lo-15 cm. deep.

CONCRETE FLOORS
Concrete floors
cost more than hardpacked earth.
They are also stronger
and much better-suited
to wet climates
and low-lying
areas.
A concrete
floor
is made simply by
pouring
a layer of concrete
over
the dry fill.(Hard
laterite
is the
best kind of fill
for a concrete
The.best
thickness
of the
floor.)
concrete
layer depends on the
planned use of the floor
(see
table on right).

Suggested Thicknesses
of Concrete Floors
Purpose
floor
house,
school

Thickness
cm.

clinic,

garage
(for vehicles)

12.5

farm storage
(heavy equipment)

92
In locations
where the ground is very unstable
or uneven,
earthquake
zones, a concrete
floor
might need reinforcement
flexibility
and additional
strength.
Estimating
To
,to
the
of
for

the Amount of Concrete

Needed for

or in
for

a Floor.

determine
whether the builder
can afford
a concrete
floor,
and
be sure of buying enough materials
without
buying too much,
field
worker or community.member(s)
should make an estimate
how much concrete will
be needed.
Step-by-step
instructions
the calculations
needed will
be found in Appendix
3.

PLANNING

WALLS,

WINDOWS,

A cqlete,
detailed
walls
(both exterior
of:

AND

DOORS

plan for the construction
of a building's
and interior)
would include
descriptions

the material

they'll

their

height;

their

length;

their

thickness

be made of;

placement
of windowsp doors;
_I
. the construction
techniques
to be used, especiallyaround
doors and windows,
and where any two walls meet;

the exact

the use of reinforcement
(if
withstand
the stress of very
earthquakes:

an estimate
construction.

of the

any)
soft

to help
ground,

amounts of materials

The basic plan and design of the walls
already
specify
many of these features,
the outer walls will
be made of, their
placement
of doors and windows.

the building
high winds,
needed

for

developed earlier
should
especially
the materials
dimensions,
and the exact

However,, especially
when blocks or bricks
will
be used for the
walls,
some changes may have to be made before construction
can begin.
To avoid expensive mistdkes
or problems during
construction,
a detailed
construction
plan of the walls should
be prepared.

Wall

Height

end

Length

When the walls will
be made of rammed earth,
stone,
concrete,
other than block or bricks,
the
bamboo, or any other material
height
and length of the walls should be exactly
as planned in
the basic wall design.
However, when using blocks of any kind (adobe, sand-cement,
it may not be possible
to build
a wall exactly
cement, etc.)
height and Zength planned.

if the blocks used will
For example,
measure 12 cm. high, a wall could
be 2.88 meters (24 blocks)
high
or 3 meters (25 blocks)
high;
but it couldn't
be 2.96 meters high
unless one layer df blocks was
and this is difficult
cut in half,
to do.
In the same way, if the
blocks used will
measure 40 cm.
a
wall
could
be 7.20 meters
long,
(18 blocks)
long or 7.60 meters
(19 blocks)
long; but it couldn't
be 7.35 meters long unless one
block in each layer of the wall
were cut 5 cm. short.

2.88m

(24 Blocks)

the

211

and much less expensive
if the
Construction
is much easier,
height
and length of block walls are adjusted
so that they
can be made from a whole number of blocks.
To determine
how much the height and length of the walls
to be adjusted
(if at all)
simply follow
these steps:
STZP I:

needs

Divide the planned height of the wall .by the height
of
one block.
If the answer is a whole number, the wall can
The result
be built
as planned without
any adjustment.
of the division
will
equal the number of layers
(courses)
of block needed to reach that height.
Example:

The planned height of the.waZZs
us&~-22 cm.'high bLocks:

Ls 2.88 meters

288 i 12 = 24cou.rses

(288 em.);

of blocks

If the answer is a whole number plus a remainder,
compare
the remainder with the height
of one block and round off
to the nearest whole block.

94
Exam@?e: of the planned heks high.
STEP 2:

The procedure
for adjusting
the length of a blor?k wall is
similar
to the procedure
outlined
above for adjusting
the height:
divide
the planned length of the wall by the
tength of one block.
If the answer is a whole number, with
no remainder,
the wall can be built
as planned without
The result
of the.division
will
equal
any adjustment.
the number of blocks needed to reach that length.
#!iMlpZe: If the ~~LVUWI length of the natt is
U8iw
40 an. hq blocks:
720 ; 40 = 18 blocks

7.2 meter8 (720 Qn. i,
Zag

If the answer is a whole number plus a remainder,
compare
the remainder with the length of one block and round
up or down to the nearest whole number of blocbs.
Wall

Thickness

The thickness
l

of a wall

on three

things:

whether the wall is exterior
or interior:
interior
walls.
usually
do not support the weight of the roof and can
therefore
be thinner;
interior
walls also play a less
important
role in insulating
the building
from heat and cold;

. what the wall
can be thinner
l

depends

the climate:
walls,
while
walls.

is made of:
than walls
buildings
buildings

walls made of stronger
materials
made of weaker materials;

in desert-like
in tropical

climates
need thicker
climates
need thinner

The table below suggests minimum thicknesses
for different
kinds
The figures
given should be adequate for most l-story
of walls.
However, if there is any doubt
buildings
(up to 5 m. X 9 m.).
about the load-bearing
capacity
of the walls in a special
design,
advice from an experienced
local contractor
should be sought.
SUGGESTEDWALL THICKNESS FOR DIFFERENT MATERIALS
Exterior

Material

37.5-45 cm.
30 cm.
12.5-20 cm.

Rammed Earth
Adobe Brick
Poured Concrete
(not reinforced)
Poured Concrete
(reinforced)
Stone
Block (sandcement, stabilized
earth,
cement)
Placement

of Doors

Wall

12.5 cm.
30-37.5 cm.
20 cm.

and

Interior

Wall

37.5-45 cm.
30 cm.
12.5-20 cm.
12.5

cm.

25 cm.
lo-15 cm.

Windows

As with the height and length of walls,
the exact placement
and size of windows and doors may have to be adjusted
to make
construction
easier.
No adjustments
need to be made when the
walls will
be made of rammed earth,
stone, concrete,
bamboo,
or any other material
other than block or brick.
However, when using blocks of any kind (adobe, sand-cement,
cement, etc.)
the size and placement of windows and doors should
be planned,so
as to make them even with the courses of blocks.
ADJUSTING THE SIZE OF WINDOWS, DOORS
The procedure
for adjusting
the height
and width of the space
for windows and doors is exactly
the same as the procedure
for
Simply think of the
adjusting
the height and length of a wall.
windows and doors as though they were walls to be built
with
blocks.
Then, following
the procedure
described
on pages 93-94,
increase
or decrease the height
and length of the windows/doors
as necessary.

For example, suppose a window is
planned so that it will
begin
135 cm. from the bottom of a wall
made of 10 cm. high x 20 cm. thick
x 40 cm. long blocks.
135 cm. would
be 13s layers
(courses)
of blocks
high.
So rather
than cut a whole
layer of blocks to fit the window
height,
it is much easier either
to raise or lower the window 5 cm.
so it will
start
130 cm. (13
courses)
or 140 cm. (14 courses)
from the bottom of the wali.
Construction

Details

for

Dams,,

LOCAT I ON
LOCAT I ON

Windows,

an,d

interior

DOOR AND WINDOWFRAMES
The construction
plan for walls
should show how the door and
window frames will
be attached
to the walls.
Window and door frames are made
of wood (5 cm. thick wood is
best) to fit the exact size of
the wall opening.
The frames
are permanently
attached
to the
walls,
and then the windows and
doors are attached
to the frames.

WINDOW FRAME

DOOR FRAME

Walls

Frames that are nailed
right
to the
masonry or concrete
of the wall are
the best for preventing
drafts
and
But they may also be
leaks.
attached
to the wall by placing
wooden slats
in the mortar joints
and nailing
the frame to the
slats.

WINDOW FRAME

LINTELS
Lintels
are short beams that should
'always be used to support
the wall
over an opening for a door or
window.
Lintels
are usually
as
thick as the wall.
In rammed earth or adobe brick
walls,
the lintels
may-be made of
They
5 cm. thick
wood beams.
should extend past the window or
door opening about 20% of their
length,
or a minimum of 2C cm.
on each side.
In walls made from any other
material,
except bamboo, the
lintel
should be made of reinforced
concrete
(use two steel bars for
Construction
reinforcement).
will
be much easier
if the lintels
are "pre-cast":
that is, made in
advance and then placed in the
wall like a brick.
(For bamboo,
see the section
on bamboo construction,
page 181)
In block walls
the lintels
should overlap
the
opening 3 the length of a
block on either
side of the
frame.
l

-T-

I INTEL

IN WOOD FRAME

REINFCRCEMENT

BARS

INTERIOR WALLS
RECOMMENDED

Interior,
or "partition"
walls do
not support the weight of the roof,
Thus they
as the exterior
walls do.
are often thinner
than the outer
or made of 'a different
walls,
However, they
material
completely.
must be attached
to thrt outer walls.
This can be done after
the outer
But it is
walls have been built.
usually
better
and easier
to build
all the walls at the same time.
This is especially
true when the
walls will
be made of blocks or
bricks.
The wall construction
plan should
include
a diagram showing how the
partition
walls will
be attached
to
the outer walls=

REISJFORCBMENT

EXTERIOR WALL

-NOT

EXTERIOR WALL
A INTERIOR WALL

RECOMMENDED:
WEAKER

, , .. . .

In areas where buildings
are
exposed to stresses
suqh.as high
winds, severe storms,
freezing
and high humidity,
temperatures,
walls should be reinforced.
Effective
reinforcement
will
increase
the life
of any building
significantly.
Often it enables the
builder
to construct
thinner
walls
and save money on materials.
In earthquake
areas, walls MUST
be reinforced.
(See the,section
on construction
in earthquake 'zones
for special
reinforcement
techniques
not shown here, page 195).
_,
Rammed earth and stone walls are
very difficult
to reinforce
effectively.
Block walls can
be reinforced
in several
ways:
l
steel rods can be run along
the horizontal
joints
of the
wall.: the rods should be.1 to
1.25 cm. thick:
where they overthe
overlap
should be at
lapI
least 25 cm.

.lN

RE I N FORCEMENT BARS
MORTAR JOI NTS
(overlap
25cm Minimum)

. barbed wire is an effective
reinforcer:
it is run, like
the steel rods, along the
top of each course of brick:

. if hollow blocks are used, the
holes in the corner blocks can
be used to run steel rods from
the foundation
up to the roof;
then the holes can be filled
with concrete;
REINF

RING
RE INFORCEMEN
TOP OF

"ring beam" can be run
around the top of the walls:
this is usually
a 15 cm.
thick band of concrete
with
2 steel
rods that runs
continuously
(without
seams)
around all four walls.
Ping
beams are mandatory in
earthquake
areas.
(See
page 200).

RE I N FORCEMEh-J’ BARS

Poured concrete
walls are often
reinforced;
the exact thickness
and arrangement
of the
reinforcement
bars should be
determined
by an experienced
local builder,
but this is the
method most commonly used:
Steel rods ranging from l-2 cm.
are arranged horizontally
and
vertically,
lo-20 cm. apart.
They are fastened
to each
other by lightweight
flexible
wire
and are wired in place temporarily
until
the concrete
is poured.
Concrete that has been reinforzed
has from 2 to 5 times the strength
of unreinforced
concrete.
This
means that,
for example, a 10 cm.
thick reinforced
concrete
wall will
be as strong as an unreinforced
wall twice as thick.

RE I NFORCEMENT RODS .

POURE:D CONCRETE w

ESTIMATING MATERIALS tiEEDED TO BUILD WALLS
Before construction
can begin, the builder
needs to estimate
how much of each of the materials
to be used will
be needed
so that all the supplies
can be purchased or assembled in time.
Details
of the calculations
involved
will
be found in Appendix
4.

PLANNING

ROOFS

When the basic design and construction
plans for the foundation,
and walls are complete,
the field
worker and community
floor,
member(s) should consider
what kind of roof the building
should have and how it will
be constructed.
Each can be made of different
There are several kinds of roofs.
and each has advantages
and disadvantages,
depending
materials,
on the climate,
the builders'
budget,
the availability
of
materials,
and the ease of construction.
To make a good decision
about the kind of roof to be used, the builder
needs to know:
. the basic roof styles;
for the local climate

their
advantages
and environment;

. the kinds of materials
for each roof style;
0 how to design
roof style.
Roof

Styles

and

suitable

and build

Their

and disadvantages

each

Functions

All roofs provide protection
from
the el?Fiii?nts: sun, rain,
wind, dust,
heat, cold, and animals and insects.
But each different
kind of roof
protects
against
some things better
than others.
In addition
the
different
roof styles
vary in
their
durability
and ease of
construction.
There

are

@flat:

across
walls;
. shed:

angle,

four

basic

roof

FLAT ROOF

styles:

the roof simply
lies flat
the top of the building's
SHED ROOF

the roof is built
at a slight
generally
from lo-30".

the roof
a triangle
over the building,
dabie
roofs are a combination
of
each starting
from
two shed roofs,
the opposite
sides of the building
with the same angle or pitch,
hence, "double-pitched";

hipped: hipped roofs are gable
roofs that have been pitched
on the ends of the building
as well as the sides.

HI P!‘ED ROOF

gabZe or double-pitched:

forms

FLAT ROOFS
Flat roofs are generally
the most
difficult
to build and the least
suitable
of roof styles,
especially
in buildings
wider than 4-5 m.
Here are some of their
disadvantages:

principal

. because they are flat
they tend
to sag in the middle unless
given very strong support:
the most common forms of
support,
wooden or reinforced
concrete
beams, must be heavy
to be strong:
as a result
they are difficult
to lift
into place;
reinforced
concrete
or heavy woodcotwmrs may also
be used to support flat
roofs.
However, columns reduce usable
space inside
the building;
. flat
roofs tend to hold snow or
rain;
this increases
the weight
on the beams and walls and leads
to leaks and warping;
. flat
roofs tend to lift
in wind
and must be securely
tied to
the building;
in areas with
severe storms,
flat
roofs
are dangerous.
The only advantage of flat
roofs is
that they can provide extra living
space above buildings
in dry,
desert-like
areas.

GABLE ROOF

10 3

SHED ROOFS
Shed roofs are generally
easier to
They are
support than flat
roofs.
usually
the least expensive
and
the easiest
style of roof to
build.
Because of their
pitch
(angle),
they shed water easily
and are
particularly
good in warm, rainy
climates
with no snow.
Shed roofs are slightly
less
subject
to wind pressure
than
However, in stormy
flat
roofs.
areas they must still
be very
securely
tied down to the walls.
G-ABLE ROOFS
Gable roofs use more materials,
require
more care in design,
and
are more expensive
than shed roofs.
over
However, they can be built
large areas (buildings
over 10 m.
wide) without
heavy beam or column
support because they are made of
relatively
light
materials
and
are extremely
strong.
Gable roofs are much less affected
by wind than flat or shed roofs
and are therefore
better-suited
to
areas with strong
storms.

In addition,
gable roofs provide
excellent
insulation
against
heat
In areas with cold
and cold.
nights
or seasons, the triangle
formed by the double pitch above
the ceiling
helps hold the heat in
In very hot areas, gable
at night.
roofs that are ventilated
have the
opposite
effect:
they pass heat
out of the building
quickly,
thus helping
to keep it cool.
gable roofs are the
In general,
best, and most adaptable
style
whenever they are within,the
builder's
budget.
HIPPED RtiFS
Hipped roofs provide
more protection
auainst
wind on the ends of a
b&.lding
than do gable roofs.
But this is their
only advantage
Hipped
over the other roof styles.
roofs are harder to design,
harder
to construct
and use more
materials
than any other roof
style.
Roof

Materials

Roof materials
for the frame
covering.

fall
into two categories:
and those that
and support,

those that are used
are used as the roof

WOOD
Wood is
because
material
practical

the most common material
used for roof frames and supports
When the covering
it is strong and easy to work with.
will
be heavy (tile,
for example),
wood may be the onZy
material
for the frame and support of the roof.

before planning
to build
a wood frame, or to use wood
One caution:
make sure th,at wood is available
in
beams for roof-support,
Wood
beams
must
be
at
least
5 x 15
sufficient
quantity
and size.
cm., and wood used in frame construction
should be at least 5 x
10 cm. To estimate
the quantities
of wood needed for any roof
design,
see pages 107-114 on roof construction
plans.

105

BAMBOO
Bamboo is an excellent
frame
especially
where resistance
material,
to wind and earthquake
are important
It is light,
flexible,
concerns.
and strong.
Where large species of bamboo
are available,
they, zan be cut
to make tiles
for a roof
covering.
The chief
are:

disadvantages

of bamboo

nailed:
a it cannot be easily
most connections
are made by
tying section
together
with
wire,
or hemp lashings;
thongs,
. it tends to rot when exposed
dampness or rain.

MUD
Mud is the least expensive
roof covering,
disadvantages:
it is very heavy; it tends
cause leaks,and
it requires
very frequent
collapse.

but it has serious
to develop cracks that
repairs
to prevent

106
TILE
Tile roof coverings
are also very
heavy.
The materials
and labor
involved
make tile
very expensive.
Tile roofs should not be used in
earthquake
zones.
REINFORCED CONCRETE
This kind of roof is seldom needed
If it is
on small buildings.
an
engineer
must be
required,
consulted
on its design.
CORRUGATEDMETAL OR ASBESTOS
Corrugated
iron,
aluminum,
zinc
and asbestos
sheets have several
advantages
as roof coverings:
. they are
. they are
or gable
. they are
. they are
. aluminum
On the other
disadvantages,
roofs:

very light;
easy to use on shed
roofs;
usually
leak-free;
relatively
fireproof;
sheets are rust-free.
hand, they
especially

have some
on flat

. they are cold in winter
and hot
in the summer;
. they rust (except for asbestos
and aluminum);
. they are noisy during rain;
. they tend to tear away easily
during heavy storms or wind;
. asbestos has been identified
as a possible
cause of cancer.
THATCH
Thatch is an effective
and
inexpensive
covering
for wood
It is light.
or bamboo frames.
it
provides
better
In addition,
insulation
against
heat and it is
However, thatch
quieter
than metal..
will
not last as long as other roof
especially
in wet
coverings,
It is also easily
climates.
infested
by animals and insects
unless treated
with an effective
insecticide.

Construction

Details

for

Roofs

FIAT ROOFS
Flat

roofs

are built

in three

major

steps:

S!l’EP I:

Placement of the beams across the width of the building:
Wood beams should be about 5cm x 15cm.
If bamboo is used
beams should be made from the thickest
stalks
available.
For heavy materials
such as tile.
place the beams at
least every 0.6 -- l.Om. For lighter
covering
materials,
the beams can be slightly
further
apart if desired.
Each
beam should be as long as the building
is wide plus the
length of overhang on both sides of the building.

S!TEP2:

Place purlins
across the beams:
Purlins
are horizontal
pieces of a roof frame that support either
the roof
covering
material
(in flat
and shed roofs),
or the
pitched
rafters
(in a gabled or hipped roof).
Each
purlin
should be as long as the building
plus the length
of overhang on both ends of the building.

STEP 3: Cover the roof with the planned
bolting,
nailing,
or lashing
it

covering
securely

material,
tying,
to the purlins.

108

SHED ROOFS
Shed roofs can be built
in two ways.
Either wayr the beams for support
can be both thinner
and further
apart than for flat
roofs:
. If one wall going the length
of the building
is higher than
the shed roof can be
the other,
built
with beam supports
like
flat
roofs;

S I MPLE BEAM SUPPORTED
SHED ROOF

A much stronger
shed roof can be
built
if the building
walls are
Beams are laid across
level.
Then pitched
rafters
the walls.
made of 5 x 10 cm. wood planks
are supported
at an angle by
Finally,
the
four struts.
purlins
are attached
as in the
flat roof and the covering
material
is tied to the
purlins:
TRUSS SUPPORTED SHED ROOF

LO9

GABLE (DOUBLE-PITCHED) ROOFS
Gable roofs are supported
by
light
weight wood, bamboo, or
steel structures
called
trusses.
Basically
trusses
are triangular
shapes strengthened
by struts
that help distribute
the weight of
the roof and the force of wind,
rain,
snow, and earthquake
evenly.
The illustrations
on this page and
the next show how trusses
are used
and identify
their
key parts.
See
the glossary
on the next page for
definitions
of each part.

GABLE ROOF: WITH PURLINS ATTACHED TO TRUSSES,
AND USING END WALLS AS TRUSS SUPPORTS

110

GLOSSARY OF TERMS FOR GABLED‘ROOFS AND TRUSSES
Abeam pladed horizontally
across the width of the
building
and tied to the walls on each end.
The cross
tie is the bottom part of a truss-triangle.
2. Eczve:
The part of a roof that overhangs the wall.
3. PurZh:
Horizontal
beams that tie the trusses
together.
(Not shown)
4. Rafter:
Either
of the angled parts of the truss.
5. RQfteP Batten:
A short beam that joins
the top of the rafters
in
a truss.
6. Rafter hzcketr
A short beam that supports
the rafter
when
there is a large overhang.
7. Ridge:
The top point of the truss
(also czlled
the cqxx).
8. SpZke:
A section
in a rafter
where two long pieces of
wood are joined
together
with nails
and a short
piece of wood.
9. strut:
Any short beam attached
to the cross tie and rafters
of the truss and used to provide
strength.
10. mss :
One of several
triangular
support-structures
used
to hold up a gabled roof.
11. WQZZ
Phzte: The part of the wall to which the roof frame is
attached.
1.

Cross ITie:

111

Sample Truss

Plans

The following
pages show the plans
a gabled roof.
The first
plan
(20-32 feet in
buildings
up to
In either
case,

for

two different

is for roofs on buildings
6 to 9.6 meters wide
U.S. measurements).
The second plan is for
6 'meters wide (18 feet in U.S. measurements).
the trusses
should be placed 2 meters apart.

The charts
accompanying
each plan indicate
the
part of the truss for any given building
width.
Note:

trusses

length

of each

The charts were originally
prepared
in U.S. measures.
Field workers in areas using metric
measures should try
to find similar
charts and plans in their
local
area,
If metric
since standard lengths
may not be comparable.
the charts printed
here may be
. charts
are unavailable,
used.

for

TRUSS PLAN FOR BUILDINGS

BUILDING
WIDTH,
Meters

6 -

9.6

ESTIMATING LENGTH
OF MEMBER,
Meters

METERS WIDE

CONSTRUCTION
Distance
Between
Bolt
Connections

6.0

3.75

4.38

2.32

1.25

2.10

1.83

2.11

1.05

6.6

4.05

4.72

2.52

1.35

2.30

2.00

2.31

1.15

7.2

4.35

5.05

2.75

1.45

2.50

2.16

2.51

1.25

7.8

4.65

5.40

2.95

1.55

2.70

2.34

2.71

1.35

8.4

4.95

5.80

3.15

1.65

2.90

2.52

2.91

1.45

5.25

6.10

3.35

1.75

3.10

2.69

3.11

1.55

5.55

6.45

3.55

1.85

3.30

2.87

3.31

1.65

9.6

113

114

UP TO 6 METERS WIDE

TRUSS PLAN FOR BUILDINGS

1 3/4"

BOLT

6" Lona

PURLINS

ROSS 7-I C

BOLT
Long
BOLT

RING BEAM
UUNU

I.-.

l5tHM

4" LONG
3”

. .

EUILhNG
WIDTH,
Meters

ESTIMATING LENGTH
OF MEMBER,
Meters:
i

IB‘.

BOLT/M. S. ROD

JhSTRUCT
I ON
Distance
Between
Bolg Connect ions
I
c

3.3

1.16

2.29

1.33

2.65

3.6,

4.35

1.30

2.85

4.2

4.95

! 47:

3.20:.

4.5

4.8“

5.55

..:5

3
.,:i>

:
I

1.51

2.99

6.15

f 52.

s:90

5.7

1.67

3.35

\‘:,..

_::. .-. \
/

DlRECTlONS

FOR

CONSTRUCTION

Once the construction
plans
construction
can begin.

for

the entire

building

are complete,

This section
is designed to help the field
worker and community
member(s) organize
their
work to make the construction
process
and to provide
step-by-step
directions
for the
flow smoothly,
critical
parts of construction
that are common to all buildings.
The material

is divided

into

six

parts:

. SETTING OUT (LAYING OUT)
. FOUNDATION FOOTINGS
. FOUNDATION WALLS
. FLOORS
. WALLS, WINDOWS, AND DOORS

SETTING

QUT

ClAV!~G

tX.JT)

In order to begin digging
the
trenches
required
for a building's
the builder
must first
foundation,
transfer
the lines and measurements
indicated
on his or her foundation
That is,
plan to the building
site.
the exact length,
width,
depth, and
position
of the foundation
trenches
must be marked on the ground.
This movement from the plan to the
actual
site is called
setting
out.
It is probably
the most critical
step in the entire
construction
process.

FLOOR PLAN

117
A building
accurately

that
will

is set
be:

out

o level: no part of the floor
or
foundation
higher than
another;

THIS

r----

square:

walls parallel
same length;

and the

~plumb: straight
up and down, not
leaning
to one side or
the other
NOT THIS

THIS

>THlS
_____

-___---.

118

A building
that is set out
carelessly
will
be difficult
or
impossible
to construct
according
the finished
to plan.
As a result,
structure
may be expensive
to
So it is
maintain
and unhealthful.
important
to take special
care when
setting
out.
There are three
setting
out:
.Orientation

the site;

major

steps

of the building

.MzrkGzg a simple outline
building's
foundation
ground;
l

to
on

of the
on the

"batter
boards" aromd
the foundation
outline
and
marking the position
of inside
walls,
doors, and windows on the
boards.

PZacing

TAPE MEASURE

The tools shown on this page are
needed to set out a building
so that
it will
be level,
square, and
accurately
measured.

PLUMB BOB

LEVEL

BOARDS
(5cm x 1Ocm x 1.5m)

NAILS

I-

119
Orientation

The orientation
of a building
is the
direction
its front walls face:
north,
east, south, west or
something
in between.
To mark the orientation
on the site,
This is easiest
first
find north.
But if no compass
with a compass.
finding
north is still
is available,
fairly
simple.
The builder
should stand at the
building
position
so that his/her
right
arm points
at the spot where
the sun rose in the morning while
the left
arm points
to where the sun
set the last night.
In this position
the builder
will
be facing north.

SUNSET ,
1 I

Standing in the same position,
if the
builder
moves his/her
arms so they
form a straight
line to the sides,
they will
be pointing
due west (left
arm) and east (right
arm).
Once the main compass points
have
been established,
use a stick
to mark
out the shape and position
of the
Add about 2 meters to the
building.
dimensions
of the building
on all
sides:
the extra space will
be needed
for supplies
and work space during
construction.

Next, clear the ground inside
this
area of trees,
shrubs, and loose
If the topsoil
is
plant growth.
loose, clear away the top 15cm or so Y
to get down to hard earth:
loose soil
will
not support a building.
the lan d at the positi
If clearinq
outlined
proves too difficult,
or
if it would require
felling
trees
that are desired
for their
shade or
consider
moving the building
beauty,
a short distance
before clearing
the
land.

PROXIMATE

BUILD;

120
iMarking

the

Fsundatiosa

Qutline

The next step is to mark the outline
of the foundation
on the site using
string
and pegs.
Three measures

are very

important:

* the length of .each wall
marked exactly:
* the

string

* the corners
90°
exactly

must be

must be exactly

level;

must be square:

CORRECT

of each wall
is easy to set
Simply measure
out on level ground.
it with a tape measure, making sure
to pull the measure tight.

The length

INCORRE’;T : NOT ACCURATE J

When the site is onwzevenground,
care must be taken to measure the
length of the wall along a level
line:
following
the slope of the
ground will
throw off the measurements.

121

To prevent

errors,
begin at the
highest
end of the first
wall's
length and attach the string
to a
peg planted
at the end-point.
Set
a new peg every 2 meters to prevent
the string
from sagging,
and test to
make sure the string
is level by
using a plumb bob and mason's square
as shown: when the plumb bob stops
swinging
it will
be plumb (straight
will
be
up and down); the string
exactly
level when it is a 90° to
the bob string.
Repeat this process until
the
length of string
set out is equal
to the planned length of the first
wall.

-----MB

If the ground is sloped
very steeply,
it may be
easier and more accurate
to measure the wall's
length in steps or
stages.
To do this run
a new length of string
from the bottom of every
second peg (that is,
every 4 meters).
Test
with a plumb bob to be
sure that every peg is
straight
up and down.
In addition,
to be sure
there are no gaps or
.overlaps
in the measurement of each new stager
piant a small block with
a circle
on it right
next to every other peg:
then in measuring
the
next stage (or step)
along the wall,
hold the
tape measure to the point
in the circle
that marks
the end of the last stage.

BOB

Once the first
wall has been set out
the second wall should be set out at
right
angles to it (900).
There are
several ways to make sure that this
angle, and the angles between all th
walls set out are square:
s

A mason's square is good for
distances
up to 3 meters.
Use it
to get started,
but don't use it
to check the entire
outline.

. One of the easiest
and most
accurate methods of checking
large
distances
for squareness
is to
compare the diagonals.
Simply
measure the diagonal
lines
from
Opposite corners of the foundation
When they are exactly
equal in
length,
all the angles will
be 90°
On uneven ground, be sure to use
the tape measure along a level
line!
. If measuring
the diagonals
is
inconvenient,
or if the building
is not a simple rectangle,
another
method is the 3-4-5 calculation:
If the wali on one side of a
right
angle is 3 units
long
and the wall on the other side
is 4 units
long, a-line
drawn
between their
ends wit2 always be
5 units long. Here's how to use
this rule to test whether the
angle between two walls
is
square:
Along the string
set
out for one wall,
measure and
mark off 1.5 meters (3 x .5m).
Then, along the string
set out
for the second wall,
measure and
mark off 2 meters (4 x .5m).
Next, measure and cut a piece of
string
2.5 meters long (5 x .5m)
and hold its ends to the Faints
marked off along each wall.
When the 2.5 meter string
just
touches both marks with no slack
left
over, the angle between the
two wall strings
will
be exactly
square.
If the 2.5 meter string
is too short or long, adjust
either
one of the wall strings
Until
it fits
exactly.

TRI ANGLE

123
:-KING

THE INSIDE FOUNDATION LINES

Once the outside
walls of the
.foundation
have been set out with
pegs and string,
the next step is
to set out a second set of lines to
mark the inside of the foundation
walls.
Use the same procedures
to
keep them level,
accurate
in length,
and square.
The easiest
way to begin is to
measure the width of the foundation
wall and mark it along the strings
set out for two opposite
walls.
Then set out a string
between these
two points
and fasten the ends with
Use
a plumb bob to be sure
pegs.
each peg is directly
beneath the
outside
foundation
line.
Next,
of the
peg at
lines
corners
Batter

repeat this process for each
remaining
walls.
Place a
every point where the new
cross:
these are the inside
of the foundation
walls.
Boards

Batter boards are like a single
rail
fence placed around the building
position.
They should be placed
after
the foundation
lines have been
set out and before any digging
for
construction
begins.
Batter boards
are essential
for two reasons:
. They provide
permanent
points
for the position
foundation
walls:
these
needed once the string
have been removed during
construction;
l

reference
of the
will
be
markings

They can be used to measure and
mark off the exact position
of
doors, windows, and floors,
thus
making it much easier
to build the
walls accurately.

To be useful,
batter
boards must be
exactly
and should be set
about 1 meter back from the string
marking the outside
foundation
line.
le\rei

124

PLACING BATTER BOARDS
To place batter
boards around the
building
postion,
first
find the
highest
point on the site about
1 meter outside
the outer foundation
line and place a wooden stake firmly
in the ground.
Nail the first
board to this stake
so that the top of the board is at
least as high as the top of the
foundation
walls will
be.
Since the
foundation
walls must be as high as
the floor,
this will
be at least
20-30cm.
above the ground.
place a second stake 2 meters
from the first
and 1 meter outside
the outer foundation
line.
When this
stake is secure, nail the other end
of the first
batter
board to it,
taking care that the batter
board is
level.
Nail a second board to this
same stake and repeat the process of
placing
new stakes,
levelling,
and
nailing
the boards, until
the batter
boards form a fence that goes
completely
around the -building
position.
Next,

AS THE PLANNED

125
HOW TO LEVEL BAT':,'? BOARDS
A commercially
made "spirit
level"
is the easiest
levelling
device to
use.
Place it on the surface
- in
this case the top edge of the
batter
board - and keep adjusting
the height
of the board at the
opposite
end until
the bubble is
in the center.

When joining
boards at stakes,
place the level over the seam
board to maintain
a continuous
line.

of the
level

An additional
check on level can be
made at the corners:
use an extra
board to provide a surface
for the
level.

Another method is to use a water
level:
this is a clear plastic
hose
that is filled
with water.
Adjust
the first
end of the hose to a known
level mark.
When the other end of
the hose is placed at the next stake,
the water inside will
be at the same
level as at the first
end.
To
prevent spillage
the ends may be
plugged until
the hose is in position.
But all plugs must be removed to get
an accurate
measurement.

SPIRIT LEVEL
When Air Bubble
is Between the
Hair1 ines
the
Boards ar; Level

TRANSFERRING MARKS TO BATTER BOARDS
Once the batter
boards are complete,
all the measurements shown on the
written
foundation
plans should be
marked on the boards.
First,
transfer
the foundation
lines
marked by the strings
set out
earlier:
run a strinq
from one board
to the opposite
board directly
over
each foundation
line.
Use a plumb
bob to make sure this new string
is
over the corner pegs.

Next I place nails or saw cuts
tops of the boards where they
sect the strings.

in the
inter-

A'good system is to use different
marks for the foundation
lines than
those to be used for other
important
measures such as wall lines
and the positions
of doo::s and
windows.
For example, use small
notches cut with a saw to indicate
the foundation
lines.
Then use nails
to indicate
the wall lines.
Once the foundation
lines and *:lall
lines have been marked on the batter
boards, the builder
is ready to
start
digging
the foundation
trenches.
Note: the digging
will
be easier if
the strings
are left
in place until
the trenches
have been well started.

127

CONSTRWCTIQN
Digging

the

OF FOUNBATlON
Foundation

FOOTINGS

Trench

Before the concrete
footing
can be poured, the builder
must dig a
trench for it.
The depth of the trench depends on characteristics
of the site and building
that should have been determined
in the
basic planning
stage (see pages 82-88).
However, the width of the trench,
and the care with
be dug depend on whether the concrete
footing
will
directly
in the trench or into wooden forms.

which it must
be poured

TRENCHES FOR FOOTINGS POURED WITHOUT FORMS
When wooden forms will
not be used,
the trenches
must be dug very
carefully:
. the walls of the trench must be
plumb (straight
up and down);
the earth forming the trench
walls and bottom must be very
firm so that there is no danger
of the trench crumbling
when the
concrete
is poured:

. the earth must be removed
carefully
so that the earth at
the bottom of the trench is
smooth, clear of all trash or
debris,
and undisturbed
(undisturbed
means that the
earth has not been moved,
loosened,
or dislodged
by the
digging);

)

. the bottom of the trench must be
absolutely
level:
6-8 measurements
with a straight
board and level
should be made along the length of
the trench to be certain
of the
level;
0

the trench must be exactly
as
wide as the concrete
footing;

. the trench must be free
standing
water.

UND I

RI GHT

128
TRENCHES FOR FOOTINGS POURED WITH FORMS
It is much more common to use wooden
forms when pouring the concrete
footing
because the ground at
building
sites
is rarely
hard enough
to stay in place when the concrete
is poured directly
in the trench.
Like the trenches
trenches
footings,
will
be used must
bottom, and hard.
bottom must also
clear of debris,

for non-form
in which forms
be level at the
The earth at the
be left
smooth,
and undisturbed.

However, there is no need to make the
side walls of the trench plumb.
The
only requirement
is that the trench
be 30-45 centimeters
wider than the
footing
will
be, so that the:e will
be room in the trench for the wooden
forms and work space for the builders.
A FINAL NOTE ON DIGGING TRENCHES
When digging
the trenches,
any loose
soil,
or soil with organic material
should be shovelled
outstie
the
foundation
lines and discarded.
Hard earth that is dug up should be
spread evenly &side the foundation
lines:
it will
be very useful
as
part of the fill
under the floor.
Organic

E Loose

Soil

129

Formwork

for

Footings

The formwork should be made of boards measuring about 5cm x 15cm
or 5cm x 30cm.
The boards should be supported
by 5cm x lOcm
braces called
studs.
Allow about twice the width of the footing
between the studs (but never more than 1.3 - 1.6 meters);
the
formwork must be strong because concrete
weighs 2.5 metric
tons
per cubic meter.
Tight
Joints
to Prevent
Leaks

In addition:
*

the joints
and corners of the formwork must be tight:
neither
the concrete,
nor the water should be able to leak out.
If
water leaks out it will
weaken the mixture;
the walls of the forms must be exactly
plumb (straight
down), and the tops of the forms must be level:
any
inaccuracies
will
weaken the foundation;

up and

. small boards, called
spacers,
should be nailed
to the tops
of the formwork to keep the sides of the forms from leaning
toward each other before the concrete
is poured;
. the formwork should be built
so that it may be removed easily
without
damage: most forms can be re-used;
l

if part of the footing
will
be visible
and the builder
would
like its surface to be smooth, the boards of the formwork
must also be smooth: .any irregularities
in the wood - burrs,
bends, chips,
and so on - will
leave an impression
in the
concrete,

130
FORMWORKFOR A STEPPED FOUNDATION
The formwork for a stepped foundation
is constructed
in the same manner
However, if the
described
above.
walls will
be made of block or brick,
the height
of each step of the
footing
must be equal to the
height of the blocks used, or to a
whole number multiple
of their
height.
For example, if the blocks
used in the foundation
are 20cm high,
then the steps must be 20cm or 40cm
or 60cm high, and so on.

Making

the

To prepare

Concrete

a strong,

for

Foundatisn

durable

Footings

concrete

. select,
prepare,
and store
sand, gravel)
properly;

the

mixture#
ingredients

. use proportions
of these ingredients
suitable
for his or her purpose;
l

mix the ingredients
water.

properly

the builder

with

that

must:

(cement,
are

each other

and with

SELECTING INGREDIENTS
Cement
The commercial
cement most commonly used for l-story
buildings
is
Portland
cement.
It is available
from most manufacturers.
Portland
cement, and most locally
made limestone
cements, can
be stored for up to 6 months in a cool,
shaded,*,
area.
If the
cement has hard lumps that are difficult
to break or crumble,
don:t use it.
In humid tropical
areas, or areas with heavy rainfall,
it may be
advisable
to purchase "hydrophobic"
cement, since this kind of
cement can be stored in damp conditions
for long periods
of time.

131
Sand
The sand is possibly
the most
important
ingredient
in the
concrete
mix, since it provides
most
of the plasticity:
that is, it makes
the mixture
easy to work with.
There should never be more than 3
parts sand for every 1 part cement.
TOOZittZe sand in a mixture
may result
in shrinkage
cracks when the concrete
dries;
too much sand will
produce a
harsh mortar that will
be difficult
to work with and may lead to leaks.
Never use sand from the ocean: the
grains in ocean sand are too uniform
in size and will
not make a useful
concrete.
Any other source of sand
But it is crucial
that the
is fine.
sand used be clean.
To test whether
to be -used:
. put
fill

sand is clean

5cm of sand in a jar
the jar with water:

enough
and

WATER
SAND b

. shake the jar vigorously
for
1 minute and let it stand for
1 hour.
The layer of dirt
that
settles
on top of the sand
should be less than 6mm thick.
If it is more, wash the sand or
find other sand (but again, do
not use ocean sand).
SAND: SHOULD BE LESS
THAN 6 mm THICK

Gravel
Gravel adds strength
to concrete
because it increases
the range
grain sixes in the mixture.
Generally
it is also the easiest
ingredient
to find and prepare locally.
Gravel

247-201

should

0 - 71 - 10

be clean,

and should

range

in size

from

6-18mm.

132
MIXING THE BEST PROPORTIONS OF INGREDIENTS
The concrete
mixture
required
for a foundation
footing
may be
very different
from the mixture
needed for concrete
used for
another purpose.
the average mixture
for foundation
For example,
1:2 3/4: 4 (that is, 1 part cement, 2 3/4 parts
parts gravel).

footings
is
sand, and 4

The higher
But a typical
mixture
for fence posts is l:l:l&.
proportions
of sand and gravel in the footing
mixture
provide
Since fence posts
maximum strength
and resistance
to water.
do not need to be as strong or as water resistant
as footings,
mixture.
they can be made of a weaker and less expensive
Table 4 in Appendix 5 recommends average mixtures
for different
Following
these recommendations
will
assure
uses of concrete.
to their
needs.
builders
that their
concrete
will
be well-suited

M3CXIBTG
PROCEDURE
Mixing

Area

Concrete should be mixed on a flat
surface that will
not absorb water.
Mix it on a wooden platform
about
Or, mix it
2 meters by 2 meters.
on a cement-sand
platform.
Cement-sand platforms
must be made
a week before concrete
can be mixed
on them.
To build a platform,
mix
cement and sand on the ground in a
1:6 ratio,
cement to 'sand.
Add
water,
and spread the mixture
in a
circle
about 2 meters in diameter.

133
Choosing

A Measuring

Unit

Since the dry ingredients
‘of concrete,
cement, sand, and gravel,
are mixed by
the
easiest
way
to
be sure
volume,
that the proportions
are right
is to
decide on a standard measuring unit
such as a box or wheelbarrow.
Once the
it to the
ingredient
make the
foundation
each unit
of sand,

unit is chosen, simply fill
appropriate
level with each
in turn.
For example, to
recommended mix for
footings,
1:2 3/4; 4, for
of cement, add 2 3/4 units
and 4 units of gravel.

Generally,
the easiest
measuringunit
to use is a gauge box or wheelbarrow
that holds 1 bag of cement.
The box
or wheelbarrow
should be approximately
40cm x 4(?cm x 40cm. Note: to avoid
confusion,
once the size of the
measuring unit has been chosen, do
not use different
size boxes or
wheelbarrows
on the site for any
purpose.
When using

a box:

. the box should have handles
on both sides for easy lifting
by two people;
. if the materials
are close
enough to the platform
so that
they do not have to be carried,
it is easier to use a bottomless
box: set the box directly
on the
mixing platform
and fill
it to
measure; then, lift
it up to
empty the ingredients
into the
mixture.
Mixing

the

Ingredients

The ingredients
always be mixed
FIRST, spread

in concrete
should
in the same order:

the correct
amount of
sand on the platform
with a shovel.

GAUGEBOX

4
SECOND, dump the required
amount of
cement on the sand, and mix the
sand and cement until
the color of
the pile is uniform:
there should
be no streaks
of color.

THIRD, add the required
amount of
gravel and mix it with the sand
and cement until
the gravel is
thoroughly
distributed
and there
are no streaks
of color.

FOURTH, hollow
out a hole in the
center of the.mix.
Add water
slowly,
pushing the ingredients
toward the center while turning
them over with a shovel.

135
A good test
of water is

for the correct
amount
to walk on the mixture:

a if you sink to your ankles or
there is too much water;
higher,
a if you sink about 5-6cm,
have the right
mixture.

you

The correct
amount of water is
important
because too much or too
little
will
weaken the mixture:

CORRECT AMOUNT OF WATER

- if there is too little
water,
air spaces (weak spots) will
form
in the concrete;
- if there is too much water:
a
cement-water
paste will
rise to
weakening the
the surface,
mixture
underneath.
Pouring

Concrete

for

Foundation

Fresh concrete
mix has
carried
to the footing
water-tight
containers
wheelbarrows:
no water
seep out of the mixture:

to be
trench in
such as
should

the mix sh.Duld be poured
within
45 minutes-of
mixing;

Footings

avoid b:;mps during transport
from the mixing area to the
site:
vibration
will
cause
the aggregates
(sand and
gravel)
to separate
from
the mixture;
it is
flow
drop
sand

best to let the mix
into the trench;
do not
it into place or the
and gravel may begin separating

from the

mixture;

. once in place,
a shovel,
rod,

the concrete
should be worked up and down with
or spading tool to break air pockets;

. footings
footings

30cm

up to
should

deep can be poured all
be poured in layers
15-30cm

once started,
the pouring must be continuous:
has started
to set crmnot be disturbed;

at once; deeper
deep at a time;
concrete

that

if you must stop pouring at the end of a day,
stop at the end of the poured section;

place

a vertical

when pouring is resumed, roughen the edge of the old section
and paint it with a cement-water
paste before applying
fresh
(Use a stick or any sharp object
to roughen the
concrete.
old section).

Curing

Concrete

Footings

As concrete
hardens,
the water in the mix gradually
evaporates.
Prolonging
that process increases
the strength
and watertightness
of concrete.
Immediately
after the concrete
has set , put a wet covering
over
The covering
may be made with wet burlap bags, or a thin
layer of wet sand, or uet straw.
The covering
should be
sprinkled
with water 2 or 3 times a day for at least
7 days.
.I.

Reinforced

Footings

Reinforced
concrete
footings
require
the same formwork as
unreinforced
footings
(see page 129). Steel rods are attached
to
the form before pouring.
The rods should be made of steel about
9mm in diameter.
They must be cleat
---= free of rust.
When placing

the rods:

. 'Jse steel wire to hold them in place 2.5-5cm above the bottom
of the trench,
and 5-7.5cm from the sides of the forms.
Temporary wood supports
may be used while the steel wire is
being tied in place,' but they must be removed before pouring
concrete.
'

Plain
(bars
straight

round bars must be hooked at the ends; deformed bars
with curved ridqes along their
surface)
can be left
since their
ridges will
hold the concrete
firmly.

. The ends of bars should be
spliced
(overlapped)
for a
the
length at Zeast 30times
diameter
of the rods.
For
example, 9mm rods should
overlap
for 2.7 meters.
e The rods must be complett_ly
surrounded
by concrete,
and
the concrete
and steel must
be fuZZy and tightly
bonded
to work properly;
any
exposed steel will
rust
through,
and this will
weaken the steel and
destroy
the bond.

PLAIN

ROUNP DAc

“DEFORMED”

BAR

The recommended concrete
footings
is 1:2&:4.
Footings
section

mixture

may also be reinforced
on Bamboo, page 188.

CONSTFBUCTION

OF THE

for
with

reinforced
bamboo.

FOUNDATION

foundation
See the separate

WALLS

.Once the foundation
footing.is
complete,
construction
of the
foundation
walls can begin.
The foundation
walls may be made of
concrete,
or anyofthe
blocks made with cement (Sand-Cement,
Stabilized
Earth).
Adobe blocks should never be used for a
foundation.
The foundation
walls should be built
so that the top of the
foundation
is exactly
level with the floor
height
(at least
lo-30cm above the ground at the highest
point on the building
site).
Concrete

Fowndation

Wafls

MIXTURE
The best concrete
mixture
for foundation
proportions
as the concrete
for footings:

walls has the
1:2 3/4 :4.

same

FORMWORX
The best formwork to use for concrete
foundation
walls isre-usable
unit formwork.
Since each "unit"
can be used over and over again,
the cost of the wood for the formwork can be shared by an entire
community.

139
ASPREADER!

Typical

form units

. 2.5 meters

are:

long;

. either
60cm or 120cm high,
foundation
~311s;
4 made of boards
l

supported

about

by braces

depending

2.5cm x
about

bolted
together,
not nailed
to assemble and disassemble.

on the height

of the

15cm;

5cm x 10cm;
(Bolts make the units
They also make the

much easier
forms tighter.).

Before concrete
is poured,the
walls of each unit should be kept
apart by 2.5cm x 1Ocm spreaders.
Spreaders can be removed as the
concrete
is poured, since the concrete
weighs enough to keep the
forms apart.
After the concrete
is poured the walls of the unit-should
be held
together
by 5cm x 1Ocm spacers.
Spacers and spreaders
should be
placed at 1.5 meter intervals.
POURING CONCRETE FOR FOUNDATION WALLS
Concrete for
for footings
layers 15-30
walls before
walls should
time.

foundation
walls should be mixed just as the concrete
(see pages 130-136).c It should then be poured in
centimeters
deep.
Pour the first
layer
for a22 the
going on to the second layer.
All the foundation
be built
up together,
rather
than one wall at a

it is best
If possible,
this
one day's pouring:
If it is
surface
it with
surface.
when the

to complete all the foundation
walls
will
avoid seams in the concrete.

necessary to stop before completion
of the walls,
the top
of the last layer poured should be roughened by scratching
a stick or placing
large pebbles that project
out of the
This will
provide
a good "grip"
for the fresh concrete
pouring resumes.

CURING
In warm weather,
the forms can be removed after
3 days; in cold
weather,
leave them on at least a week and preferably
10 days.
As with footings,
cover the surfaces
of all concrete
foundation
walls for at least a week with wet sand, straw, or burlap.

Block

Founciation

Construction

Walls

of a block

a Making

the blocks:

. Laying

the blocks;

. Finishing
Making

foundation

wall

requires

3 basic

steps:

the Mortar.

Blocks

There are three types of block suitable
for foundation
walls:
concrete
blocks,
sand-cement blocks,
and stabilized
earth blocks
lnot adobe).
Each-requires
different
procedures
and ingredients.
MAKING CONCRETE BLOCKS
Ingredients
The ingredients
required
for
concrete
blocks are cement, sand,
and gravel
in a 1:2:4 mix.
The
concrete
is mixed using the method
described
on page .132-136.
Forms
The most commonnomina2 size of
concrete
blocks is 20cm x 20cm x 40cm.

141
The nominal size of a block is the acttta2 size of the block + the
thickness
of mortar in which it will
be set.
Planning
for 5mm cf
mortar between blocks,
this means the actual
size of the most
common concrete
block is'19.5cm
x 19.5cm x 39.5cm.
Thus, the
forms used for these blocks should measure 19.5cm x 19.5cm x 39.5cm
on the inside.
The forms should be made of wood 2.5cm thick,
(or dowels) to create holes in the block.

with

removable

cores

Procedure
The mixture
should have enough water to make the mix plastic
but
not watery.
The mix is placed in the form and hand-spaded
or
vibrated
mechanically
to remove air pockets.
If the mix is spaded, the forms should
12 hours (or 2-3 days in cold weather).
mechanically,
the forms may be removed

not be removed for at least
If the mix is vibrated
30 seconds after
vibration.

The cores should be removed first:
tap them gently
out slowly.
Then slowly
remove the outside
form.
the corners
and edges.

and pull them
Avoid breaking

The blocks should be kept damp for 7-10 days and should
sheltered
from wind and sun for 28 days before use.

MAKING SAND-CEMENT BLOCKS
Inaredients
The usual mixture
of cement-to-sand
'for sand-cement
blocks is 1:6.
A
mixture
of 1:8 can be used for block
walls that will
not carry roof loads,
but this is not sufficient
for
foundation
walls.
The best sand is clean river-bed
sand composed of many different
size
particles.
If it is dirty,
the sand
should be washed, or sifted
through
a fine screen (4-5mm square),
since
dirt will
weaken the blocks.
Do not
use ocean sand.
M_ixing Site
The site for making sand-cement blocks should be flat
and shaded:
if the blocks rest on an une-ven surface,
they will
crack before
they harden; and direct
sun will
dry blocks out before they can
cure properly.
If the mixing site mustbe in the open sun, the
blocks should be moved to a flat,
shaded area for curing.

142
Mixing
Following
the mixing procedure
for concrete
(page 132),
measure out the proportion
of sand and then mix the cement in
thoroughly.
AddcZearlwater
in the center of the pile and turn the
ingredients
over at least 3 times until
all streaks
disappear
and
the mixture
is even.
The mix should have the consistency
of
concrete:
wet, but not watery.
Moldina

Sand-Cement

Blocks

Sand-cement blocks may be molded by
hand or with a simple hand-press.
Blocks made by press are generally
stronger
and more durable.
But
blocks made by either
method are
acceptable.
Hand Molding.
If a commercially
made
mold 1s not available,
a mold? can be
made out of 2.5-5cm lumber in the
dimensions
desired.
Typically,
these
blocks are:
ACTUAL SIZE, cm

19.5 x 19.5
14.5 x 19.5
9.5 x 19.5

x 39.5
x 29.5
x 29.5

NObUNALSIZE, cm

20 x 20 x 40
15 x 20 x 30
10 x 20 x 30

Once the molds of the correct
size
have been built,
shovel the wet
mixture
into the mold and shake the
mold to settle
the contents.
Then re-fill
the
the top and pack
with a spade or
excess off after

mold slightly
over
the mixture
down
shovel.
Scrape any
packing thoroughly.

143
Next,

carry

the

full

mold to the curing

Turn it upside down gently,
from any previous
blocks.
Then,

lift

the mold off:

and place
first

area.
it

a few centimeters

away

the core;

then, the casing.
Repeat the process until
enough blocks have been
made. Using several molds simultaneously
will
greatly
speed the
process.

144

There
Molding With A Hand Press.
are several
types of has press
available
for making strong sandCinva-Ram and
cement blocks.
Tek-Block
presses are the most
press will
common, but any similar
work as well.
There are three basic steps in the
operation
of most hand presses:
0 loading

the mold box;

. compressing

ejecting

the mix;

the block.

With any hand press,
it is a good
idea to make a few test blocks
before starting
production
in
order to determine
the correct
amount of mix needed to make a
strong block.

i45

Curing
D

Sand-Cement

Blocks

with water after
they have
Sii. --cement blocks should be sprinkled
They should be dampened at least once a
set for about 12 hours.
They should not be laid up in a wall for at least
day for 5 days.
12 days after
being molded.

MAKING STABITIZED
Ingredients

EARTH BLOCKS

and Soil

Selection

The selection
of a suitable
soil
for mixture
with cement is crucial
in making strong stabilized
earth
blocks.
There

are,

roughly,

5 kinds

of soil:

- rock ranging
from 5mm
gravel
to 7.5cm;
- rock particles
5mm and
l
sand
smaller;
- very finely
ground rock,
l
silt
spongy when wet, but not sticky:
- very fine grained earth,
l
czQy
sticky
when wet, hard when dry;
- spongy, stringy
a orgcmic soils
appearance,
odor of decaying,
wet
wood.
.

The best natural
soil for stabilized
earth blocks is sandy clay.
As with
plain
concrete,
,the strongest
blocks
have a combination
of fine,
medium,
and coarse particles.
Earth that has
only one particle
size, or has mostly
organic
and/or coarse particles
is
unacceptable.

STABILIZED

EARTH B;OCK FORM

146
Testing

Soil

Acceptability

To determine
whether local soil can
used to make stabilized
earth
use the following
test,
blocks,
called
the "jar test":

Fill
a glass jar about l/3
full
of soil.
. Add water to the 2/3 mark.
Shake vigorously
for 11.minute.
: Let the jar set for an hour.
When the soil has settled
there should be 3-4 distinct
layers
in the jar.
If there
are not, reject
the soil.

Deciding

/VEGETABLE
HATTER
A VERY FINE
1 FINE
v COARSE

How Much Cement to Mix With

Once an acceptable
soil
much cement to mix with
This can be done easily

the

Soil

has been found, you need to determine
how
it to make strong stabilized
earth blocks.
with a "shrinkage
test":

Make a box 4cm deep, 4cm wide, and 6Ocm long.
Grease or oil the insides
thoroughly.
Fill
the box with damp, but not muddy, soil.
Pack the soil with a shovel. or spade, especially
at the corners.
Level the surface with a str,aight
edge or ruler.
Place the box in the sun for 3 days, or in the shade for 7 days,
and protect
it from rain,
The soil should shrink .and develop
3 or 4 cracks.
IT 6 o~more cracks
appear, or Zf the dried sdZ arches out of
the box, reject
the soil.
It will not make
good blocks.
As long as there are

less than 6 cracks and the soil lies
flat
in the box, measure the shrinkage .by tapping
the box and sliding
the soil to one .end:
If

the

shrinkage

lcm or less
lcm to 2cm
2cm to 4cm
4cm to 5cm
more than 5cm

is:

use a cement:
ratio
of:

soi 1
-

l-15
1-12
l-10
I- 9
reject
the soil, or
add sand and repeat
the test

147
Mixing

the

Ingredients

Once a sui table soil has been
it should be screened
selected,
through a wire mesh with holes no
larger
than 5mm.
After the soil has been screened,
measure out the proportions
of
earth,
cement, and any sand to be
added.
On a platform
or other flat
area,
mix the ingredients
thoroughly
as
for concrete.
Add water slowly with
can until
the mixture
not muddy.

To test
correct
handful

a watering
is moist but

whether you have added the
amount of water, squeeze a
of the wet mix into a ball:

If it can be broken in two
without
crumbling
and without
leaving
moisture
in the hand,
the amount of water is correct;
If the mixture
crumbles,
too dry.
Add more water
repeat the test.

it is
and

If the mixture
leaves moisture
in your hand, it is too wet.
Compress the mixture
and allow
the excess water to run off.
It is best to test the mixture
frequently
to avoid getting
it
too wet.

_-.

148
Curing

Stabilized

Earth

Blocks

The moisture
in stabilized
earth blocks should be eliminated
from sun and rain.
under cover, with the blocks protected
slowly,
For the first
3-4 days the blocks should be separated
in single
They should be sprinkled
rows, never stacked upon each other.
After
4
lightly
with water twice a day for this initial
period.
may
be
stacked
up
to
10
layers
high
in
a
pyramid
the
blocks
days r
On the 8th day,
fashion with a little
space between each brick.
bricks
may be laid
up in a wall where they will
continue
to cure
and gain full
strength
in about 30 days.

laying

Block

Foundations

When the footing
has been poured and
has cured for about a week, and the
blocks have been made, construction
of the foundation
wall can begin.
All block foundation
walls,
whether
or stabilized
sand-cement,
concrete,
are laid the same way.
earth,

SECOND COURSE

stack a number of blocks at
First,
line so
along each wall
intervals
that a szqply
is always
at hand.
FI RST COURSE

Next, lay out the planned number of
blocks for the first
row (course) on
or alongside
the footing
and check to
see'how well they fit the length of
Very small adjustments
in
the wall.
the length of a wall
(under 7.5cm
over the length of the whole wall)
may be made by increasing
the size
of mortar joints
between every 5th or
For example, if 8 joints
6th block.
are made lcm instead'of
&cm, the wall
length will
be increased
4cm without
cutting
any blocks.
To give the wall strength,
the courses
(rows of blocks) must be staggered
so
that the bond between any two blocks
rests over the middle of the block
beneath them.
To stagger the courses,
turn one
corner block on the first
course so
Then, on the
its "head" faces out.
turn the block at the
next course,
opposite
corner head out.
Continue alternating
between courses
in this way.

I
STAGGERED BOND

149
To ensure that the blocks are laid
in a straight
line,
run a string
from corner to corner along each
For outside
walls,
attach the
wall.
string
to the batter
boards;
for
attach it to a nail
inside walls,
hammered between two courses of
blocks.
[

If the string
sags, as it is likely
to do over a distance,
support it
with a piece of paper that is
weighted
with a small rock.
Use the string
as a guide, laying
each block up to but not touching thz
The string
can be moved up
line.
later
for each new course of blocks.
Once the string
is in place
first
course,
you are ready
prepare the mortar.

for
to

BATT,,,
BOARDSL

PAPER WEI GHTE0”;;

the

The recommended mix for mortar to
lay blccks
is 1:3, 1 part cement to
3 parts sand.
Mix these ingredients
with each other and with water as
concrete
is mixed (see page 132).
During the dry season, it helps to
sprinkle
the blocks with water
before they are laid in mortar.
This prevents
them from absorbing
too
much water from the mortar.
To lay the first
course of blocks,
use a trowel
to spread out a full
bed of mortar about 1.25cm thick on
the footing.
To prevent
the mortar
from drying
out before blocks are
laid in it,
spread only enough for
4 or 5 blocks at a time.
Using the batter
board lines as
guides,
position
the first
block the corner block - very carefuZZy: an
error here will
cause problems that
are hard to correct.
When the corner block is positioned.,
tap it down firmly
- do not pound until
it is solidly
bedded in the
mortar.

STRiNG
w-c..-.zj

-:-t
..
F

150

Butter
the ends of each new
block to bond the vertical
joints
Press each new
between blocks.
block against
the previous
one until
a solid mortar joint
about 15cm wide
is formed.
Keep trowelling
minimum: it will
the mortar mix,

of the bed to a
draw water out of
weakening the bonds.

Any excess mortar that squeezes out
between blocks should be scraped off.
It can be re-used if it has not dried
Once mortar dries out it must
out.
be discarded.

CHECKING LEVEL

After every 3 or 4 blocks are laid,
if
check the course with a level.
remove the blocks.
it is not level,
and lay them again.
add mortar,

Once the entire
first
course of
blocks is down, build up the corners
at least 4 or 5 courses up, or all
This will
give
the way to the top.
you something to attach the guide
string
to for the upper courses.

STORY POLE Bw

Use a story pole to check the height
and to check that
of each course,
all corners are going up evenly.

FIRST

152
FINISHING

THE MORTAR

After the mortar has set, but before
it has begun to harden, use a bent
round bar called
a "jointer'!
to
"tool " each joint:
run the bar along
each horizontal
joint,
pressing
against
the mortar firmly.
This
action will
seal the joints,
help
weatherproof
the mortar,
and improve
the appearance of the foundation
wall.
Cure the mortar by sprinkling
the
wall with water or brushing
water
on with a broom once a day for 2 or
3 days.

Rock

Foundation

Walls

Rock footings
and foundations
consist
of two parts:
a concrete
base 5-7.5cm thick,
and a rock-andmortar wall.
The procedure
for
laying both the base and the wall
is nearly the same as the procedure
for concrete
footings
and block
walls.
The bottom
7.5-10 centimeters
of the trench
will
serve as the formwork for the
concrete
base, so the sides and
bottom of the trench should be
clear and level.
As with any
concrete
footing,
care should be
taken not to disturb
the earth on
the bottom of the trench.
FIRST, dig the trenches.

SECOND, gather the rocks. This can be
done while the trenches
are being
dug.
The rocks should be 20-40cm
long on average.
Larger rocks tend
to be better
because they will
use
up less mortari
The rocks must be
clean,
so use water and/or a stiff
brush to remove all crusted
dirt
from their
surfaces.

152

Use the procedure
for pouring
concrete
footings
without
forms as a guide for this step (pages 127 and
mix of 1:2 3/4 :4.
Let the concrete
cure
1351. Use a concrete
for 2 to 3 days.

THIRD, pour the concrete.

Tie a string
to the
for laying
the rocks.
Use a mortar mix
parts sand.
Spread a mortar bed about
the concrete
base.
Bosition
the rocks
as if they were blocks.

FOURTH, Zuy the rocks.

Mortar all the joints
between the
rocks; the outside
surfaces
of the
walls don't have to be flush,
but
the joints
should be compact.
. Be certain
to lap all the joints
(that is, stagger the rocks) to
prevent
a straight-line
crack
from developing.
If possible,
alternate
the
direction
of the "corner"
rocks.
Finish
the exterior
mortar joints
in the wall with a jointer
to
strengthen
the joints
and help
waterproof
the mortar.
.

Keep the top surface
of the rock
foundation
wall as level as
possible.

batter
boards as a guide
of 1 part cement to 3
1.25-2.0cm
thick
on top of
and tap them into place

153

CONSTRiJCTION

OF FLOORS

After the foundation
walls are complete,
regular
walls,
a floor
should be started,
the foundation
walls.
Earth

but before starting
the
level with the top of

Floors

Earth floors
are easy to build.
For drainage,
simply place a
layer of dry fill
inside
the
area bounded by the foundation.
The fill
can be made of any
material
that will
not hold
water,
such as gravel,
rock,
broken brick,
or rubble.
The
top of the dry fill
layer
should be about 5cm below the
top of the foundation
walls.
The fill
will
be packed down
as people walk over it during
the rest of the construction
process.
When the walls are complete,
add a lo-15cm
deep layer of
hard earth and pack it down
either
with a shovel,
or by
walking
on it.
When the
hard earth is well-packed',
wet it down slightly,
and
sweep it out to complete the
floor.,

)HARD

PACKED EARTH

Foundation

Wall)

Concrete

Floors

FILL
concrete
floors
need a level of dry fill
Like earth floorsp
Dump the
underneath
for protection
against
ground moisture.
fill
inside
the foundation
walls so that it will
be packed
down by rain and people walking
over it during construction
The fill
should be composed of two layers:
of the walls.
broken brick,
or
rock, gravel,
a bottom layer of dry fill:
If dampness in the area
and a top layer of hard earth.
rubble;
is excessive,
a 5-7 cm. layer of sand with a sheet of plastic
(or other waterproof
material
on top) should be laid between
the dry fill
and hard earth.

a
CONCRETE
PACKED EARTH
f /

Ilf

The top of the hard earth
of the foundation
walls.

SAND (DPTHINAL)

should

be about

10 cm. below

the top

PREPARING TO POUR THE CONCRETE
Concrete floors
can be poured at two stages
process:
after
the foundation
wails are complete,
l
are put up;
after
the walls have been put up.
l

in the
but

construction

before

the walls

There is an advantage to the second alternative:
since the floor
and walls will
very likely
settle
at different
rates,
the floor
Another
may develop cracks if it is connected
to the walls.
advantage is that the walls and doors provide
easy protection
for
the floor
while it is curing.

if the fill
has been in place some
time, check that the hard ear,th is
at the correct
level--about
10 cm.
below the top of the foundation
walls.
If it has settled,
add
more hard earth and pack it down
hard.
Wet it and then pound it
with the end of a steel rod.
Use a straight
edge and a level. to
check that the surface
is
reasonably
level before the concrete
is poured.
Pound 6 or 8 wood stakes
(about
5 x 10 cm.) into the fill
so that
their
tops will
be even with the level
of the finished
floor
(the same
as the top of the foundation
walls).
These stakes will
guide
you during the pouring,
but they
must be removed before the concrete
settles.

POURING THE CONCRETE
The best concrete mixture
for floors
cement:24 parts sand:3 parts gravel).
described
on pages 132-135.

a 1:29:3 mixture
(1 part
Mix the cement as

frbm where you will
finish
Then, begin pouring in the corner farthest
and work back toward a door so you can get out without
walking
on the fresh concrete.
Pour the concrete
at the full
thickness-10 cm --don't
layer it.

156
As the area covered grows, begin
to level the concrete
off with a
a board about 5 x 10 cm
"screed"-and several
feet long that is
swept across the surface to keep
the mix even with the tops of the
guide-stakes.
Then, before

the concrete

1. remove the guide-stakes
fill
their
holes with

sets:
and
concrete,

2. tap any pieces of gravel
and rock that stick out
above the surface into the
concrete
and smooth the
surface over.
Using thin boards to kneel on or
walk across the surface without
..
marring the fresh concrete,
"finish"
the floor by sweeping a
trowel
or wooden "float"
across
A rectangular
the surface.
float
is best--approximately
.15 x -25 cm. The sweeping
action will
bring a smooth
cement-water
paste to the
surface of the floor.
Be
careful
not to bring up too much
if water collects
in small
water:
pools, the surface of the
concrete will
be too weak when
dry.
After the floor
has started
to
harden, but while it is still
sweep the surface with
workable,
This
will
give a rough
a broom.
texture
to the finished
floor
and
surface.
create a safe, non-slip,
When the floor
is finished
and is
left
to cure, close the, doors and
windows to keep children
and animals
from walking
on the surface.
The floor
should cure for at least
Keep the
4 days, and preferably
10.
surface moist by sprinkling
frequently.
Since so much area is exposed, the
concrete
can easily
dry out too
quickly.

157
CONSTRUCTION

M!!MDOWS-a.m., AND

OF WALLS,

DOORS

construction
of the walls,
Once the foundation
walls are complete,
This part of the manual covers
windows, and doors can begin.
two kinds of wall construction:
- Block or Brick Walls,
- Rammed Earth Walls.
BLOCK

AND

Making

the

BRICK
Blocks

and

WALLS
or Bricks

BLOCKS WITH CEMENT CONTENT
The procedure
for making concrete,
sand-cement,
and stabilized
earth blocks is discussed
earlier
on pages 140-148. For walls made
of these materials,
build
a mold for blocks
f the length of a
the f-length
bloc.ks will
make the framing
full-size
block:
of windows and doors considerably
easier
(see below).
ADOBE BRICKS
Adobe bricks
are made from clay and sand.
(very fine particle
material)
will
increase
sizes and strengthen
the mixture.
The proportions
a good mixture

Adding

straw

of these materials
can vary
to begin with would include:
0 6 parts sand,
0 24 parts clay,
13 parts silt.
l
or chopped

grass

will

always

Where available,
silt
the range of particle
considerably.

strengthen

But

the bricks.

Make some test bricks
and then adjust the proportions
as necessary.
Some things to keep in mind while experimenting
with different
proportions:
- silt
should never be more than 15% of the mixture;
- A healthy
amount of sand is necessary
to keep the clay
from shrinking.
On the other hand, too much sand makes
the mixture
watery and weakens the bricks
as they dry.

158

Mixing

Materials.

Use a mixing platform
as for mortar or concrete
(page 132).
Measure out and mix the proportions
and add water slowly:
if the
mud is too wet it will
slump gradually
while it dries outside
No large stones or lumps can be left
in the mixture,
the mold.
but stones up to 1.5 cm are all right.

Molds.
The most common adobe brick
it is made with a bottomless
9 x 14 x 29 cm.

has anom&zuZ size of 10 x 15 x 30 cm.
mold with amha2 inside dimensions of

Use hard wood for the mold.* It may be easier,
of sheet metal.
to line the mold with a strip
bricks
at a time are easy to make and increase
brick production.

Like blocks with cement
content,
adobe bricks
cannot
be broken neatly
into halves
or quarters.
So, for framing
windows and door jambs, it's
best to make a half-length
mold as well as several
regular
molds (see window framing below, page 162).

after
some experience,
-__
Molds
for several
the efficiency
of

390; Png Adobe Bricks.
Bricks can be made on flat,
often faster
and easier.
Place
table.
Fill
like

a clean
it with
mortar,

mold

level

(dipped

ground,
in water)

but

using

near

the

a table

edge of the

mlud, being sure to pack the corners.
should be workable but not sloppy.

The mud,

Clear any excess mud off the mold, but don't make the surface
too smooth-- the brick will
adhere to the mortar better
if it
has a rough contour,
Slide the mold briskly
off the edge of the table
it in a vertical
position
to the drying
site.

WATER BARREL
I
I

Gently place the mold on
close to the
JC?m$ ground,
last brick made. Let it sit
for a few moments, then lift
the mold up slowly.
Rinse the mold off thoroughly
(in a barrel
of water)
before making another brick
with it.

and carry

160
Curing
Bricks must be dry before they can be used; if they dry in the
wall they will
shrink and ruin the mortar bonds.
The bricks
should dry in the sun for about 30 days.
For the first
week or
should be protected
from rain.
Sheet metal
SOf the bricks
provides
a good protective
cover.
After
the first
week they
can be safely
exposed to light
rainfall.
Turn each brick

over every

5 or 6 days to assure

even drying.

A Note on Mortar
Adobe bricks
are generally
mix as the bricks.

Laying

Blocks

and

laid

with

mortar

made from

thesame

Bricks

The basic laying
procedure
for block and brick walls
is the same
for all types of block and brick and is identical
to the procedure
for .block foundation
walls
(see pages 148-151).
0

The top surface of the foundation,
or of the previous
course,
should be covered with a bed of mortar.
Apply the mortar only
on the edges of hollow bricks.
Cover the entire
surface of
solid blocks.

. Butter each new block or brick on its ends either
before or
after
it is placed.
Again, butter
only the edges of hollow
blocks;
butter
the entire
head of solid blocks.

‘ORE

161
. Use string
to guide the
placement
of each new block or L
brick
in a straight
line.
BUT NOT
Position
the blocks or bricks
TOUCHINup to but not touchhg

the string.

Press and tape each one firmly
into place so that the mortar
joint
is l-1.25cm
thick.
Do
not pound the block in place.

zz:z:?

@.&j
.pyf
:-'::;:.:,

..,

:::
After every 2-3 blocks or bricks
&~~
.a:::.+:..
check the course for level and
plumb.
Remove and re-mortar
any
blocks that are out of iine.

-.-.._....
.......&..~.~.-.L.:
.............>...'.....
:::z
..,.,..,
.......:,.
...:::.::,::..-.'...:..~..-..,..~~...

HOND ARRANGEMENTSFOR BLOCK AND BRICK WALLS
There are important
differences
between the bonds that
used with blocks and the bonds for adobe bricks.
Bonds for

BLOCKS With

should

Cement Content

The main bond for blocks with cement
arrangement
used in block foundation
easily
continued
through corners by
each corner block ( see page 148 for

When working with blocks,
intersection
of exterior
interior
walls
is treated
much like a corner.

the
and

content
is the staggered
walls.
This simple bond is
alternating
the direction
of
details).

I
i

162
When framing windows and doors, the
blocks next to the opening must be
half-size
in every other course:
hence the great advantage of using
a half-size
mold.

Bonds for

l3ricks

In any given course, adobe bricks
can be laid so that they are
stretchers
(that is, placed end-toor
headers
(placed side-toend),
side).
Thecomers of brick walls should be
built
up just as they are for block
walls,
using stretchers
and
alternating
the direction
of corner
bricks.
But after
different
length of
used most

the corners are built
up,
bonds may be used for the
the walls.
The bonds
frequently
-are:

. for bricks
with a cement
content,
headers for the first
course and then every 6th
course I with stretchers
in
between;

163
. for adobe bricks,
the first
course
4th course, with
between.

headers for
and then every
stretchers
in

Headers should never come closer than
60cm to corners.
Walls shorter
than
2 meters (for example porch walls
and half walls)
should not have
When beginning
a
headers at all.
course of headers,
start
with a &
brick:
otherwise
the bonds over the
rest of the wall will
not be properly
staggered.

Double

Brick

i$ BRICK TO ST/ fiT
8111LD UP CORNER FIRST
AS FOR BLOCKS

Walls

Bricks used in exterior
walls may have to be doubled to provide
adequate thickness.
Double brick walls are laid with alternate
courses of headers and stretchers,
beginning
with stretchers.
The illustrations
below show how to handle (a) the length of the
(b) corners,
and (c) the intersection
of exterior
and
walls,
interior
walls.
(a)
STRETCHERS PAI RED

EXTERIOR WALL

164

Framing

Windows

and

Boors

Windows and doors in block and brick walls must be planned so
their heights
are coordinated
with the size of the block or brick
used (see pages 95-96).
All windows and doors consist
of 3 basic parts:
the head, the
and the jamb. In addition,
there must be a lintel
above the
sill,
opening to support the blocks or bricks
over the open space.

FRAMING WINDOWSAND DOORS IN BLOCK WALLS
In
of
be
the

block walls,
the lintels
should be made
There sh,-Td
----a- also
reinforced
concrete..
a concrete
sill
about 7cm thick
under
wood s.ill of the frame.

Frames (heads, jambs, and sills)
should be
wood, usually
2.5cm x 15cm hardwood lumber
in block walls.
To build the
a block wall,

space for a window or door
follow
these steps:

JAM6

WOOI
...
e?
I.
9:

Lintel
1. Make a mold for the reinforced
The mold should
concrete
lintel.
be as wide as the wall,
as deep as
the height
of 1 block,
and 13 times
as long as the window or door is
wide.
2. Fix 2 reinforcement
rods in
the mold and pour a 1:2:4 concrete
Remove the mold and cure
mixture.
the lintel
as you would a concrete
footing
(see page 136).

FRAME FOR LINTEL

CONCRETE
SILL

165

The Sill
3. Make a mold for the concrete
sill.
The mold should be as wide as the wall,
about 7cm deep, and as long as the window
Then, pour a 1:2:4
or door is wide.
concrete
mixture
and cure it just as the
lintel
was cured.
4. Prepare the surface
of the wall
the sill
will
be placed by spreading
of mortar on the blocks.

where
a bed

5. Put the sill
in place and press it
down firmly
until
the mortar joint
is the
same thickness
as the joints
between
courses.
6. Immediately
check for level and adjust,
by forcing
one end down.
If
if necessary,
the sill
is not level after
this,
take it
add mortar,
and repeat.
off,
TEMPORARY
BRACE 1

The Frame

(2.5cm x

15cm

hardwood)

7. Place the wooden frame
sill
and hold it in position
temporary
braces.

on the
with

concrete

8. Continue
laying blocks on either
side
of the window: the wall must go up evenly
on both sides or it will
qo out
of plumb.
9. Attach the frame
mortar and with nails
masonry.

to the wall with
hammered into the

10. At the top of the opening,
pre-cast
lintel
like a block:
l

lay

the

if the walls are more than 75cm
thick,
allow a few hours for the
courses below
to harden before
placing
the lintel:
apply mortar to the blocks or
bricks
at both ends of the lintel
and adjust
for the same joint
thickness;

. check

for

level

and adjust.

FRAMING WINDOWSAND DOORS IN ADOBE BRICK WALLS
Adobe brick walls require
wood
lintels
and sills
that serve as the
head and base of the frame.
The easiest
method is to make the
lintel
and sill
equal to the height
of the brick used (usually
10cm)
so
you do not have to cut or make bricks
in half-heights.
When the wall reaches
or at floor
level
for
the frame in position
mortar and support it
The jambs of the frame
thick..
Check for

-T-

MULL I ON >

window height a door - place
on a bed of
with braces.
should be 5cm

level.

Lay the next course or two of bricks
At this point,
the wall
and check again for level and plumb.
_ . on
each side of the frame will
exert enough pressure
to keep it in
position.
support the lintel
with a
Before laying
bricks
over the lintel,
The
temporary
5cm x 1Ocm or 1Ocm x 1Ocm post, called
a mullion.
mulIion
should remain in place until
construction
of the wall is
complete,

Roof

Preparation

Near the top of the wall,
attaching,
and providing

preparations
support for,

must be made for
the roof.

There are two basic kinds of preparation:
wall plates
and ring
beams.
They are built
and used in the same way on all block
and brick walls.

167
WALL PLATES
Wall plates
are solid,
continuous
wood beams (usually
5cm x 15cmj that connect the
exterior
walls
of a building
along their
tops and anchor
the roof to the walls.
They
are essential
in all buildings
except bamboo structures.
The wall plate can be held
place with 3 devices:

a a good mortar bed; as thick
as the horizontal
joints
in
the rest of the structure:
. steel straps
(bale iron wire)
anchored l-3 courses below
the top of the wall
(at
least 20cm); place the
straps in the appropriate
mortar joint
every 3-l meter;

BALE IRON

. bolts anchored l-2 blocks or
bricks
below the top of the
wall every 2 meters:
-with small bricks,
the
bolts can be anchored with
a thin metal plate
(called
a
retainer
plate)
between mortar
joints;
the bolts
can be placed
-with hollow blocks of whatever size,
in a core and the core filled
with concrete
(1:2:4 mix).

Corner
joints

joints
of the wall
or batten joints.

plate may be fastened
Battens are slightly

BATTEN JOINT
WITH BALE IRON STRAPS

either
with
stronger.

lap

LAP JOINT
WITH BOLTS

RING BEAMS (ALSO CALLED THE BEAMS)
A ring beam is a continuous
reinforced
concrete beam poured in
place at the top of concrate block
l&.ztts only.

Ring beams help the walls resist
the outward-spreading
pressure
from
the roof, provide
extra
reinforcement
in earthquake
areas,
and provide
a solid base on which
to attach the wall plate.

RCEMENT RODS
ST COURSE OF %L.OCK

REINFORCEMENT BARS

169

Ring beams are poured in place,
so
formwork must be attached
to the
sides of the walls already
up.
The beam should be about 15cm deep
and exactly
as wide as the wall.
It should also be reinforced
with
2 steel rods l-l&cm in diameter.
Follow the guidelines
formwork on page.129
1:2:4 mixture.
To avoid

for concrete
and use a

any seams, ring beams must
one continuous
operation.

be poured in

RAMMED

EARTH

WALLS

Rammed earth walls are built
in layers by packing a damp earth
mixture
into temporary
forms, allowing
each layer to dry slightly,
and then moving the forms to repeat the process until
the walls
are as lligh as planned-..
Earth

Mix-ture

The earth used should be basically
the same mixture
used for adobe
However, the proportions
bricks
(page 157).
of ingredients
are not
critical.
Large amounts of straw added to the mixture
will
increase
the strength
of rammed earth walls significantly.
Only a little
and damp (not
If

water should
muddy).

be added to theearth

until

is firm

a suitable
grade of earth can be found, properly
damp (after
season),
it can be brought directly
to the building
site
used as-is,
or with straw added.
rainy

the
and

Forms
. I RON STRAP

The most manageable size for the
forms is 45cm deep by 2 meters
long and 37~.5-45cm wide,
depending on the wall thickness
planned.

III

FLAT I RON BAR
(TO StjPPORT MOLD)

The forms should be closed on 3
sides:
the open side is placed
against
the previous
section
of
wall.
There can't be any
inside
the
spreaders
or supports
comes
form, so the form's strength
from battens
on the outside
held in
place with iron straps at the top
and flat
iron bars at the bottom.
Two special
forms should be built
for corner sections
with alternate
long and short sides.
The se
"corner"
forms are held together
with interlocking
iron pins in
addition
to the strapped battens.

LONG SIDE

25ciii

: RDN P-ii

Rammed earth is not very easy to
mold or shape once in place,
so
planning
beforehand
is essential.
First,
mount the forwork
on the
foundation
wall,
using-iron
straps
or wire around the battens.
Check
the form for level and plumb.

CORNER FORi4 DETAIL

Place 1Ocm of earth in the form
and pack it down solidly
with a
small rod about 4cm in diameter.
Use quick,
short strokes.
The
corners must be especially
wellpacked.
As much as possible,
avoid shaking
or vibrating
the wall since this
tends to loosen the earth.
Add more earth and ram it down until
there is a firmly
packed layer 30cm
deep.
Scrape lines about $cm deep
in the top suzfacs to give the
section
some additional
"grip".

171
REVERSE MOLD FOR EACH COURSE

Wait at least an hour before
removing the form and starting
new section
above the first.

If the earth on top of an old layer
it lightly
has become dry, sprinkle
to dampen it before putting
new
earth on top of it.
Overlap the corners by alternating
This will
short and long legs.
greatly
increase
the strength
of
the walls.
Rammed earth walls can be
Run a steel band
reinforced.
around the entire
building
just
Rbove the door and window level.
A
second band can be run just below
the roof if desired.
CE

To guide the steel band around
drive pegs about 20cm
corners,
long into the rammed earth before
removing the form.

Framing

Windows

and

IN FORCEMENT

Doors

Windows and doors are framed
according
to the same basic
procedure
followed
with adobe brick
Use
walls
(see pages 164-165).
wooden sills
and lintels
about 5cm
thick.
place the sill
r'irst,
top of the damp earth.

in the proper place
Check for level.

Wext, place the frame, including
the sill,
and brace it.
Then place
up on both

forms on either
checking
sides,

Finally,
before building
temporary
brace.

and press

the combination

into

the

head-lintel

side of the frame and build
the walls
the frame frequently
for plumb.
above the

lintel,

support

iz. with

172
Roof

Preparation

To mount a wood wall plate on the
top of a rammed earth wall, place
steel rods in the wall about
3-l meter below the top of the
Then wrap iron straps
wall.
around the wall plate and
fasten both ends of each strap
to the steel rods.

CONSTRUCTION

OF ROOFS

It is a good idea to coat all
an anti-termite
solution-such
In areas with very
have an experienced

Flat

strong
local

wood and bamboo roof materials
with
as carbonyl, .. Xylophene,
or Creosote.

winds or storms,
it may be advisable
contractor
check the roof plan.

Roofs

To build
a flat
roof,
the steps below:
l

WA1

simply

Place the beams across the top
of the walls every f-l meter and
lash them securely
to the wallplate with iron straps or
staples.
Avoid nails
through
the beams since they may split
the wood.

. on the

ground, construct
the purlins
out of
sections
of 5cm x 1Ocm
Purlin
sections
wood.
should be spliced
as shown, wtth
together,
the Zonger piece over the
shorter piece. Take care

CORRECT: Long piece
piece

suppvrted

by the

short

that splices
will
not
be directly
over a beam
once the purlin
is in
Each completed
place.
purlin
should be lifted
into place and lashed
witn iron straps to each
beam.
0

Shed

the roof
Finally,
covering
should be
attached
to the purlins.
Follow local custom when
using materials
such as
thatch,
mud, or tile.
Avoid corrugated
metal
for flat
roofs:
the
metal sheets make
buildings
very
uncomfortable
in hot
climates
and tend to
rip off easily
in wind.

INCORRECT:

Nails
are not strong
enough
support
the long piece

Roofs

Simple, beam-supported
shed roofs
for buildings
where one wall is
built
higher
than the other-are
constructed
according
to the same
procedure
for flat roofs.
One Wall

Higher

174
For truss-supported
follow
these steps:

shed roofs,

STEP 1. Place beams across the
top of the walls as for flat
roofs.
However, these beams may
be further
apart,
up to 1.3-i.4
depending on the roof
meters,
covering
to be used (closer
for
heavier
materials,
further
for
The beams
lighter
materials).
must be as long as the distance
between the two walls they will
rest on + the overhang planned
on each side.

STEP 2. On the ground,
and -mark off the outline
truss.

measure
of the
P

m---i
-=- ---0
------r,--

---l4

-;I-0
------I

fiil
1
I

STEP 4. Fasten the pieces
the truss together,
either
bolting
or nailing
them.

of
by

Whether bolts or nails are used
the -joints may be
as fasteners,
made either
by overlapping
pieces;
or,

by using single
or double plates
(separate
pieces of wood) to
hold the truss members together;
err

When splicing,
use
by splicing.
iron straps to reinforce
the
joint
fur-ther.

176
STEP 5. Repeat steps
beam in the roof.

3 and 4 until

the trusses
STEP 6. To position
follow
the instructions
material,
Gable

a truss

has been built

and attach purlins
for gable roofs

for

each

and roof
below.

Roofs

To construct
a gable roof,
follow
the steps below:
STEP 1. With a tape measure,
mark off the outline
of the truss
-- the di-stance from the rafters
to the tie beam, from the struts
to the tie beam, and so on -- on
Loosely organize
the
the ground.
pieces for the first
.truss along
the lines marked and hammer
stakes in the ground to hold each
member in place.
STEP 2. Check the measurements
of the pieces on the ground
'against the plans and make any
needed adjustments;
then make
sure the stakes are firmly
in the
ground and won't move.

STEP 3. Assemble the truss with
permanent connections
as for shed
roof trusses
using theconnections
indicated
on page 175.
STEP 4. As each truss is
assembled,
put it up by pushing
over the wallmt,
and then
raising
the point of the truss
with a long pole.

it
TEMPORARY PURLINS

first,
STEP 5. Put the end trusses
Then
bracing them from the ground.
run a string
from apex to apex and
align the other trusses with the
string.

TRUSS /i.

J/N

,LS AS TRUSS SUPPORTS

in place
STEP 6. Hold the trusses
with temporary
purlins
nailed
to
down
each one'. Then tie the rafters
to the wall plate with bolts or
iron straps.

I RON

the
STEP 7. Next, construct
purlins
on the ground, rather
Stagger the
than on the roof.
joints
in the purlins
to avoid
sagging in one section
of the
roof.
Be sure that no joints
are placed directly
over a
truss beam: too many nails will
split
the l-umber of the truss.
STEP 8. Attach the purlins
to the trusses,
starting
20cm from
the top of each one.
The position
of each purlin
should be
marked in advance by running
a string
from end-truss
to end-truss
and placing
a nail at the purlin-point
on each truss
(the nail
will
keep the purlins
-from sliding
until
they have been attached
by bolts or iron straps).
For local roof-covering
materials
such
as tile,
mud, or thatch,
space the
purlins
according
to local
practice.
For sheet metal,
use
the following
formula:

178
Where

x = Space between
purlins,
=
Length
of
metal
sheets,
and
Y
each sheet will
overlap
1Ocm = the length

STEP 9.
material.
practice

200~71 sheeting

one

beneath

Y - 1Ocm

X =

%AMPLE:

the

will

be used, the fomlu

2oocm - 1ocm c 2 = 19ocm + 2 =

would then yield:
each purlin.

95cm betieen

Attach the roof-covering
Again, follow
local
for local materials.

Corrugated
sheets should be
attached
with specially
galvanized
large-headed
nails through the tops
wt in the valleys,
of
of the curves,
each sheet.
Nail the sheets through
attemate
rises wherever the sheets overlap.
third
Nail them every
middle of the sheets.

rise

y
Piq
+,~..,.
L

- 1
nTTAPU;\reav

in the

The nailing
should begin at the
bottom of the end of the roof
farthest
from the prevailing
wind
to minimize
wind and rain that
will
blow between the sheets.
For example, if the winds come
mostly
from the east, begin at the
lowest part of the western end of
the building.

‘(

Stagger corrugated
metal covering
so that each row of sheets covers
the joints
of the row beneath.
Take care also to stagger the nails
line
so they do not form a straight
Such a straight
along any purlin.
line might split
the purlin
underneath.
Patch
metal
metal

any small holes in the
with "Masticon"
or a gummed
tape called
"Flashband".
NOTE: Metal

Sheet

Should

be Staggered

179

STEP 10. Build a crown to cover
the top of the roof by cutting
metal sheets lengthwise
into
3 parts,
pounding each part flat,
bending it over the ridge of
and nailing
it to the
the roof,
metal sheets and purlins.

24?.801

0 - 77 - I4

Bamboo is an excellent

building

material

for

several

ratio
it has a very high strength-to-weight
sturdy for such a light-weight
material;

it is easily
to remove;

handled,

with

little

waste

reasons:
--

very

and no bark

it adapts to a variety
of uses; a few bamboo plants
in the backyard will
provide
enough bamboo for a
extra rooms, or a house;
fence, a pigpen,

after
construction,
income-generating
so on.

bamboo can be used for other
crafts
such as baskets,
mats, and

About the onlypartsof
a building
that cannot be made rrom bamboo
However, bamboo is rarely
used as
are fireplaces
and chimneys.
Usually
it
the only construction
material
for a whole building.
is combined with other materials:
wood, clay,
lime, cement, iron,
thatch,
and so on.
palm leaves,
They differ
in thitKness,
strength,
There are many bamboo species.
Each
is
useful
and resistance
to insects
and decay.
flexibility,
a
species
that
For
example,
in only a few parts of a building.
makes good supporting
columns cannot be used to make screen matting
The general characteristics
of different
species are
for a window.
But when in doubt about a specific
bamboo supply,
discussed
below.
the best thing to do is check local practice
and/or seek advice
from a local contractor.
To balance
construction
l

its

advantages,
material:

bamboo has many drawbacks

It is usually
Uneven Dimensions.
necessary to ha-ve a large
supply in order to weed
out pieces that are too
thin,
too crooked,
broken, or otherwise
useless.
Uneven surfaces.
Variations
in the
diameter
of the shaft
(called
a culm),
in the
prominence of the nodes,
and in the rate of
tapering
at the end of
the culm all make
certain
applications
On the
difficult.

FQI

as a

183
other hand, long culms can
often be cut up and the tips
used for one purpose while
the shafts
are used for
another.
l

Bamboo

Brittleness.
In almost all
cases bamboo cannot be
nailed.
Most bonds are made
with wire or hemp lashings.
A few thick-walled
species
can be bored to insert
pegs.
Low durability.
Bamboo is
susceptible
to insects
(especially
beetles
and
termites)
and to rot.
Both
insect
decay and rot can be
chemically
retarded,
and
some species are more
resistant
than others.
But
even in the best cases, bamboo cannot last much more than
5 years
in weight-bearing
parts of a building.

for

Foundations

Bamboo is basically
with a preservative,

an above-ground
material.
Unless it is treated
it will
last only 2-3 years underground.

However, bamboo will
serve as a supporting
post: for a house on
stilts,
for example.
Use the largest
diameter
culms (at least
12-20cm) with closely
spaced nodes for stiffness.
If only
'smaller
shafts
are available,
they
can be bound into columns.
Bamboo

for

Frames

In earthquake
areas, bamboo's
flexibility
makes it a good choice
for construction
of a frame for
floors,
walls,
and roofs;
Such a
frame may then be finished
by
weaving bamboo to form the solid
parts of the building,
or by using
other materials
such as clay, mud,
or thatch.
Use only whole culms.
Cut off and
discard
the upper, tapered ends of
each culm so that all shafts
used
will
have uniform
thickness
and
strength.
247-80,

0 - 77 - 13

184
The design

of a bamboo frame

is simple:

in the corners
set out at
Begin with corner posts firmly
planted
Next, attach joists
(horizontal
cuPms that will
support
the site.
Then attach studs (vertical
culms that will
the floor
and roof).
form the wall frame).

(STUD

Since
shafts
cun be
upper

bamboo cannot be cut to make perfectly
measured joints,
the
The only cut that
must be lashed with vinesp bark, or wire.
made is a notch or cradle-like
cut that can be used at the
end of posts to support a horizontal
piece.

185

Bamboo

for

Floors

The culm of certain
species can be split
open and flattened
out,
making a "board".
Among other uses, these boards can be laid
directly
on a hard earth surface
to make a floor.
Clay is the
best soil for this purpose.
It
should be evenly graded (for
proper drainage)
before the boards are pounded into place.

BAMBOO BOARDS MADE BY SPLITTING
LARGE CULM AS SHOWN

Another type of bamboo floor
is raised 1.5-2
meters so that the
space underneath
may be used for storage of equipment or anj .mals.
Thick culms are used as column supports*
thinner
culms are
flattened
for the floor;
and woven mats'are
used as floor
covering,
I
I

Bamboo

for

Walls

Here are two common ways to use bamboo
for walls:
. Wide bamboo shafts are lashed
horizontally
to both sides of
vertical
hardwood posts.
Occasionally
thick bamboo posts are
The
used instead of hardwood posts.
the
bamboo
shafts
may
spaces between
be filled
with mud, mud and stones,
or more bamboo.
thatoh,

Sprung
around
plaster

bamboo shazts are woven* _.
Vertical
Strip Construction.
The
frame
is then covered wltn
three horizontal
poles.
on one or both sides.

OF PLASTER

DL ,AYER OF PLASTER

Partitions
may be made exactly
as walls are but with .lizE;a;,and
Use the lightest
species available.
portable
frames.
then
weave
them
into mats that can be suspended.
flatten
the shafts;

Bamboo

for

Doors

and

Windows

For practical
reasons,
doors
and windows are kept to a
minimum in bamboo housing.
Doors tend to be made of:
e wood: or,
. bamboo matting
woven on
a bamboo frame: or,
. bamboo "bars" put up in a
gate-like
fashion.

Windows are usually
unscreened and
covered with bamboo matting
or a
palm leaf.
They can also be made
out of a row of shafts tightly
pressed and bound together
by pieces
of wood: this kind of window, when
acts as a shade'.
raised,

Bamboo

for

Roofs

Bamboo is used for the frame
be of several materials:
. grass

of the roof.

thatch;

e corrugated

metal

or asbestos:

. tile;
b bamboo tiles

made from.halved

culms.

The roof

covering

can

188
Bamboo

Weimforcern~t

of Concrete

Bamboo can'be used to increase
the strength
of concrete
by 2 to 3
- dried
the shafts must be "seasoned"
To be effective,
times.
out and shrunk for a month or more and then split
in half.
The placement
reinforcement
page 137).

Preservation

The following
bamboo:

of the shafts
is the same as the placement
of iron
rods (see the section
on reinforcing
concrete,

of Bamboo

simple

steps

will

lengthen

the useful

life

. Cut the shafts at the base and store them upright
in
clumps in a dry, sheltered
place.
Never store bamboo
out in the open or expose it to rain or dampness: It
may rot or be eaten by insects.
. Dust the ends of each shaft with
safer insecticides
talc
(or other,
effective).
. Use pegs to keep the ends off

the

a mixture
of 1:20
where available

DDT to
and

ground.

trim all twigs and leaves
. After 4-8 weeks of-drying,
the shafts
and dust the newly cut surfaces.

off

LATRCNES

190
LATRINES

Latrines
are vital
for community
They keep local watar used
health.
for drinking
or growing crops free
from diseases
spread through
and they discourage
human feces;
transmission
of diseases by flies
that breed in excrement.
In many areas,
community
acceptance
of latrines
as an
integral
part of any home,
or clinic
project
may be
school,
more important
than any other
construction
ideas in this
manual.

a latrine
consists
Basically,
of: a p&t dug in the ground for
the storage of excrement;
a base
built
over the pit with a small
hole in it so that a person can stand over the pit;
and a shetter to
provide privacy,
protect
against weather,
and to keep flies
from
breeding
in the pit.

Two principal
requirements
should govern the choice of a latrine's
location:
* It should be close enough to the school,
clinic,
or home to
but far enough away to keep the main
be reached easily;
30 meters
building
free of odors and potential
contamination.
is the distance
recommended by many experts.
* It should be situated
so
that it will
not contaminate ground or surface
water that may enter
springs,
wellsip or
Satisfying
fields.
this requirement
can
sometimes be complex.
The most important
considerations to keep in mind are:
l

the latrine
should be high
enough so it will
not be
flooded
during the rainy
season;

191
. the latrine
should be &x.m~iZLfrom any nearby wells
if this is impossible
- of if the land is flat
latrine
must be at least 15 meters away from wells
(?.5 meters in sandy soil);
l

in regions with fissured
(which can carry pollution

rocks or limestone
great distances),

or springs;
the
or springs

foundations
get expert

advice!

At the chosen location,
begin by digging
a pit,
either
ro;;:
or
and from l-3 meters deep.
square, about 1 meter across,
table below shows recommended depths for a latrine
for a family
in public
of 5. The same depths may be used for latrines
be 1
provided
there will
buiidings
such as schools or clinics
latrine
for every 15 people who use the building
regularly.

RECOMMENDED DEPTHS FOR HOLES WITH 1 SQUARE METER AREA

PERSONAL CLEANSING MATERIAL

w-s-

to pits which penetrate
Wwet pit type" refers
On the table,
"Dry pit
warer table in the ground and are constantly
wet.
refers
to pits that are 3 meters or more above the highest
underground
water level.

the
type"

If the soil is soft and tends to cave in during
the digging,
line
the pit with stone, brick,
wood, or bamboo to keep the sides of
Even when the soil
is firm,
it's
a good idea to
the pit strong.
line the upper few feet.

The base is essentially
a foundation
for
to prevent hookworm larvae and burrowing
pit.

It also helps
the floor.
rodents from entering
the

The best materials
for the base are concrete
from a 1:2 :3 mixture,
Heavy hewn logs
or stabilized
earth with S-6% cement content.
treated
for insect
resistance
ray also be used as shown.

Following
construction
of the base,
a mound of Shard-packed
earth or dry
fill
should be built
up until
it is
level with the top of the base (at
least 15cm above ground level),
and
it covers the floor area planned
for the shelter.

l&m

-I

Above this mound must be placed a
floor with a built-in
hole about
Do not
40cm long and 12-18~~1 wide.
make the IioZe tier
than 18em or children
through it!

may fall

The shape of the hole can vary
according
to local preference.
common shapes are shown.

Two
12cm

193
The floor may be built
of several
materials.
Reinforced
concrete
Build a form about 1OOcm x 1OOcm and 6cm deep.
is best.
Then
cut a piece of wood 6cm high and the size and shape of the hole
This piece will
act as the mold for the hole in the
desired.
If you slope its sides slightly
instead
of making
concrete
slab.
them straight
up and down, it will
be easier
to remove from the
concrete
after
the concrete
has set.
Place the wood piece inside
the 1OOcm x 1OOcm form where you
want the hole to be.
Then place reinforcement
rods (bamboo or
iron)
in a grid across the formwork.
Mix, pour and cure the-concrete
as you would for any concrete
floor
(see pages 154-156).
After curing,place
the concrete
slab
over the mound and base so that the hole is centered
over the
pit opening.

Other materials
appropriate
for
building
latrine
floors
include
reinforced
brick mortar,
wood,
and logs with earth.
It may be desirable
to add raised
foot rests,
approximately
30cm
long and 1Ocm wide as shown.
In addition,
a simple wood cover
can greatly
reduce odors and keep
flies
away from the pit.

Shelter

The latrine
. protection .

shelter

serves

from wind

several

purposes:

and rain;

. privacy;
. protection
of the pit from direct
and other disease-carryivg
insects
in the pit).
In general,
the shelter
should
long, and 1.5 meters high.

be about

light
(darkness keeps flies
and rodents
from breeding
1 meter

wide,

It should have a shed roof with a large overhang (about
The roof should be lo-15cm above the walls for ventilation
diffuse
any odors which might build
up.

1.5 meters
GO-100cm).
to

If acceptable
socially,
it is best to cut all vegetation
within
2 meters of the shelter,
especially
if food is grown nearby.
This will
prevent contamination
of the ground surface
resulting
from any possible
misuse of the latrine.
The illustrations
above show two types
actual construction
of latrine
shelters
procedures
for any building.

of latrine
shelter.
follows
the normal

The

One final
note: The latrine
design described
in this manual is
only one of the many possible
designs.
See the sources listed
in the bibliography
(page 227) for information
on other designs.

STRUCTION

EARTHQUAKE

AREAS

196
CONSTRUCTiON

IN EARTHQUAKE

AREAS

In areas where earthquakes
or tremors are likely,
number of ways to reduce the danger of structural
increase
the safety of those who use a building.
should be taken in:
. the selection
and preparation
building
position;
a

the

selection

of building

of the site

there are a
damage and to
Special
care
and the

materials;

. the use of special
techniques
for reinforcing
foundations,
floors,
walls,
and roofs.

Sdectiore

and

Preparation

of the

Siie

One of the simplest
precautions
against
earthquake
destruction
is
The
to choose a site as far as possible
from the fault
line.
fault
line is the line along which two blocks of earth meet and
slide against
each other.
Earthquakes
occur when two such blocks
of earth move suddenly.
In areas where a serious
ez r+hu-ke
has occumed recently,
people near the fault
line will
know where it is.
Fault lines
may also be found by looking
for places where geological
formations
such as dry river beds or veins of rock appear to
have suddenly split
and shifted.
The location
of such shifts
will
be on the fault
line.

197

Other suggestions
for the
selection
of a site in
earthquake
areas include
the
following:
- Flat terrain
is best;
avoid: sharply
sloping
ground if possible;
ground
slippage
occurs most often
on hills.
- If the land has some slope
to it,
level the entire
site around the building
so that the foundation
and
walls are the same height
throughout.
Stepped
foundations
and walls of
un-equal
height are less
stable.

STEPPED FOUNDATION IS INCORRECT
(Wall
Height
Unequa 1)

LEVEL FOUNDATION IS CORRECT
(Wall
Height
Equal)

- Do not build on "filled-in"
earth:
it can't be as stable
as ground that has settled
naturally
over time.

- Align the building
so that
its length
is parallel
to the
nearest
fault
line.
This
will
help the structure
go
"with"
and not "against"
a
tremor.

with

-. Choose a site as far from
other buildings
as possible.
The minimum distance
between
l-story
structures
should be
equal to their
height.

fault

line.

198
- If a new building
must be
tdilt
less than the minimum
distance
.from another
any separation
is
building,
better
interconnect
buildings.
than

rwne.

Never

of two

the walls

INCORRECT: Walls

Connected

- Use rectangular
or circular
shapes for buildings
in
Avoid
earthquake
areas.
"L-shaped"
buildings.
CORRECT: Bui 1 dings

Selection

eb Building

Separate

Materials

the safest materials
Generally,
lightest
and most flexible.
concrete
In foundat&ms,
.bamboo,and concrete
or
rock foundation
walls
to bind the rocks are

in earthquake

areas

are the

footings
reinforced
with iron or
Avoid
block foundation
walls are good.
because the large amounts of mortar used
easily
weakened in earthquakes.

For waZZs, where

climate
permits,
bamboo and wood are the best
because their
flexibility
keeps them from cracking
or collapsing,
Walls made
and because they are less dangerous if they do fall.
from bricks or blocks of any material
are fine but should be made
F&mmed earth walls and rock
as light
and as thin as ossible.
walls are unstable
and %angerous in earthquakes:
they should be
avoided.
Roofs are

safest when made of bamboos and grasses
(thatch).
Wood-beam supported
roofs are also fine,
provided
the material
such as shingles
or corrugated
metal.
they support
is light,
Adobe and tile
roofs should be avoided.

Reinforcemeht

of Buildings

There are many ways ofreinforcing
buildings
to resist
earthquakes.
The most important
and least expe;?sive techniques
are listed
But if earthquakes.are
a major problem in the local area,
here.
the field
worker or community should consult
experienced
local
contractors
for advice.

199
All of the techniques
listed
here can help save a building
in an
whether they are used alone or in any combination.
earthquake,
They cannot guarantee
that a building
will
survive
a severe
earthquake
intact.
But even in the worst case, they will
give
people more time to get outside
safely,
before the building
collapses.
To strengthen
or iron rods.

foundations

To strengthen

walls:

. place

windows

. place .Inside
as pass-%le;

and floors,

and doors
doors

on opposite

as close

reinforce

them with

bamboo

walls:

to the middle

of interior

walls

. place timbt:
posts at the ends of interior
walls
(see the
section
on window and door frames, page 96, for details
of
construction);

mount exterior
doors so they
open to the outside
(this
permits
faster
escape during
a quake);

. allow at least 1 meter of
wall space between openings
and corners;

. connect all walls with
interlocking
wooden beame
at the tops of the walls,
and preferably
at the
floor
and lintel
levels
too;

reinforce
wooden frame
walls with cross- supports:

. use a "tight"
bond between
brick or block courses;
too
much mortar will
weaken the
wall.

APPENQICES

-e

202
1. CALCULATIONS
TO CHECK
SUPPORT
A IBUILDING

WHETHER

A PROPOSED

SITE

WILL

If there is doubt whether the soil at a proposed site will
it may be necessary
to estimate
support a building
(see page181
both the we{ght of the planned building
and the weight-bearCng capacity of
This section
contains
step-by-step
directions
and tables
the soil.
for both these estimates.
IMPORTANT NOTE: The weight

estimated
a
l

its

until
size

the builders
and shape

of roof

be made of and how thick
it

will

CALCULATING A BUILDING'S
Several calculations
per square meter.
Equuttin

have

they

will

(page 101-114).

must be made to estimate
a building's
For the purposes of estimation,
figure

weight
that:

Weeht per
square meter

mzt

of longest
(kg)

To find the weight per square meter,
needs to determine
each of the three
Equath
2. Follow these steps:
Enter
1:

the planned

length

Weight per
squure meter

wall

(ml

therefore,
the planner
first
items on the right
side of

of the

of longest
wall (kg)

weight

+ weight of roof
supported by
longest 7xrlZ (kg)

of longest

length

Equation

WEIGHT PER SQUARE METER

weight

STEP 1.
Equation

cannot

(page 22-43);

what'its
walls will
be (page 92-951;

. what kind

of a planned building
have decided:

longest

+ weight

wall

of roof

supported by
longest w&i?1 (kg)

203

STEP 2.

Calculate

Equation

the weight

of the

longest

wall.

Weight per
squaxe meter
length
(a)

Use the following
equation
weight
of the longest’wall

Equation

Use Table
thickness

determine

waZ1 Cm)

the

Weight of
longest wall

(b)

of longest

weight
=

A to find
the
of the material

weight
with

pf 1 sq. meter
wall

per sq. meter for
which the building’s

number of sq. meters
in longest wall

every centimeter
of wall
walls
will
be built.

Table A
wall
(c)

Multiply
the number you find
in
Table A by the thickness
of the
building’s
walls.
The result
will
be the weight
of 1 sq. meter of
wall ; enter
it in the correct
place
in Equation
2:

Equation

concrete block
stabilized
earth
sand-cement block
adobe
stone/rock

125

75
125

150

WeCght ,of
longest ml1
(d)

kg/sq. meter
per centimeter
wall thCckness

material

=cv)x

n~~e;;.~er

Next,
multiply
the length
of the longest
wall
in meters
The answer will
be the number of sq. meters
in the wall.
figure
in the correct
place
in Equation
2:

its height.
Enter
this

Equation 2
Weight of
longest wall

weight

of 1 sq. meter
of wall

of sq.
in longest wall

of the longes t wall
based
2 in steps 2 (c) and 2(d).

the weight
in Equation

Estimate
STEP 3.
longest wall.
Equution

the weight

of the

roof

on the

fi gures

supported

you

have

by the

1
weight of longest
wa:.l (kg)

Weight Per
sP=e .meter

(a)

length

of longest

till

(m)

Use the following
equation
to
estimate
the weight
of the roof
supporeed
by the longest
wa9 1:

We*t

roof

szgported by
longest watt
(b)

t&ght
of roof
per sq. meter

Use Table
6 to find
the estimated
weight
of the roo.f per sq. merer.
If you are in doubt about
the
roof-style
planned,
use the
figure
on the table
for flat
Enter
the figure
you
roofs.
find
in fable
B in Equation
3:

Equatimr3
Weight of
mof
supported by =
longest 7x111

nwnberof
sq.
meter8
in. mop

Table
Roof Style

Roof load
per sq. m

pitched

1707cg

flat

19okg

205
(c) Next,
multiply
the length
of the roof
If the roof has not
by its width.
been planned
yet,
assume that
it wi 11
be 1 meter longer
and I meter wider
The answer will
than the building.
be the number of square meters
in the
Enter
this
figure
in the
roof.
correct
place
in Equation
3:

Equation

Weight of

roof

weight of roof
= per sq. meter

supported by
longest waZ.1

(d)

Compute
figures

the weight
of roof supported
you have entered
in Equation

by the longest
wall
3 in steps
3(b) and

using
3(c).

the

STEP 4. Enter the figures
you calculated
in steps 1, 2(e),
3(c) in Equation
1, and calculate
the weight of the building
square meter:

Equation

and
per

lFrom 3(c)
From 2(e) :

weight

STEP 5. Finally,
compare the
building's
weight per square
meter
with the weight-bearing
capacity
of the soil at the
site indicated
in Table C.

of longest

weight of-&of
supported by

TabZe C
Weight-Bearing
Type of SoCl
Cupacitg (kg/sq.
soft, b&z&,
&Sned marsh,
or t'filllr
GraveZ, sand
Hard-packed clay
Rock

4,9OU-10,000
29,400
58,800
156,800

206
8.7m

SZQYPLECALCULATION OF A BUILDING'S

WEIGHT PER SQUARE METER

Here is a step-by-step
sample of how the weight of a building
would be estimated,
following
the procedure
outlined
on pages
202-205.

Assume that the building
pictured
above is planned to be 7.5
wall;
assume
meters long and 2.4 meters high along its longest
also that the walls will
be made of 20cm thick
sand-cement
blocks,
and that the roof will
be 8.7 meters long and 3 meters
wide, with a pitched
design.
If the site selected
for the
building
is soft,
dark soil that can support 4,900 kg/sq.
meter,
can the building
be constructed
as planned?
Here are the

calculations:

-Equation 1
Weight per
square meter

weight of longest
wall (kg)
=
length

STEP 1.

Enter

Equation

the length

of longest

of the longest

weight of longest
wu1.l (kg)

=
(SE]

nail

wall

Weight per
square meter

weight of roof
supported by
longest wall (kg)

in Equation

weight of roof
supported by
longest watt (kg)

‘+ /
:,~.
I’

207

STEP 2.
(a)

Calculate

Use Equation

Equation

the weight

Use Table
centimeter

wall.

A, page
of wall

weight

to find
thickness.

203,

t4;4;Lply
the figure
. The result
this
answer
in the

of 7 sq. meter
X

of wizzz

the

wall’s

weight

number of sq. meters
in longest wall

per

square

will be made of sand-cement blocks
meter for every centimeter
of wall

Yae build&g's
walls
says weigh 75 kg/sq.
(c)

longest

Weight of
longest wall

(b)

of the

meter

for

which Table A
thickness.

you find
in Table A by the thickness
of the
will
be the weight
of 1 square
meter ,of wall.
correct
place
in Equation
2.

building’s
Enter

!l%e sand-cement blocks that will be used will be 2Ocm thick.
So a
wall made of these blocks will weigh 75 kg/sq. meter x 2Ocm thick
1500 kg/square meter.
Entering

this

answer in Equation

Weight of
longest till
(d)

2:
x nzunber of sq. meters
in longest wall

Multiply
the length
of the longest
wall
in meters
enter
the result
in the correct
place
in Equation

by its
2.

The longest wall of the building
will be 7.5 meters
meters high.
7.5 x 2.4 = 18 square meters.
Enterixg

this

answer in Equation

Weight of
longest wall
(e)

Compute
entered

the weight
in Equation

height

and

long and 2.4

1500 kg/sq.

meter

x (,,.)

of the longest
wall
based
2 in steps
2(c) and 2(d).

on the

figures

every

you

have

1500 kg/sq. meter x 18 sq. meters = 27,000 kg. Entering this result
in EQuation 1:
weight of roof
+ suported
by
Q5G-G)
Weight per
Zongest wall (kg)
square meter =
\7.5 meters

208

STEP 3. Estimate
longest wall.
(a)

Use Equation

the weight

of the

roof

supported

by the

Equation3
Weight

of
=

POOf

supported by
longest wall
(b)

might of roof x nwnber of
per sq. meter
sq. meters
in roof

Use Table
B, page 204, to
Enter
this
figure
meter.

The zvof is pZmrned with
about 170 kg/%q. mter.
Entering

this

find
the estimated
weight
of the
in the correct
place
in Equation

a pitched

answer in Equation

roof

that

roof

per

square

Table B says will

weigh

Weight of
nwnberof
sq. meters
in roof

mof

supported by
Zongest wall

(c)

Multiply
the length
of the roof by its height
to
meters of roof space planned.
Enter
this
figure
Equation
3.

find
the number of square
in the correct
place
in

The roof is plunned to be 3 meters with and 8.7 meters
3mx8.7m
= 26.1 square meters.
&teting

this

answer in Equation

long.

Weight of

roof

170 kg/sq.

meter

6.1 square

meters

supported by
longest wall

(d)

Compute
figures

the weight
of roof supported
you have entered
in Equation

170 kg/sq. meter x 26.1 sq. meters
result
in Equation 1:
Weight per
square meter

27,000 kg
=

by the longest
wall
3 in steps 3(b) and

4,437 kg.

(TEEiks)

7.5 meters

using

the

3(c).

Entering

this

209
STEP 4. Calculate
using the figures
Equation
1.

the weight of the building
per square meter,
you calculated
in steps 1, 2(e), and 3(c) and

27,000 kg + 4,437 kg

7.5 meters
The building

31,437 kg

4,191 kg/sq.

meter

7.5 m

WiZZ weigh approximatedty

STEP 5. Compare the building's
with the weight-bearing
capacity
Table C, page 205.

4,191 kg/sq.

meter.

estimated
weight/square
meter
Use
of the soil at the site.

According to Table C, the weight-beating
capacity of the soft, dark
Since this building
will
soil at thCs site is 4,900 kg/sq. meter.
can be built safely at
weigh only 4;191 kg/sq. meter, the building
th$s site.

To determine
whether the soil at any proposed site will
support
all the builder
needs to do is substitute
a planned building,
the figures
for his/her
building
and site in the step-by-step
equations
on pages 202-205, as shown.

2. STEP-BY-STEP

QIRECTIONS

FOR

DRAWING

FOUNDATION

Two kinds of drawings are important
aids to help the field
worker and community members visualize
their
foundation
plans
and check their
progress
during construction:
l

a cross-section
wall:
and

view

of the footing

a view from above of the footing
measurements,

and foundation
and foundation

wall

When a community group is ready to begin construction
of the
foundation,
it's
a good idea to help them build a small
demonstration
section
of footing
and foundation
wall that they
can use along with these drawings to check their
progress.
The
demonstration
section will
help everyone see what they have
planned to do; at the same time, it will
give them practice
in
the construction
techniques
and skills
Lney must use on the
aktual
foundatfm.
DRAWING A CROSS-SECTION VIEW OF THE FOUNDATION
Drawing a cross-section
view of the foundation
is simple.
Here
are examples of a cross-section
for a rock foundation
and for
a block foundation
wall.
Roth drawings
show concrete
footings
as well:

:. a*
.*. .

ROCK FOUNDATION WALL

- -‘.

FOOTING
* v
0 .
J
BLOCK FOUNDAT I ON WALL

PUANS

211

DRAWING FOOTING AND FOUNDATION MEASUREMENTS (VIEW FROM ABOVE)
Drawing the foundation
measurements
as they would look from above is
also simple.
Here are step-by-step
instructions
for drawing the foundation
measurements of a sample building:

Draw a solid
line representing
the outside
dimensions
of the
This
walls of the building.
line will
also represent
the
outside
dimensions
of the
foundation
wall.

Draw a second solid lineimide
the first
one to represent
the
inside dimensions
of the
This line
building's
walls.
will
also represent
the inside
dimensions
of the foundation
The space betueen the two
wall.
lines should be exactly the width
the plumed &!ZG to scale.

(OUTS

INStDE

WALL b

(WIDTH

I DE WALL

OF WALL

Subtract
the width of the wall
from the planned width of the
Divide the
foundation
footing.
remainder
in two and convert
the answer into the scale
dimension
being used in the
This figure
represents
drawing.
the distance
between the inner
side of the wal! and the inner
side of the fou dation footing.

Draw a dotted line inside
the
This line
drawing of the walls.
represents
the inner dimension
The space
of the footing.
between it and the inside
solid
line
(step C2) should
be exactly
the distance
calculated
in step #3,

Draw a dotted
line outside
the
This Pine
drawing of the walls.
represents
the outer dimension
of the footing=.
The space
between it and the outside
solid line
(step #l) should
be exactly
the distance
calculated
in step R3.

Ii
,.

OUTS I DE EDG.E
OF FOOTING

213
0

r
I

On either
side of the
drawing's
length, add a
solid
line exactly
as long
as the longest wall
(that
is, the longest outer
solid
line).

On either
side of the
drawing's
width , add a
solid
line exactly
as long
as the longest wall
(that is, the longest
C
outer solid
line).

MARK D I MENS IONS CALCULATED I N
THE CIRCLES ON THE DRAWING

7!
I
I
I
I
I
I
I
I
I
I
I
I
I
-I ----------

------a--

-------- -,J
A-

Place a mark
along each line
from steps #6-7
wherever the
outer wall turns
a corner.
Indicate
the
actual
length
of each
straight
section
of wall.

MARK DIMENSIONS CALCULATED IN
THE CIRCLES ON THE DRAWING

-c
I
I
I
I
1

i
i
I
I
1
I
I
-4

---------------II
1
I
!---------------

1
3

II
I
I

t
I
I
I
I
I
f

214

Outside the lines drawn in steps #6-7, draw two more solid
lines exactly
as long as the length and width of the outer
dotted line.
Mark these lines to indicate
the actual
length
of each straight
section
of foundation
footing.

10. Underneath
the completed
and foundation
wall will
dimensions.

drawing,
write
down what the footing
be made of and their
cross-section

11. The completed drawing is an actual
scale drawing showing
the trenches
that must be dug for the footing
and the
dimensions
of the foundation
walls.

Completed

foundation

plans:

215
3. ESTIMATING

THE AMOUNTOF

CONCRETE

To estimate
the following

the amount of concrete
equation
and table:

needed

NEEDED

for

a floor,

FOR A FLOOR

use

Equation.
Cubic meters of
concrete needed
for floor

Table.

thickness of
concrete
Zuyer (ml

floor

area

(sq. meters)

SUGGESTEDTHICKNESS OF CONCRETEFLOORS
Purpose of Floor
School,

STEP 1.
used for
Equation:

Find
your

Clinic,

Thickness

House

.lOO

Garage (for

vehicles)

.I25

Farm storage
equQmwnt)

(heavy

.150

the thickness
of the concrete
building
in the table,
Enter

Cubic meters of
needed

for
concrete
floor

STEP 2, Multiply
the length of your
building
by its width to find out what
floor
space it will
have.
Enter this
figure
in the Equation:
Cubic meters of
concrete needed
for floor

concrete

(ml

layer that
this figure

should be
in the

216
/

In cases where the building
will
not
be a simple rectangle,
the total
floor
area can be determined
by
multiplying
the length and width of
each separate room and then adding the
areas of all rooms together.

Sample CaZcuZation:
Floor
FZoor
Floor
Tote,'

area Room 1 = 2m x 2.Om = 4.0 sq.
area Room 2 = lm x l.Sm = 1.5 sq.
aTea Room 3 = lm x l.Om = 1.0 sq.
_PZoor Area =
6.5 sq,

m
m
m
m

In round buildings,
the floor
area
will
be the radius of the building
squared times 3.14.
The radius is
the distance
from the outside
of a
circle
to its center.
Sampi!e Calculation:

Floor Area = Radius

(2m) x Radius

i2m) x 3.14

= 4 sq. meters x 3.14
= 12.56 sq. meters

STEP 3. Enter the answers you found in steps 1 and 2 in the
Equation and multiply
them.
The answer will
represent
the number
of cubic meters of concrete
that must be purchased or made for
the floor.
Swnpte Calculation

(u&g

Cubic meters of
concrete needed. =
for floor
.

figures

for round cI.inic

thickness of
concrete
x floor
layer
(rn)

.lOm

1.256 cubic meters

shown above)

area (sq. meters)

12.56 sq. meters

217

4. ESTIMATING

MATERIALS

NEEDED

This section
gives step-by-step
directions
for calculating
the
materials
needed to build three
poured concrete,
types of wall:
and brick/block.
rammed earth,

TO BUiLD

WALLS

POURED CONCRETE/RAMMED EARTH FORM

POURED CONCRETE AND RAMMEDEARTH
To deter-mine how much poured
concrete
or rammed earth he/she
must calculate
needs, the builder
how many cubic meters of material
it will
take to "fill"
the wall
space.
Use the following

equation:

Equation.
Cubic meters of
nnterial
needed
fi3i

one wall

thickess
of
watZ (meters)

x waZZ area Isq. meters)

STEP 1. Decide how thick the wall will
be (see page 94 for a
discussion
of what to consider
when planning
wall thickness).
Enter this figure
in the correct
part of the equation.
STEP 2. Calculate
the,wall
area in square
the wall's
Length by its width.

meters

by multiplying

STEP 3. Multiply
the answers you found in steps 1 and 2. The
result
will
be the cubic meters of crncrete
or rammed earth you
will
need to build
that one waZ2.
STEP 4. Repeat

steps

1 through

3 for each wall of the buitding.

STEP 5. Add the cubic meters of concrete
or rammed earth needed
The result
will
be the tot&
for all the walls of the building.
number of cubic meters of concrete or rarrPned earth you will need for the
buitdzng.

218

Calculating

Baqs of Cement Needed for

a Concrete

Wall

Builders
who plan to purchase the cement for their
concrete
need
Once you have
to know how many sacks or bags of cement to buy.
determined
how many cubic meters of concrete
you will
need,
finding
the number of bags of cement is easy: just look the
To use the table,
answer up in Table 3, in Appendix 4 (page 222),
In the case of
find the concrete
mixture
you plan to use.
first,
The table will
then tell
the mixture would be 1:2 3/4 :4.
walls,
you how many cubic meters of concrete
you will
get from one sack
Divide the number of cubic meters of concrete
you plan
of cement.
The answer will
to use by the amount you would get from one sack.
be the number of sacks of cement you need to purchase.
Calculating

Wheelbarrowsful

of Rammed Earth

or Concrete

Needed

Hanybuilderswant
to know how many wheelbarrows
full
of concrete
or rammed earth they must bring to the construction
site for
wall construction:
this information
gives them an idea of how
much work will
be involved.
The number of wheelbarrowsful
these steps:
0 Build a form exactly
many wheelbarrowsful
to fill
the form.

needed can be estimated

by following

1 cubic meter in size and count how
of rammed earth or concrete
it takes

. Multiply
this number by the total
cubic meters of material
that are needed for construction
(from Step 5, page 216).
Your answer will
tell
you how many wheelbarrowsful
are
needed,

BLOCK AND BRICK WALLS
To estimate
the number of blocks
bricks
needed to build a wall,
follow
these steps:

or 1,

STEP 1. Calculate
the wall area
in square meters by multiplying
the
wall's
length by its tvidth.
STEP 2. Note down the nominal size
of the block face.
The nominal face
of a block is the height and length of
the block surface visible in the watt
after

the block

is laid.

219
STEP 3. Use the table below to find how many blocks or bricks
1 square meter
of the size you plan to use are needed to build
of wall surface.
APPROXIMATENUMBEROF BLOCKS OR BRICKS REQUIRED
TO BUILD 1 SQUAREMETER WALL SURFACE
Number of
Blocks or Bricks
Needed

Nominal
Size of
_Face (em)
7.5
10.0
13.25
15.0
20.0
15.0
20.0
15.0

x
x
x
x
x
x
x
x

20
30
30
30
30
40
40
60

65
32.5
25
22
16.5
16,s
12.5
12

STEP 4. Multiply
the number you found in the table by the number
of square meters of wall surface you found in step 1. The result
will
be the approsimate number of blocks or bricks
needed to build
the wall.
Sample Calculation:
How many blocks would it take to build a wall with 17
square meters surface area using blocks with a nominal
face 15cm x 3&m?
The table

shows that

22 15cm x 3Ocm blocks

are needed to

build 1 square meter of wall mea.
17 sq. meters

22 btocks/sq,

meter

374 blocks

STEP 5. Repeat steps 1 through 4 for each wall of the building
and add the results.
The total
will
represent
the number of
blocks or bricks
you must buy or make for the walls.
Note: Any estimate
of the number of blocks/bricks
needed for
a building's
walls arrived
at through this method will
include
extra blocks,
since the space taken by window and door openings
is treated
as though it were filled
in with blocks.
Generally
it is a good idea to buy or make these extra blocks.
This will
give you a margin of error
for wasted or broken blocks.

Calculating

Mortar

Quantities

The amount of mortar needed to bond the blocks/bricks
for a
building
depends on the number of blocks/bricks
and their
size.
To calculate
the amount of mortar needed for Icm thick
mortar joints,
follow
these steps:
Divide
l

the number of blocks needed
For example, if the building
1536 + 100 = 15.36.
100.

for the building
by
requires
1,536 blocks,

Use the table below to find the cubic meters of mortar
needed to lay 100 blocks.
For example, if the nominal
size of the blocks used will
be 1Ocm x 20cm x 40cm,
.073 cubic meters of mortar would be needed to lay every
100 blocks.
Multiply
the answers found in the above steps.
For
example, if 1,536 blocks of nominal size 1Ocm x 20cm x 40cm
are needed for a building's
walls,
multiply
15.36 x .073.
15.36 x .073 = 1.12 cubic meters of mortar.
Table 7 in
Appendix 5 (page 224) may be used to determine
how much
cement, lime, and sand yo;l will
need to make the mortar
required
for any building.

(Mortar

QUANTITIES OF MORTARREQVImD
TO LAY 100 Bs!X'WSfBRIC~
for Joints lcm Thick Includhag 25% Alhxznce

Nom-hat Siie of
BlOCks/B2+&3
(Cd
10 x 13.25
15 x 13,25
20

10
15
20

10
15
20
25
30
15

x 30
x 30
x 13.25 x 30
x 15
x 30
x 15
x 30
x 15
x 30
x 20
x 30
x 20
x 30
x 20
x 30
x20

x
x
x
x
x
20 x
25 x
30 x

20
20
20
20
15
15
15
15

x
x
x
x
x
x
x
x

40
40

40
40
40
60
60
60
x.60

cubic Meters
of
Miwtar
.053
"053
,067
,065
,065
,070
,061
,061
,076
-073
-073

.og2
,092
l 092
t 092

.r15
,115
,115

for

Waste)

rXI

221

5. REFERENCE

TABLES

FQR

Recommended

CONCRETE

TABLE 1
Thickness
of

CONSTRUCTION

Concrete

Basement floors
for dwellings
Porch floors
Stock barn floors
Poultry
house floors
Hog house floors
Milk house floors
Granary
floors
Implement
shed f loot-s
Tile
floor
bases

Quantities

Materials
(for

Mixtures
1:1:1*
1:1:2
1:1:23

1:1:3
1:1$:2
l:lf:3
1:l 3/4:2
1:l 3/4:2t
1:l 3/4:2
1~2~3
1:2:3&
1:2:4
1:2:5
1:2%:23
1:2+:3
1:2&:4
1:2%:5
1:2&:3
: 3. .
1;2&4&
1:2f:5
1:2 3/4;4
1:3:4
1:3:5
1:3:6

3/4

Slabs

(cm)

10
10-12.5
12.5-15
10
10
10
12.5

15
6.25

TABLE 2
Required
to Build
One Cubic Meter of
Aggregates
2.5 Centimeters
or Less)

Barrels
of
Cement

Cubic Meters
of Sand

3.56
3.23
2.90
2.64
3.04
2.44
2.75
2.64
2.44
2.24
2.07
1.95
1.73
2.32
2.18
1.31
1.68
2.11
1.98
1.82
1.82
1.62
1.74
1.66
1.49
1.36

.40
-36
.33
.30
.43
.42
.54
.51
.47
.50
.48
.44
.39
.59
055
.48
.42
:Z
.51
.48
.46
.54
056
.51
746

Concrete

Cub i c Mete rs
of Stone

.60
2:
.83
.68
.84
.62
.67
.80
237
.88
25
.74
.86
.94
l 71
::2"
.87
.91
-79
-75
.84

.92

222
TABLE 3
Volume of Concrete
Construction
for Aggregates
Not Larger
than
Concrete
Mixtures

Cubic Meters
Per Sack of

l:l:l$
1:1:2
1:1:2f

1:1:3
1:1&:2

l:lf:3
1:l 3/‘+:2
it1 314~2%
1:l

3/4:23/4

1:2:3
1:2:33
1:2:4
1:2:5

of Concrete
Cement

Concrete
Mixtures

.07
.08
.03
.lO
.08

1:2*:23
1:2&:3
1:2&:4

Cubic Meters
Per Sack of
10
:l?

1:2&:3

.12

13
:14
l5
:15
.14
.14
17
:18

.lO

1:2+:4

10
:10

1:2+:5

l:2*:4i
1:23/4:4
1:3:4
1:3:5
1:3:6

for

TABLE 4
Various
Concrete

Construction
Concrete

Floors
. One Course
. Heavy Duty, One Course
. Farm Buildings
Foundation
Walls and Footings
Basement Wa11,s
Tanks
Fence Pos t s
Retaining
Walls
Ba rnya rd Pavements
Lintels
Beam Filling
Silo
Pits
Steps

of Concrete
Cement

13
:15

l 03

Mixtures

Sack of Cement
Centimeters)

1:2%:5
1323333

.ll
.12
13
:14

Suitable

per
2.5

1-:1 3/4:4
1:1:2
1:2%:3

1:23/4:4
1:23:4
1:2:3
l:l:l&

1:2:3f
1:3:5

1:2:4
1:3:4

1:2t:3
1:2t:3

Projects
Mixture

,:-,3: “_
>s ”
,
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Modify Date : 1999:10:07 08:11:57
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Self Help Manual Of 1 Story Buildings

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