the good and the bad infrastructure books (edition 4) - housing construction

SETTING OUT - FOUNDATION - CONCRETE WORKS - WALLS - ROOF - FLOOR - SERVICES

I N F R A S T R U C T U R E

Author :Ekart Hartmann dan Heinz Unger

Editor :Octaviera Herawati

Photos by :Ekart Hartmann

Published by :World Bank Office, JakartaPNPM Support Facilities (PSF) OfficeJalan Diponegoro No. 72Jakarta 10310Phone : (62-21) 3148175 (hunting)Fax : (62-21) 31903090Website : www.worldbank.org

All, or any part of this book may be reproduced for training needs

For Further information, please contact :Octaviera HerawatiPhone : (62-21) 3148175Fax : (62-21) 31903090Email : [email protected]

i

THE GOOD & THE BAD INFRASTRUCTURE

INTRODUCTION

Housing Construction

Indonesia has experienced a number of natural disasters in the recent past that have dam-aged or destroyed large numbers of residential housing. Major reconstruction efforts by local, national and international agencies were initiated, and because of many homeless families, speedy completion was an important factor.The need for speed can sometimes lead to low quality workmanship. However, it has been shown that poor construction techniques waste materials, time and efforts; they may make the house uncomfortable, and at the worst, may cause the structure to be unsafe. Costly repairs and early replacement are serious consequences of poor construction practice.On the other hand, good quality housing makes for happy occupants, and has important economic benefits in terms of a longer lifespan and savings in materials and construction costs. If a house is well built, the owners are also much more likely to make further invest-ments in expanding and improving their basic core houses.A lot has been learned in the many recent reconstruction projects, in terms of both, good and bad examples of house construction. While the bad examples are obvious and speak for themselves, the good examples show how much can be achieved by making serious efforts, using good experience, common sense and some technical training.Considering the above mentioned, this book is made to complete the existing standard manual for housing that have been published by the government or other institution. The book presented is simple and easy to understand because each picture are complimented by simple explanation.

It is also hoped that the book will be used not only for disaster reconstruction programs but that housing construction in general will benefit from the good and bad practice ex-amples that are being presented. The book is intended not only for builders, contractors and their technical staff, but should also be perused by bureaucrats, managers, staff of mul-tilateral and bilateral assistance agencies, international and Indonesian NGOs active in the housing and community sectors, and lastly but not least, the beneficiaries themselves.Hence, the book should be distributed widely and should be made available to all who ask for a copy; it could also be adapted for training in house construction.

ii


AKNOWLEDGEMENTS

Scott Guggenheim who had the original idea and arranged the funding, Ekart Hartmann (with help from Heinz Unger) who prepared the technical pages, Octaviera Herawati who managed the efforts (including coordination of inputs, management of production un-til publication, and also the translation into Bahasa Indonesia), the many technical staff who provided reviews and suggestions, such as Saleh Siregar, Purnomo Sutantyo, Eka Hasfi Adha, Festina Lavida. Special thanks to Victor Bottini and Sentot Satria who keep support-ing this book. Also the layout artist and printing company, and anybody else, including admin and support staff who may have done a lot of work ……..

Contents

INTRODUCTION iAKNOWLEDGEMENTS ii

BAD GOOD

SETTING OUT Setting out 1 3

FOUNDATION Excavation 7 8

Rock 10 14

Concrete 19

CONCRETE WORKS Concrete Production 21

Formwork 23 30

Reinforcement 41 53

Beams, Columns 66 75

Slab 82

WALLS Materials 83 84

Construction 85 93

Windows & Doors 97 99

Plaster 105

ROOF Roofing materials 107 109

Aluminium 112 113

Wood 116 121

FLOOR Construction 131

SERVICES Electricity 135 138

Water & Sanitation 139 140

12 Important Rules


Setting OutChapter 01

1Chapter 01 Setting Out BAD


Setting out

Rubbish and rotting plants not removed

Boards without straight edges

Clean up site before setting out

How can I do it better ?

• Itiseasiertofixthefloorlevelwithstraight-edgedboards• Beforestartingtheexcavationthesiteshouldbecleanedup• Organicmaterialwillrotandmakeabadfoundation

Why ?

• Organicmaterialwillrotandthegroundwillsettle• Wastemightbecontaminated

2 Chapter 01 Setting OutBAD


Setting out

Dispose of plants andwastefirst

Rottenplantsandwastearenotagoodbaseforfloorconstruction


• Thesiteshouldbecleanedupbeforestartingtheexcavation

Why ?

• Organicmaterialwillrot,andthegroundwillsettle• Wastemightbecontaminated


3Chapter 01 Setting Out GOOD

Setting out

Clear ground of all plants and rubbish

Setting out workarea

Markouttheboundariesoftheconstructionarea

Why is it better ?

• Plantsandotherorganicmaterialwillrotandcausethegroundtosettle• Setupboardsaroundthebuildingoutlineandleaveaworkingspaceofatleast

1m

Alternative:

• Thereisnoalternativetosettingoutproperly


4 Chapter 01 Setting OutGOOD

Setting out

Boards set at plannedfloorlevel

Stringsmarkthelocationoffoundations

Stringsfixedwithnails on the board

Setoutthestringsaccordingtothedesign of building

Why is it better ?

• Tautstringsformastraightlinefromwhichallmeasurementscanbemade• Setthetopoftheboardslevelwiththefinishedfloor• Straight-edgedboardshelptodefinethefloorlevel-useaspiritlevel

Alternative:

• Insteadofstrings,thelinescanbemadeofchalk,buttheywouldgeteasilycoveredupifearthorconcreteisdumpedonthem

• Thereisnoalternativetosettingoutthestructureproperly


5Chapter 01 Setting Out GOOD

Setting out

Intersectingstringsshowthecenterofcolumns

…butstringscanalsomarkcenterlinesoffoundations

Stringscanmarkthe width of the foundation…

Theaboveexamplesshowtheimportanceofstringsinmarkingallimportantpointsandlinesofthestructure

FoundationChapter 02

7Chapter 02 Foundation BAD


Excavation

No boards for strings

Roots of plants not disposed of

Trenchistoo shallow

Bottom of trench has to be levelled


• Startwithit-Settingoutthetrenchalignmentandtrenchbottomandtopwithboardsoneachsideofthesite–startwithit

• Beforestartingtheexcavationthesiteshouldbefreefromallorganicmaterialand waste

• Foragoodfoundationaminimum70cmdeeptrenchisrequired

Why ?

• Organicmaterialwillrotandcausethegroundtosettle• Adeeptrenchfoundationmakesasolidbaseforthehouse

8 GOOD Chapter 02 Foundation


Excavation

No boards for strings

Roots of plants not disposed of

Trenchistoo shallow

Trenchesthathavebeenexcavatedforfoundations

Why is it better ?

• Trenchisstraightandhasslightlyslopedwalls• Trenchisdeepenoughforthesubsoilatthesite–aminimumof70cm

Alternative:

• Thereisneveranalternativetogoodandcleanexcavation

9GOODChapter 02 Foundation


Excavation

Depth depending on soil at the site

Excavatedmaterialcanbeusedunderfloor

Boards for setting out strings

Trenchforfoundation

Why is it better ?

• Trenchisstraightwithslightlyslopedtrenchwalls• Trenchisdeepenoughforthesubsoilatthesite–aminimumof70cm

Alternative:

• Thereisneveranalternativetoagoodexcavationofthefoundations

10 Chapter 02 FoundationBAD


Rock

Foundationtrenchistoo shallow

Notenoughconcretebetweenrocks

Bottomrocklayernot embedded

Rock layer of foundation is not embedded in concrete


• Deepenthetrenchtogetabetter,moresolidbaseforthefoundation• Therockshavetobeembeddedinconcrete• Foragoodfoundationaminimumof70cmdeeptrenchisrequired

Why ?

• Adeepfoundationtrenchmakesasolidbaseforahouse



Rock

Foundationtrench

Bottomrocklayer–should not be in a straight line

Bedforrocks

Strings from setting out

Bottomrocklayerintrench


• Rocksaresettoomuchinastraightline–theyshouldbeplacedrandomly

Why ?

• Thereisneveranalternativetosolidfoundationmaterial

12 Chapter 02 FoundationBAD


Rock

Notenoughconcretebetweenrocks

Firstrocklayernotembedded

Foundationtrenchtoo shallow

Rocklayeroffoundationisnotembeddedinconcrete


• Deepenthetrenchtogetasolidbaseforthefoundation• Therockshavetobewell-embeddedinconcrete• Forasolidfoundationaminimumof70cmdeeptrenchisrequired

Why ?

• Adeepfoundationtrenchmakesasolidbase



Rock

Crackcausedbysettlement of the foundation

Movement of foundation

Acrackistheconsequenceofpoorlycompactedsubsoilorapoorfundationgenerally


• Theexcavationofthetrenchbottomforthefoundationandtheconstructionofthefoundationitselfhavetobecarriedoutwithgreatcare.

• Rocksinthefoundationhavetobewell-embeddedinconcrete

Why ?

• Adeepfoundationtrenchmakesasolidbaseandreducesthechanceofgroundsettlements.



Rock

Movement of foundation

Rocksforfoundation

Why is it better ?

• Rockshavetointerlockeachother• Rocksofdifferentsizefilltheremainingspacesbetweenbigrocks• Rockscarrytheloadofthehouse

Alternative:

• There’sneveranalternativetosolidfoundationmaterial



Rock

Roughsurfacefortoplayer

Toplayerofconcrete–levelled

Layersofrocksembeddedinconcrete

Sand or lean concretelayer

Strings for setting out

Allphasesoffoundationconstruction

Why is it better ?

• Sandorleanconcretestabilizetherocksonthetrenchbottom• Rocksarewell-embeddedinconcrete• Toplayerlevelsthefoundationtop• Roughenthesurfaceofthetoplayerforbetterbondwiththeconcreteofthe

foundation beam

Alternative:

• There’sneveranalternativetoasolidfoundation



Rock

Foundations

Spaceleftforsetting out the reinforcementofthecolumn

Foundationmeetsfoundation

Why is it better ?

• Rebarsofthecolumnhavetosetbeoutbeforelayingtherockfoundation• TheremustbeenoughspaceforL-shapedbottomendofrebars

Alternative:




Rock

Spaceleftforsettingoutthereinforcementofthecolumns

Height of foundations accordingtotherequirementsofthelocation–water,terrainetc

Spaceleftinfoundationforcolumns

Why is it better ?

• Rebarsofthecolumnhavetobesetoutbeforelayingtherocksofthefoundation

• TheremustbeenoughspaceforL-shapedbottomendofrebars• Thehigherthefoundationthelowertheriskofwaterdamage

Alternative:




Rock

Waterresistantcementforconcrete

Roughenedsurfaceoftoplayer

Awell-builtstripfoundation

Why is it better ?

• Concretewithwater-resistantcementavoidsmoistureinthewall• Awell-madefoundationisthebestbaseforabuilding• Roughsurfaceoftoplayerenablesbetterbondtobeams

Alternative:




Concrete

Singleconcretefoundation

Foundationtrenchfilledwithrocks

Strings of Set Out

Single foundations instead of stripfoundation

Why is it better ?

• Singlefoundationforcolumnsareasolidbaseforelevatedfloorslabs

Alternative:

• Stripfoundationisanalternative• There’sneveranalternativetosolidfoundationmaterial



Concrete

Rebars have to be supported

Filledupwithstonemasonry

Heightacc.torequirements

Individualfoundations

Individualfoundationsforelevatedfloorslab

Why is it better ?

• Individualfoundationsforcolumnsareasolidbaseforthem• Thestonemasonrysupportsfoundationbeams• Neatappearanceofthemasonrywork

Alternative:

• Stripfoundationisnoalternativeforelevatedfloorslabs• There’sneveranalternativetosolidfoundation

Concrete WorksChapter 03

21Chapter 03 Concrete Works GOOD


Concrete Production

Cement Sand Gravel

Water

Good quality concrete beams

Why is it better ?

• Thequalityofconcretedependsonthecorrectproportionsofallingredients,i.e.cement,sand,aggregatesandwater.

• Notenoughcementinthemixmakesweak,lowstrengthconcrete• Toomuchwateralsomakespoorqualityconcrete• Itisimportanttomeasureandaddgravelandsandseparatelyformakingdense

concreteofgoodquality

Alternative:

• Thereisneveranalternativetogoodqualityworkmanship.

22 Chapter 03 Concrete WorksGOOD


Concrete Production

Measure&mixtheingredientswithcare

Lettheconcreteslipintotheformwork

Why is it better ?

• Goodpreparationisessentialforgoodconcrete• Donotdroptheconcreteintotheformworkfromanyheight,butletitslip• Maximumdropofconcreteis5m,otherwisetheaggregatesgetseparated• Avoidcoldjointsduringpouring-doonesectioninonelift

Alternative:

• Thereisneveranalternativetogoodqualityworkmanship

23Chapter 03 Concrete Works BAD


Formwork

Formworknotparallelto rebars

Rebars are in a straight line

Coverof1–2cm

Watchthatconcrete“cover”isthesameoverentirelength


• Keepthedistancebetweenrebarsandformworkconstant(minimalcover2cm)• Usecontinuousformwork• Fixthebottomedgeofformworkboardtokeepitstraight

Why ?

• Thestrengthofreinforcedconcretedependsontheproperinstallationofrebarsandformwork

24 Chapter 03 Concrete WorksBAD


Formwork

Distanceof2cm

Distanceofspacer

Distance(cover)of2cm

Spacer(blocks)underrebarskeeptherightdistancetotheformwork


• Usespacer(suchasacementblock)tokeep“cover”distancebetweenrebarsandformworkconstant(2cm)

• Supportbeamformworkevery50cm

Why ?

• Spacersareessentialforensuringthecorrectandconstantconcretecover• Thestrengthofreinforcedconcretedependsontheproperinstallationofrebars

andformwork



Formwork

Distancefromrebarstoformworkistoolarge

Rebartouchesformwork

Spacer(block)onrebarswouldkeepthecorrect“cover”distancetoformwork


• Usespacerblockstokeepdistancebetweenrebarsandformworkconstantfrom2cm

Why ?

• Therewillbenoconcretecover,i.e.thesteelbarswillbeexposed,whentherebarstouchtheformwork

• Spacersareessentialtoensurecorrectandconstantconcretecover• Thestrengthofreinforcedconcretedependsontheproperinstallationofrebars

andformwork



Formwork

Theremustbeaconnectionbetween these beams

Cutoffformworkbeforeconcreting

Thetwoconcretebeamsmustbecontinuous,includingtherebars


• Cutopentheformworkbetweenthetwobeamssothattheyarecastasoneconnectedstructure

Why ?

• Jointsarealwaysaweakspotintheconcrete• Beamsuptoalengthof5mcanbecastinonepour



Formwork

Beamsupportevery50cmBeam supports are essential before concretingtheadjacentsection

Supportroofridgeandformworkforbeamfirst,thenstartconcreting


• Supportformworkofconcretebeamsevery50cmuntilconcretereachesitsfullstrength

• Supportreinforcementbeforepouringtheadjacentsection

Why ?

• Duringpouringtherebarsmustnotmovednorvibrated



Formwork

PourthebeaminoneliftSupport needed here

Avoidconcretinginshortsections


• Solidlybuiltformworkisthebasisforstrongconcretestructures• Supportformworkofbeamsat50cmintervalsuntilconcretereachesitsfull

strength• Whencastingbeams(orcolumns)placeconcreteinonelift

Why ?

• Avoid“cold”concretejointsasmuchaspossible• Jointsarealwaysweakpointsofanyconcretestructure• Beamsuptoalengthof5mcanbecastinonepour



Formwork

4sections!

3sections!

Cast all concretebeamsandcolumnsalwaysinonelift

Avoidpouringconcreteinshortsections


• Solidlybuiltformworkisthebasisofgoodconcretestructures• Placeconcreteforallbeam(andcolumns)inonepour(lift)

Why ?

• Avoid“cold”concretejointsasmuchaspossible• Jointsarealwaysweakpointsinanyconcretestructure• Beamsuptoalengthof5mcanbecastinonepour



Formwork

Distanceofbracketstobemax.80cm

Plywoodsheet Timber(wooden)supports

Tiebrackets

Formworkforcolumnsshouldbebuiltlikethis

Why is it better ?

• Bracketstietheplywoodsheets(orboards)oftheformworktogether• Thespacingbetweenbracketsshouldbebetween50cmand80cm• Formworkshouldbeatleast2cmthick• Well-builtstrongformworkkeepsitsshapewhenfilledwithwetconcrete

Alternative:

• Plywoodisgood.Itishasasmoothsurface,butitisnotthickenough.• Plywoodmustbesupportedbytimberstostrengthentheformwork• Therearenoalternativestowell-builtformwork• Themoretimeyouspendonbuildingtheformwork,thebettertheconcretewill

be



Formwork

Timber(wooden)supports

Plywoodsheet

Distanceshouldnot more than 80cm

Brackets

Acolumnformworksetuponsite

Why is it better ?

• Bracketstietheplywoodsheets(orboards)oftheformworktogether• Thedistancebetweenbracketsshouldbebetween50cmand80cm,closer

togethernearthebottom.• Sheetsofformworkarethickenough• Strongformworkwillkeepitsshapewhenfilledwithwetconcrete

Alternative:

• Therearenoalternativestowell-builtformwork• Themoretimeyouspendonbuildingtheformwork,thebettertheconcretewill

be



Formwork

Formworkforthecolumns

Bracesholdupformwork

Bracesholdupformworkforcolumns

Why is it better ?

• Strongformworkwillkeepitsshapewhenfilledwithwetconcrete• Bracketstiethesheets(orboards)oftheformworktogether• Formworkboardsarethickenough• Formworkforcolumnsisbracedfromtwosidestokeepitstraight

Alternative:

• Therearenoalternativestowell-builtformwork• Themoretimespentonbuildingformwork,thebettertheconcretewillbe



Formwork

Bracingfromtwodirections

Anchorsforwallconnections

Bracketsboltedtogether

Bracingfromtwodirectionsisessentialforformworkforcolumns

Why is it better ?

• Well-bracedformworkwillnotshiftortiltduringpouring• Formworkforcolumnsshallnotexceed5minheightbecauseconcreteshould

not be dropped from a great height• Heightbetweenhorizontalbeamsshallnotexceed3minordertomaintain

safetyduringearthquakes• Thereareholesandwallanchorsinstalledthroughtheformwork• Thetiebracketscanbeofdifferentshapebuttheyshouldtietheboardsofthe

formworktogether

Alternative:

• Wetconcreteshallnotbedroppedmorethan5m,otherwisetheaggregateswillseparate

• Thereisnoalternativetogoodworkmanship



Formwork

Additionalbracingon top

Bracing

Brackets

Anchorforbrickwalls

Horizontalbracingprovidesmorestabilitytothecolumnformwork

Why is it better ?

• Bracingprovidesmorestabilitytotheformwork,soitcannotshiftortiltwhenthewetconcreteisplaced

• Leaveholesintheformworkforthewallanchors

Alternative:

• Concreteshallnotbedroppedmorethan5m,otherwisetheaggregateswillseparate




Formwork

Maximumheightis5m

Bracingatright angles

Bracingatright angles to eachother

Formworkfromtwosidesisessentialforverticalcolumns

Why is it better ?

• Theformworkcannotmoveduringconcreteplacement• Theformworkforcolumnsshallnotexceed5minheight• Heightbetweenhorizontalbeamsshallnotexceed3mtomakesurethe

structureisearthquake-proof

Alternative:

• Wetconcreteshallnotbedroppedmorethan5m,otherwisetheaggregateswillseparate




Formwork

2directionbracesforcolumns

BracketsWoodenforms

Well-builtandstrongformworkforconcretebeamsandcolumns

Why is it better ?

• Strong,well-builtformworkisessentialforgoodqualityconcretestructures• Thethicknessofthesheetsofformworkisadequate–atleast2cmthick

Alternative:

• Thereisnoalternativetostrongformwork



Formwork

Supportsforbeamformwork

Solidsupportforformwork

Supportsforslabformwork

Why is it better ?

• Well-builtformworkisessentialforgoodqualityconcretestructures• Elevatedslabsorbeamsmustbesupportedat50cmspacingtoavoidsagging• DoNOTremovethebottomformworkandsupportsfor28days,sothatthe

concretewillreachitsdesignstrength

Alternative:

• Thereisnoalternativetostrongformwork



Formwork

Supports for beam forms

Roof beam

Formworkforroofbeamsmustbewellsupported

Why is it better ?

• Supportformsforbeamsat50cmspacinguntilconcretereachesitsstrength

Alternative:

• Thereisnoalternativeforstrongsupportsforformwork



Formwork

Roof beam

Beam supports shouldbeat50cmintervals

Wirecannotreplacesolidtiebrackets

Formworkforcolumn

Formworkforbeamsmustbewellsupported

Why is it better ?

• Supportformworkforbeamsat50cmspacinguntilconcretereachesitsstrength

• Usewoodentiebracketsinsteadofwire

Alternative:

• Thereisnoalternativeforgoodsupport



Formwork

Concreterafter

Beam support

Formworkforconcreteraftersmustbesupported

Why is it better ?

• Supportformworksforbeamsat50cmspacinguntilconcretereachesitsfulldesign strength

Alternative:

• Thereisnoalternativeforgoodsupports



Reinforcement

Theserebarsshould overlap 50cm

50cmoverlap

TopLayerØ12mm12mm

TieØ8mm

BottomLayerØ12mm

Toplayer–redBottomlayer-green

Theremustbeaconnectionbetweenboththerebarsofthebottomandthetoplayerofreinforcement


• Bendtherebarsasshownandfixthemtogetherwithwire• Lengthofoverlapmustbe40timesthediameter,oraminimumof50cm

Why ?

• Overlapisessentialtoextendthestrengthoftherebarsthroughoutthestructure

• Well-tiedandconnectedrebarsareabasicelementofreinforcedconcretestructures

• Fixingthereinforcementshouldbedonewithgreatcare



Reinforcement

Thisrebarshall overlap with the rebar crossingataright angle

50cmoverlap

Onlytoplayerismarked

50cmoverlap

Horizontalrebars

Theremustbeaconnectionbetweenboththeserebars(bottomandtoplayers)


• Bendtherebarsasshownindrawing• Fixingthereinforcementmustbedonewithgreatcare

Why ?




Reinforcement

End of rebar must have a hook

50cmoverlaptonextrebar

Thesearetheoutlines of the rebars

Onlytoplayermarked

TheremustbeNO“dead”endofrebars–theymustbeconnectedtotheadjacentrebars in the same plane


• Uselongerpiecesofrebars• Rebarmustneverendwithouta“U”hook• Bendtherebarsasshowninthepicture(anddrawings)• Fixingthereinforcementmustbedonewithgreatcare

Why ?




Reinforcement

Rebars for Column

Thereisnooverlap to other rebars

Rebars for foundation beams

Strings for setting out

Rebars for foundation beams

Rebarsmustbeconnected,i.e.tiedandoverlapped,toeachother


• Tierebarstogetherwiththin,flexiblewire• Eachrebarmustbetiedorconnectedtotheadjacentrebars

Why ?

• Onlywell-tiedrebarswillensurethestrengthoftheconcrete• Connectingtherebarsmustbedonewithgreatcare• Well-tiedandconnectedrebarsareabasicelementofreinforcedconcrete

structures



Reinforcement

Rebars must betiedtoeachother

ThereshallbeNOspacebetweenrebars


• Bendtherebarsinaccordancewithwhat’sshownonthedrawings• Rebarshavetooverlapbyaminimumof50cm• Fixingtherebarsmustbedonewithgreatcare

Why ?




Reinforcement



Design dimension of column

Rebarsmustbecenteredinconcretestructure


• Theconcretecoverofrebarsmustbeatleast1-2cm• Eachrebarhastobeconnectedtotheadjacentone(s)• Fixingtherebarsmustbedonewithgreatcare

Why ?

• Adequateconcretecoverenablestheconcretetoreachitsdesignstrength



Reinforcement

ThecrosssectionofthecolumnMUST NOT be less than the design

Rebars must be straightandvertical

BricksareNOT formwork

Rebarsmustbefixedinastraightverticallinefrombottomtotop


• Rebarsforcolumnsmustbeinaverticalstraightlinefromthefoundationuptothe roof beam

• Thedimensionsofthecrosssectionofanycolumnorbeammustnotbereduced

• Thedimensionsofacolumnshallnotbelessthan15x15cm• BricksareNOTformwork

Why ?

• Thecolumnisakeyelementofthehousestructure• Columnscarrytheloadoftheentireroof• Areducedcrosssectionincreasestheriskofcollapseduringanearthquake• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarepotentiallyaffectedby

earthquakes



Reinforcement

Column rebars must be straight andvertical

Overlapofrebars50cmminimum

Foundationbeam

Foundation

RebarsofcolumnsmustbeSTRAIGHT,notbent


• Rebarsforcolumnsmustbefixedtobeverticalandstraightfromthefoundationup to the roof beam

• Neverreducethedimensionsofthecrosssectionofanycolumnorbeam• Forcolumns,verticalrebarsmustbeaminimumdiameterof12mm,and

horizontalrebarsaminimumdiameterof8mm

Why ?

• Thecolumnisakeyelementofthehousestructure• Columnscarrytheloadoftheentireroof• Reducedcrosssectionsincreasetheriskofcollapseduringanearthquake• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarepotentiallyaffectedby

earthquakes



Reinforcement

Bentrebarsweakenthestabilityofthestructure

Column rebars must be straight andvertical

Rebars are not coveredinconcreteFoundationbeam

RebarsofcolumnsmustbeSTRAIGHT,notbent


• Rebarsforcolumnsmustbeverticalandstraightfromthefoundationuptotheroof beam

• Thesizeofthecrosssectionofanycolumnorbeammustnotbereduced• Thedimensionsofacolumnshallnotbelessthan15x15cm• Forcplumns,verticalrebarsmustbeaminimumdiameterof12mm,and

horizontalrebarsaminimumdiameterof8mm• Concretecoveroverrebarsmustbe2cm

Why ?

• Thecolumnisakeyelementofthehousestructure• Columnscarrytheloadoftheentireroof• Reducedcrosssectionsincreasetheriskofcollapseduringearthquakes• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarepotentiallyaffectedby

earthquakes



Reinforcement

Thesedistancesarenotequal

Ties

Thedistancebetweentherebartiesshouldbeconstant


• Fixrebartiesexactly15cmspacingfromeachother• Fixingthereinforcementmustbedonewithgreatcare

Why ?

• Rebarsareessentialforattainingthefullstrengthofareinforcedconcretestructure



Reinforcement

Twistedrebars

Rebarsmustbefixedstraightintheformwork


• Rebarsmustbeplacedinastraightline• Usespacers(blocks)underrebarstogettherightcoveroverthesteelrebars• Fixingthereinforcementmustbedonewithgreatcare

Why ?

• Twistedrebarscannotdevelopthefullstrengthofthereinforcedconcretestructure

• Rebarsareakeyelementofareinforcedconcretestructure



Reinforcement

Rebars without spacers/blocks

Bottom formworkforslab

Nospacers/blocksareusedtoholdtherebarsintherightposition


• Rebarsmustbesetonspacers/blockstogettherightconcretecover

Why ?

• Therearenoalternativestoproperlyfixedreinforcement• Themoretimeyouspendonfixingtherebarsandformwork,thebetterthe

concretewillbe



Reinforcement

Rebars sorted and stackedbysize

Rebarcagessortedandstackedonsupportstokeepthemclean

Productionofrebarcages

Assemblyandstorageofrebarsandcages

Why is it better ?

• Properlysortedandstackedrebarseasetheassemblyofrebarcagesaswellastheprogressofhouseconstruction

• Supportsunderthematerialskeeprebarsandcagesoffthegroundandclean

Alternative:

• Thereisneveranalternativetowell-organizedcleanstorage



Reinforcement

5cmBend

Ø12mm

8and12mmdiametersteelbarsarethemainelementsusedforreinforcement

Rebarstiedto-getherwith double wire

5cmBend

Ø8mm

Why is it better ?

• Checkthediameterofrebarstomakesuretheyarethecorrectsize• Thelengthofbendsateachendofthe8mmdiam.Tiesshallbe5cm,forthe12

mmdiamrebarsthelengthofthebendsshallbe8cm.• Properlyfixedandtiedrebarsoftherightdiameterareimportantforreaching

thedesignstrengthofthereinforcedconcreteelements• Allrebarsmustbetiedtoeachotheratpointswheretheycross

Alternative:

• Therearenoalternativestocorrectlysizedandfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe



Reinforcement

Foundationrebars–greenandblue

Allbluetiesareatthesamespacingof15cmoncenters Overlap50cm

Hook8cm Hook5cm

Column rebars-grey

Exampleofabeam&columnrebars(Coloursforillustrationonly)

Why is it better ?

• Correctlysizedandfixedrebarsareimportanttoreachingthedesignstrengthofreinforcedconcretestructures

• Allrebarsmustbeclean,freeofrustandtiedtoeachother

Alternative:

• Therearenoalternativestoproperlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe



Reinforcement

Alltiesareatequalspacing

Nospacerblocksareused-yet

Rebarsarefixedproperly

Why is it better ?

• Correctlysizedandfixedrebarsareimportantforreachingthestrengthofreinforcedconcretestructures

• Allrebarsmustbetiedtoeachother• Tieslocationsarevaried• Usespacerblocksbelowrebarstoensurecorrectconcretecover

Alternative:




Reinforcement

15cmspacingasper design

Ø12mm

Overlap50cm

Ø8mm

Rebarsareneatlyassembledbutspacerblocksarenotused-yet

Why is it better ?

• Thelengthofoverlapshallnotbelessthan50cm• Correctlysizedandfixedrebarsareimportantforreachingthedesignstrength

ofreinforcedconcretestructures• Allrebarsmustbetiedtoeachother

Alternative:

• Therearenoalternativestoproperlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe



Reinforcement

BricksareNOTformwork

Equalspacingbetween ties

Overlap50cmwith the rebars of foundation

Correctlyandneatlyinstalledrebars

Why is it better ?

• Correctlyfixedrebarsareimportantforreachingthestrengthofreinforcedconcretestructures

• Allrebarsmustbetiedtoeachother

Alternative:




Reinforcement

Adequateconcretecover

Column rebar wellcenteredon beams

Equalspacingbetween ties

Notetheconcretecover

Why is it better ?

• Concretecovermustbeatleast2cmtomakesuresteelrebarsarenotexposed• Allrebarsmustbetiedtoeachother

Alternative:

• Therearenoalternativestoadequateconcretecoveroverreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe



Reinforcement

ColumnrebarsØ12mm

TiesØ8mmspacedat15cmapart

90°AngleRebars bent into footing about 70to80cm

Fixingtheverticalcolumnrebarsinthefoundationtrench

Why is it better ?

• Alargefootingprovidesagoodbaseforthecolumnreinforcement• Bendthecolumnrebarsatan90°angleintothefooting• Rebarsarecleanandnotrusty

Alternative:

• Therearenoalternativestocorrectlyandneatlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe



Reinforcement

Correctlyassembled rebars

Rebarcageforafootingpadforanelevatedfloor

Why is it better ?

• Rebarsarecorrectlyandneatlyfixedinplace• Rebarsarebentatanexact90°angle

Alternative:




Reinforcement

Support from two sides at right angle

Column rebars

Support from two sides at right angle

90°angle

Trenchforfoundation

Supportsformtwosidestokeeptherebarsvertical

Why is it better ?

• Therebarsmustnotmoveduringconcreting• Rebarsmustbetrulyverticalsothatthecolumnwillbeperfectlystraight

Alternative:




Reinforcement

Supports at right angle

Column rebars

Supports at right angle

Supportsfromtwosidestokeeptherebarsvertical

Why is it better ?

• Therebarsmustnotmoveduringconcreting• Rebarsmustbetrulyverticalsothatthecolumnwillbeperfectlystraight

Alternative:

• Therearenoalternativestogoodreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe



Reinforcement

Rebarstoconnecttoreinforcementtoroof ring beams

Anchorsforbrickwallconnections

Steelanchorsarenecessarytotiethebrickwalltotheconcretecolumns

Why is it better ?

• Anchorstiethebrickwalltotheconcretecolumns• Columnsandwallsarebothelementsofthestructuralsystemandareessential

forthestrengthandstabilityofthehouse

Alternative:

• Therearenoalternativestocorrectlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe



Reinforcement

Anchorsforwallconnections

Rebars of lintel ring beam

Rebarsforconnectingto lintel ring beam

Rebars for connectingtoroof ring beams

Rebarconnectionstobeamsandwall

Why is it better ?

• Allstaticelementshavetobeconnectedtothestaticsystemofthebuilding• Allrebarshavetobeconnectedtoeachother

Alternative:




Beams & Columns

Lintels missing

Bricksusedasformwork

Columns were castin3sections

Solidframeworkisessential


• Firstpourtheconcretecolumnsuptotheroofbeam(beforebuildingthewalls)• Checksteelreinforcement• Usecontinuousformworkfortheentirecolumn• Buildthebrickwallsafterformworkhasbeenremoved

Why ?

• Thestrengthofaconcretecolumnincreaseswiththesizeofitscrosssection.• Acolumnthatistoolongrelativetoitscrosssectioncanbuckleunderheavy

loads.



Beams & Columns

Max.load bearingcrosssectionof columnasactuallybuilt

Required designcross sectionofthe

column

Fulldesigncrosssection

of the column

Columnsmusthavethedesigncrosssectionalongtheirentirelength


• Useplywoodformworkinsteadofusingthebricksasformwork• Thedimensionsofanycolumnshallnotbelessthan15x15cm• BrickworkisNOTformwork!

WHY ?

• Thecolumnisthekeybearingelementofthehousestructure• Columnshelpholdupthewallsandcarrytheloadoftheentireroof• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofcolumnsareeasilyaffectedbyearthquakes



Beams & Columns

Rebars must be vertical

ACTUALcross sectionforcarryingload

Designcross sectionreq’d

Columnsmusthavethedesigncrosssection


• Thedimensionsofaconcretecolumnshallnotbelessthan15x15cm• Useplywoodformworkinsteadofusingthebricksasformwork• BrickworkisNOTformwork!• Rebarsmustbefixedinaverticalposition

WHY ?

• Thecolumnisthekeybearingelementofthestructureofahouse• Columnshelpholdupthewallsandcarrytheentireloadoftheroof• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarelikelyaffectedby

earthquakes



Beams & Columns

Uppersection ofthecolumn

Actualloadbearingcross section

Lowersectionofthecolumn

Design load bearing crosssection

Thefulldesigncrosssectionofacolumnisessentialforthestrengthandstabilityoftheentirestructure


• Thedimensionsofacolumnshallnotbelessthan15x15cm• Usecontinuousformworkfortheentirecolumn• Useplywoodformworkinsteadofusingthebricksasformwork• BrickworkisNOTformwork!

WHY ?

• Thecolumnisthekeybearingelementofthestructureofahouse• Columnshelpholdupthewallsandcarrytheentireloadoftheroof• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarelikelyaffectedby

earthquakes



Beams & Columns

Reinforcingbarsarenotcoveredbyconcrete

Thiscolumncannot carryanyloadatall

Concreteisnotwellcompactedandthecolumnsarecompletelyoutofshape–theactualcrosssectioncannotcarryanyloads


• Rebarsmustembeddedinwell-compactedconcrete• Coveroverreinforcementmustbeaminimumof2cm

WHY ?

• Everybeamorcolumnisaload-bearingelementinthesystemofahouseandhastobecarriedoutverycarefully

• Concretewillneverreachfullstrengthwhenitisnotwellcompacted• Reinforcementandtheconcretearounditconstitutethestrengthofthebeam/

column



Beams & Columns

Noconcrete inthecolumn

No Cover on rebars

No Cover on rebars

Thesecolumnscannevercarryanyloads!


• Makesurethattheconcreteiswell-compacted• Usesolidformworkonly–bricksarenotformwork• Watchoutthatthereinforcementhasaminimumcoverof2cm

WHY ? • Onlythejointactionofreinforcementandconcretewillmakestrongcolumns

andbeamstogetarigidandstableload-bearingsystem.• Earthquake-proofsystemneedsarigidframework



Beams & Columns

Honeycombs

Honeycombsshowinglesscompactionduringpouring


• Compacttheconcretewellduringtheentirepouring

WHY ?

• Onlywell-compactedconcretehasstructuralstrength• Theconcreteframeispotentiallyaffectedbyearthquakes,thereforefull

attentionhastobegiventotheconcreteworks



Beams & Columns

Poormixingof aggregates

Honeycombs

No bonding betweenfoundation and beam

Rebars twisted

Not enoughcompaction

Honeycombsweakenthestrengthofconcrete


• Compactconcreteoftenandwithcareduringpouring• Makesurethatconcreteaggregatesdonotgetseparated

WHY ?

• Onlywell-compactedconcreteachievesthenecessarystrength• Theconcreteframeofcolumnsandbeamsispotentiallyaffectedby

earthquakes,thereforeconcreteworksmustbedonewithgreatcare



Beams & Columns

Continuation ofcolumn

King postof truss is inclined

Should be in the

same spot

Kingpostshouldbeplacedstraightontopofthecolumn


• Movethekingposttothetopofthecolumn

WHY ? • Theverticalloadonthekingpostshouldbetransferreddirectlytothecolumnsand

foundation• Theconcreteframeispotentiallyaffectedbyearthquakesthereforetheconcrete

worksmustbedonewithgreatcare



Beams & Columns

Foundation beams are well-builtAsolidstone

foundation

Thiswell-shapedfoundationgridisasolidbaseforthehousestructure

Why is it better ?

• Asolidfoundationisthebestbaseforahouse • Buildastronggridoffoundationbeamstogetastrongstructure

Alternative:

• Thereisnoalternativeforagoodfoundation

A solid stone foundation



Beams & Columns

Brickwork foundation

Foundation beamsFill must be

compacted

Foundationbeamswerecastwithgoodformwork

Stone foundation

Foundation beams

Why is it better ?

• Strongformworkhelpstoachievethefullstrengthoftheconcretesothatthestructurecanresistearthquakes

Alternative:

• Thereisnoalternativeiffullconcretestrengthshouldbeattained



Beams & Columns

Beams of the foundation grid

Column and

beams are well

built

Base for the floor slab

Thehousestructuremustbebuiltonasolidfoundationgrid

Why is it better ?

• Asolidfoundationisthebaseofastronghousestructure • Asolidgridoffoundationbeamswillmakeastrongstructure

Alternative:

• Thereisnoalternativeforagoodfoundation



Beams & Columns

Roof ring beamColumns are well

built

Agoodconnection between roof ring beamsandcolumn

is important

Lintel beam

Theskeleton(framework)ofthestructureshouldlooklikethis

Why is it better ?

• Asolidskeleton(framework)isessentialforanearthquake-proofbuilding

Alternative:

• Thereisnoalternativeforbuildingasolidstructure



Beams & Columns

Inner edge of column

Outer edge of column

Column built with formwork

Why is it better ?

• Askeleton(framework)isessentialforanearthquake-proofbuilding

Alternative:

• Thereisnoalternativeforbuildinggoodqualitystructure



Beams & Columns

Wallanchors

Foundationbeamsandcolumnswithwallanchorsbuiltusinggoodformwork

Why is it better ?

• Goodformworkisessentialforanearthquake-proofbuilding • Afterremovaloftheformwork,thebricklayingcanstart

Alternative:

• Thereisnoalternativeforgettinggoodqualityconcrete



Beams & Columns

Connectingrebars

Well-builtcolumns

Lintel beam over windows

Max.3mto found.beam

Roof beam will be placedhere

Thisdistanceshallnotexceed50cmwithouta

lintel beam

Alintelbeammustbeusedwhenthedistancebetweenbottomoftheroofbeamandtopframeofanywindowsordoorsismorethan50cm

Why is it better ?

• Theareainsideanyframeofcolumnsandbeamsshallnotexceed12squaremeters

• Solidformworkisessentialforattainingthegoodqualityconcretethatisneededforearthquake-proofbuildings

Alternative:

• Thereisnoalternativeforbuildingagoodqualityconcretestructure



Slab

Wellbuiltcolumnswithwallanchors

Elevated slab

Postfoundation

Theelevatedslabissupportedbyaconcretepost(orpile)foundation

Why is it better ?

• Inareaswherefloodingispossible,itisrecommendedtobuildthehousesonanelevated slab

• Theconcretepost(pile)foundationmustbebuiltwithgreatcare,becausethepilescarrytheentireloadofthehouse

Alternative:

• Thereisnoalternativetodoinggoodqualityconcretework

WallsChapter 04

83Chapter 04 Walls BAD


Materials

Untidystorageofbricks


• Stackbricksneatly–thereislesschanceofbreakage

WHY ?

• Brokenbricksmakeweakerbrickwalls

84 Chapter 04 WallsGOOD


Materials

Brickstorage

Concretebricksofstandard dimensions

Left:Wellstackedclaybricksofstandarddimensions,i.e.20x10x5cm

Why is it better ?

• Well-storedbrickswillnotgetbrokenandbricklayingwillbeeasier

Alternative:

• Wallsmadeofhollowconcreteblocks



Construction

Brokenbricks

Defective,brokenandpoorqualitybricksweakenthewall


• Bricksofgoodqualitymakesforstrongerwalls • Handlebrickswithcareandstackthemintidypilesonthestoragearea

WHY ?

• Bricksaremadeoffiredclayandbreakeasily • Bricksgettheirstrengthwhenlaidincementmortarinmasonrywalls

86 Chapter 04 WallsBAD


Construction

Thejointsareaswide asthebricks!

Thejointsaretoolarge


• Makevertical&horizontaljointsonly1.0to1.5cmwide • Thebricksmustbelaidperfectlylevel

WHY ?

• Widejointsarenotgoodforthestabilityofthewall



Construction

Horizontal Line

Brickcoursesarenot level

Brickcoursesarenot level

Bricksnotlaidlevel,i.e.notinahorizontalline


• Thejointsmustbebetween1.0and1,5cmmaximum • Thebrickshavetobelaidlevel,i.e.inahorizontalline

WHY ?

• Unevenjointsandbrickworknotlaidlevelmayaffectthestabilityofthewall



Construction

Brickjointsarenot

Bricksmustlaid leveland with

Edge of brickwork

Bricksmustlaid leveland with

NOanchorswere used

Design width ofcolumn

Thiswallshowsmanydefects


• Thiswallmaynotwithstandanearthquake • Followthesuggestionsinthisbookforbuildingbrickwalls • Firstcasttheconcretecolumnsandthenstartwiththebricklaying • Bricksmustbelaidlevelandplumb,andthejointsmustbeoffsetbyhalfabrick

lengthIeachlayer • Thesteelanchorsfromthecolumnsmustbeembeddedinthebrickwall

WHY ?

• UsingGOODconstructionpracticeasshowninthisbookwillresultingoodqualityhouse



Construction

ToppartofwallisOK

Jointsbetweenbricksare too wide

Bricksmustbelaidexactlylevel


• Setbricksexactlylevel,i.e.inahorizontalline • Thejointsmustbethesamewidth,i.e.1.0to1,5cmmaximum

WHY ?

• Awellbuilt,solidwallcontributestothestabilityofthehouse • Itiseasiertoputplasteronasmoothbrickwall



Construction

Unevensurface

Bricksusedasalternative tostonesorrocks

Evensurface

Bricksmustbelaidexactlyaligned(ontopofeachother)togetasmoothwallsurface


• Laybrickswithaplumblinetogetaperfectlyverticalline

WHY ?

• Awellbuiltbrickwallcontributestothestabilityofthehouse • Itismucheasiertoputplasteronasmoothwallsurface



Construction

Beam is sagging

Design width of columns

Edge of wall

Bricksarenotlevel

Wallshouldbebuiltaftercolumnshavebeenbuilt


• Buildthebeamfirst(withgoodsupports),thenbuildthecolumns,andlastthebrickwall

WHY ?

• Buildingintherightsequenceisimportantforagoodqualityhouse



Construction

Brickscandistribute load

better when laidlikethis

Load of the wall above

BricksareOKon this side

Center line

Thisishowabricklintelcouldbebuilt


• Laythebricksforthelintelasshownonthepictureabove

WHY ?

• Alintelmustcarryanddistributetheloadofthewallabovetheopeningtotheadjacentwallsandcolumns(whichcarrytheloadtothefootings)

93Chapter 04 Walls GOOD


Construction

Jointsshouldbe 1.0to1.5cm

Connectionto column

Claybrickwall

Why is it better ?

• Thejointsmustnotexceedthedimensionsshown • Thebricksofthenextlayeruparelaidcenteredonthejointofthelowerlayer • Thejointtothecolumnisexecutedneatly

Alternative:

• Wallmadeofhollowconcreteblocks



Construction

Theindicatedareaisto12m2 max.

Max.heightbetweenbeams 3m

Areabetweencolumnsandbeamsshallnotexceed12m2

Why is it better ?

• Areaslargerthan12m2willnotresistevenmoderateearthquakes • Forstabilityreasonsitisveryimportantthattheanchorsfromthecolumnsare

embeddedinthebrickwork

Alternative:

• Thereisnoalternativeforbuildingstablewalls



Construction

Bricksstackedona board for ease of work

60 cm

Column with

Anchorsfor walls

Mortarjoints

Bricklayingtakesplaceafterbuildingthecolumns

Why is it better ?

• Afterremovaloftheformwork(forbeams&columns)bricklayingcanstart • Forreasonsofstabilityitisimportantthattheanchorsareembeddedinthe

brickwork • Upto60cmabovefoundationbeamthejointsofthebrickworkhavetobedone

withwaterresistantmortar(1,5unitsofcementinsteadof1unit)

Alternative:

• Thereisnoalternativetogoodconstructionpractice



Construction

Wallanchors

Foundationbeams

Columns

Anchorgetsembedded in brickwork

Connectionofcolumntobrickwall

Why is it better ?

• Theconnectionmustbedonewithcare • Tomaketheconnectioneffective,itisimportantthatthesteelanchorsare

embeddedinthebrickwork

Alternative:

• Thereisnoalternativetogoodwallanchors



Doors & Windows

Supports

Foundationbeamnotyetpoured

Door frames

Door&windowframesmustnotbeinstalledbeforetheconcreteworkhasbeenfinished


• Buildcolumnsandbeamsbeforestartingbrickwork

WHY ?

• Itispreferabletofinishallconcreteworksfirstandthenstartwithwallconstructionandthendothedoorandwindowinstallation.



Doors & Windows

Lintelbricksshall be laid in two directions

Window frames

Edge of wall before window installation

Jointshouldbedonewithcare

Windowframemustbeinstalledbeforebuidingthewall


• Installthewindowanddoorframestogetherwithbuildingthewall • Bricksforlintelshouldbesetintwodirections(similartoanarch) • Keepasmallspacebetweenwallandframesandfillitwithmasonry

WHY ?

• Agooddesignminimizesproblemsonsite



Doors & Windows

Door frames

Windowframes

Framesreadyforinstallation

Why is it better ?

• Framesarestackedforstorage(theyshouldbeonsupports)

Alternative:

• Goodpreparationandorganizationeasestheprogressofwork



Doors & Windows

Temporary supports

Windowframes

Windowframesreadyforinstallation

Why is it better ?

• Temporarysupportsholdandfixtheframesinanuprightpositionduringconstruction

Alternative:

• Goodpreparationeasestheprogressofwork



Doors & Windows

Supports

Spacer

Spacebelow frame to be filled after wall is finished

Cornerbrace keepsframerectangular

Spacersbelowtheframeholditinalevelposition

Why is it better ?

• Temporarysupportskeeptheframesinaverticalpositionduringconstructionwork

• Spacer(blocks)holdtheframeinalevelpositionduringtheconstructionofthewall

Alternative:

• Thereisnoalternativetogoodqualityworkmanship



Doors & Windows

Supportsoutside building

Spacer

Corner brace keeps framerectangular

Louvres above window

NO lintelbeam

Supportscanalsobeinstalledoutsidethestructure

Why is it better ?

• Supportsholdtheframesinaverticalpositionduringtheconstructionofthewalls

• Spacerskeeptheframeinalevelpositionduringwallerection

Alternative:

• Therearenone–goodtemporarysupportsareessential



Doors & Windows

Supports outside the

building

Supports fixedtothe ground

Rigid triangle

Castcolumns before building the walls

Therigidtrianglesformedwiththesupportskeeptheframesinafixedposition

Why is it better ?

• Temporarysupportsandframesformarigidtriangle • Supportskeeptheframesinaverticalpositionduringconstructionwork

Alternative:

• Goodworkpreparationeasetheworkatall



Doors & Windows

Lintel

Lintel included in roof beam

Alintelhastocarrytheloadofthewallabove

Why is it better ?

• Bricksinlintelareinclinedinbothdirections • Roofbeamisextendeddowntotopedgeofwindowframe

Alternative:

• Lintelscanbebuiltofbricksorofconcrete • Useconcretelintelbeamwhenverticaldistancetoroofbeamexceeds50cm



Plaster

60cmofwater-resistant plaster

Plastermakesasmoothwallsurface

Why is it better ?

• Topreventmoisturefrompenetratingthewallsthelower60cmofwallsshouldbeplasteredwithawater-resistantplaster(1,5unitsinsteadof1,0unit)

Alternative:

• Tarpaperorplasticsheetscanbelaidontopoffoundationbeamtopreventmoisturefrompenetratingthebricks



Plaster

60cmofwater-resistant plaster

Alintelhastocarrytheloadofthewallabove

Why is it better ?

• Topreventmoisturefrompenetratingthewallsthelower60cmofwallsshouldbeplasteredwithawater-resistantplaster

• Thefinalappearanceofthehousecanbesomewhatshapedwithplastertogiveitanindividuallook

• Before painting the plaster have to be dried out

Alternative:

• Thealternativeistoleavetheexteriorfinishuptotheowner

RoofChapter 05



Roofing Materials

Notwellfixedto the purlins

Sheetshavetobefixedreallywell


• Onlyproperlyinstalledandsealedroofingmaterialsguaranteealeak-proofroof • Improperlyfastenedorlooseroofingmaterialsposeaseriousriskduringstorms

WHY ?




Roofing Materials

NOrubbersealused

Nail on top of roof ridges

Rubbersealisneededforaleak-proofroofNotethelargeheadoftheroofingnail


• Userubbersealsaroundtheroofingnailsorscrews • Putnailsonthetopofridges

WHY ?

• Thereisnoalternativeofgoodworkmanship

109GOODChapter 05 Roof


Roofing Materials

Overlapof sheets

PurlinCorrugated steel sheets

Corrugatedsteelsheetstogetfixedonpurlins

Why is it better ?

• Start at the bottom end to mount the sheets • Asufficientoverlapensuresnowaterleaksintothehouse

Alternative:

• Otherdesignofcorrugatedroofsheets • Fibrecementsheets–maybecoloured • Rooftiles,butmuchmoreexpensive

110 GOOD Chapter 05 Roof


Roofing Materials

Sheetsandcaps screwedtothe

purlins

Ridgecapcoversthetop edge of the

sheets

Overlapof ridgecaps

Screwprotected withacap

Exampleoffibrecementroofingsheets

Why is it better ?

• Overlapisessentialforalltypesofroofingsheets • Allnailsorscrewsmustbeofstainlesssteel/galvanizedandhaverubberseals • Allnailsorscrewsshouldbecoveredwithaplasticcap

Alternative:

• Rooftiles,buttheyaremuchheavierandmoreexpensive • Galvanizedsteelsheetsarecurrentlythecheapestroofingmaterial



Roofing Materials

Nailed to purlin

Rubber sealunderplasticcovercap

Usenailswithaplasticcap

Why is it better ?

• Theremustbearubbersealbetweenroofingsheetandroofingnails(orscrews) • Galvanizedorstainlesssteelmaterialsshouldbeusedbecausetheydonotrust

Alternative:

• Roofingtiles,buttheyaremuchheavierandmoreexpensive • Fibrecementsheets • Galvanizedsteelsheetsarecurrentlythecheapestroofingmaterial

112 Chapter 05 RoofBAD


Aluminum Construction

Rafter

Tiebeam

Purlin

No truss connectiontothe ring roof

beam

Trussmustbefixedtoroofringbeam

Why is it better ?

• Rigidandstrongconnectionsareessentialforastableroofframe

Alternative:

• ThetraditionallyusedmaterialisstillwoodanditisagoodalternativeAluminumConstruction




Purlinextensions

Ridge BoardRafter

Woodenrafterextension

Aluminumrooftrusses

Why is it better ?

• Roof truss frames of aluminum are lightweight and do not rust • Aluminumneedsnopainting • Thismetalisstrong,butalsoexpensive

Alternative:

• Thetraditionalmaterialisstillwood,butitmustbepaintedregularly.




Rafter

PurlinTiebeam

Solidconnection to roof ring

beam

Aluminumtrussconnectiontoroofringbeam

Why is it better ?

• Allrooftrussesmustbetiedtotheroofringbeam

Alternative:

• Woodisstillagoodalternative




Rafter extension

Frontboard

Purlin

Aluminumtrussdetailwithwoodenextensionforfixingwoodenfrontboard

Why is it better ?

• Itiseasiertofixthefrontboardtothewoodenrafterextensions

Alternative:

• Woodenrooftrussesarestillagoodalternative.



Wood Construction

Thiswireis not enoughtofix

the rafter to the wall

Theraftermustbe supported on entire

length of the wall

Wellsupportedraftersimprovethestabilityoftheroof


• Buildthewallallthewayuptotherafter,sothesupportisoveritsentirelength • Useflatsteel(plates)andboltstofixtheraftertothewall

WHY ?

• Thebettertheraftersaresupported,thestrongertheroofconstructionwillbe • Raftersneedtobesupportedwhentheyarenottiedtogetherbythetiebeam

117Chapter 05 Roof BAD


Wood Construction

Trussnotfixedtotheroof ring beam

Rafter Purlin

TieBeam

WallPlate

Theentirerooftrussmustbefixedtotheroofringbeam


• Useflatsteel(plates)andboltstotiethetrusstotheroofringbeam

WHY ?

• Thebettertheconnectionofthetrusstothewall,thestrongertheroofconstructionwillbe.



Wood Construction

y

Rafter

s

Tiebeamextensionandkingpostnailed together onl

Trussnotfixedtoroof ring beam

Cross Beam

Makesurethattherooftrussisproperlyconnected


• Boltsarebetterthanjustnailsforalltrussconnections • Useflatsteel(plates)andboltstotiethetrusstotheroofringbeam

WHY ?

• Thebettertheconnectionsofthetrusstothewall,thestrongertheroofconstructionwillbe.

119Chapter 05 Roof BAD


Wood Construction

Cross beams

Thisisno alternative to angle struts

TiebeamAnglestrut

Arooftrusswillreachitsfullstrengthwhenallmembersaretiedtogether


• Useproperanglestrutsinsteadofunapprovedconnectionstothewall

WHY ?

• Arooftrussisastructuralsystemandcanonlyfunctionassuchwhenallmembers are tied together

• Thebettertheconnectionsofthetruss,thestrongertheroofconstructionwillbe.



Wood Construction

Purlin

Anglestrut

Secondary post

Theconnection should bethe other

wayround

RafterExtension

ConnecttheextensionONTOPoftherafter


• Theextensionmustbemountedon top oftherafterandmustbeconnectedwithatleast2boltsthroughbothmembers

WHY ?

• Bothmembersmustfunctionlikeonestructuretocarrytheloadoftheroof • Thebettertheconnectionsofthetruss,thestrongertheroofconstructionwill

be.



Wood Construction

Assembled stackedtrusses

Stackedtimber Productionofroof

trusses

Productionofrooftrusses

Why is it better ?

• Timbersortedandstackedbysizeeasetheproductionofrooftrussesaswellastheprogressofhouseconstruction

Alternative:

• Thereisneveranalternativeforagoodorganisationonaconstructionsite.



Wood Construction

Crossbeams

Anglestrut

Bottom tie beam

Purlin

t

Uppertiebeam

Bolts for good connectionsKingpos

Themainpartsofarooftrussframe

Why is it better ?

• Well-builtrooftrusseswillresistwindstormsandearthquakes

Alternative:

• Thereisnoalternativeforgoodworkmanship



Wood Construction

Connectionofkingpostandtiebeamwithboltsonly

Connectraftersectionswithboltsonly

PurlinKingPost

Connecttiebeamsectionswith bolts

Howconnectionsofwoodentrussmembersshouldbemade

Why is it better ?

• Theconnectionsofthewoodentrussmembersmakeitarigidframe • Boltsconnectionsaremuchbetterandstrongerthannails • Boltsarescrewedthroughbothwoodensectionsandtiethemtogether

Alternative:

• None



Wood Construction

Kingpostconnections

Truss

Crossbeamsfixedtothekingspostsmakethestructurestable

Why is it better ?

• Thetrussesmustbetiedtogetherwithtwocrossbeamstoconnectthetrussestoeachother

• Thecrossbeamsstabilizethetrussesvertically • Boltedconnectionsarebetterthannails

Alternative: • None



Wood Construction

s Secondcrossbeamnotyetinstalled

Trusse

Rigidconnectionbetweentrussand roof ring beam

Thepictureshowswherethetrusseshavetobeconnected

Why is it better ?

• Tightconnectionsareimportanttomakethetrussesstrong

Alternative:




Wood Construction

Boltsoneachsideoftruss areembeddedinconcreteroof beam

Rafter

Flatsteelplate connectsthebolts

Tiebeam

Concrete roof beam

Thetrussmustbemountedon,andfixedto,theroofringbeam

Why is it better ?

• Tightconnectionsbetweentrussandconcreteroofringbeamareessentialforastrongconstruction

• Boltsfastentheflatsteelplatetightlytothebeam

Alternative:

• Bentrebarsofthecolumncanalsobeusedtotiethetrussestoroofbeam,buttheymustbefixedtothetruss



Wood Construction

Bent rebars

Holefortheboltwhichisthreadedthrough the tie beam and rafter

Rebarsextendingfromthe columntotiethetrusstightlyto the ring roof beam

Thisflatsteelplateisonepartof trussanchoranditissetintheconcreteoftheringbeam

Differenttypesoftrussanchors

Why is it better ?

• Tightconnectionsbetweentrussandconcreteroofringbeamareessentialforarigid truss frame

• Boltsfixtheflatsteeltighttothetruss

Alternative:

• Thereisnoalternativetostrongconnectionsbetweenthetrussandtheroofring beam



Wood Construction

Rebarssetinconcrete, bent&fixedtothepurlin

Concreterafters

Purlinsmountedonconcreterafters

Why is it better ?

• Tightconnectionsareimportanttokeepthepurlinsinplacefortheroofing • Spacingofpurlinsdependsonroofingmaterials

Alternative:




Wood Construction

Purlinsupportmounted on a wooden rafter

Goodinstallationfor rafterextension

Goodexamplesofrooftrussframeconstruction

Why is it better ?

• Tightconnectionsareimportanttoholdthepurlinsinplacefortheroofing • Theconnectionofrafterextensionsmustbedonewithcare–atleast2bolts

mustbeusedthroughbothwoodensections

Alternative:


FloorChapter 06

131Chapter 06 Floor GOOD


Construction

Sand10-15cm

Gravel

Backfillvaries,wellcompacted

FinishedFloorConcrete5-8cm

Sand compacted

Rocksembeddedinwater resistant

concrete

Sand/Gravel

Verticalcrosssectionoffloorconstruction

Why is it better ?

• Thisfloordoesnotdrawinmoisture • Watercanseepawayintothegroundanddoesnotaffectthebuildingorits

foundations

Alternative:

• Themoretimespentonplacingthedifferentlayer,thebetterthequalityofthehousewillbe.

132 Chapter 06 FloorGOOD


Construction

Backfill(soil) readyfor

compaction

Compactedbackfillisthebaseforthefloorconstruction

Why is it better ?

• Althoughcompactionhasnetbeendoneinthislayers,butwell-compactedbackfillpreventslatersettlingoftheconcretefloorslab

Alternative:

• Themoretimespentonplacingthedifferentfloorlayer,thebettergetsthequalityofthehousewillbe

133Chapter 06 Floor GOOD


Construction

Wellcompactedandlevelledbackfill

Backfillisthebaseforthefloorconstructionandmustbewellcompacted

Why is it better ?

• Compactiontobedoneforeachlayerofbackfill • Layersofbackfillshallnotexceed20cmindepth • Whenthebackfilliswellcompactedtheconcretefloorslabcannotsettleor

crack

Alternative:

• Themoretimespentoncompacting,thesmallertherisksoffloorsettlementsorcracking

134 Chapter 06 FloorGOOD


Construction

Well executed floor slab construction

Floorslabisthebaseofthefinishedfloor

Why is it better ?

• Thesurfaceissmoothandwelllevelled • Thisisgoodbaseforfloortiles,linoleumorjustpaintingthesurface

Alternative:


ServicesChapter 07

135Chapter 07 Services BAD


Electricity

Cablemayrubatthe edgeofcolumn

Wiresfixedonplasteronly

Avoidcablescomingintocontactwithsteel

elements

Cablesshouldbeinstalledinplastic(PVC)ducts


• Forincreasedsafety,electricalwiresshouldbeinstalledinPVCducts • Installtheductsinastraightlineundertheplaster–itmakesiteasiertofindthem

later on • Preferably,electricalwiresshouldbeinstalledoutofreach,i.e.higherthan2,5m • Inmasonrywalls,theductsshouldbeinstalledinthewalloratleastinthe

plaster,inwoodenstructurestheductsareinstalledonthesurface

WHY ?

• Asafeelectricalinstallationshouldpreventsystemfailuresandalsobenothreattohumanhealthandsafety

136 Chapter 07 ServicesBAD


Electricity

Avoidductscrossingsthrough beams

Betterlocationfordistribution line

Cablesclampsaregood

Wireductshavetobefixedtothewall


• Minimizepenetratingbeamswithductstoavoidweakeningofthebeam • Electricalwiresandductsshouldbeoutofhumanreach,higherthan2,5m

WHY ?

• Asafeelectricalinstallationpreventssystemfailuresandshouldmeethumanhealthandsafetyrequirements



Electricity

ExtendtheductbelowtheceilingInstallahookto

taketheweightof thefixture

Cablemayrubon sharp edge of

ceiling

Installationofelectricalfixturebelowtheceiling


• Electricalcablesshallnotrubattheedgeofthesuspendedceiling • InstallwiresinaPVCductthatextendsbelowthesuspendingceiling

WHY ?

• AfaultyelectricalInstallationcouldcausedamagetothehouse • Apoorinstallationisalsoarisktohumanhealthandsafety

138 GOOD Chapter 07 Services


Electricity

Switchandplug installed inplaster wall

Cable installed in duct&covered byplaster

Installation ductcovered with plaster

Beforeandafterelectricalinstallation

Why is it better ?

• Thewiresareinstalledinaductandlaidintheplaster • Thesafetyriskisreducedtoaminimum

Alternative:

• There’sneveranalternativetoasafeelectricalinstallation



Water & Sanitation

Pipe outlets

Never penetrate a beam with a larger pipe


• Neverpenetratebeamswithanylargerpipetoavoidweakeningthebeam • Set water and sanitation pipes below natural ground level • Crossfoundationabout60cmbelowgroundlevel

WHY ?

• DoNOTweakenthestrengthofaconcretebeam–itisanimportantelementoftheearthquake-proofstructure

• Pipeslaidbelowgroundarebetterprotectedagainstdamageordestruction

140 GOOD Chapter 07 Services


Sanitation

2nd Chamber for aerobictreatment

1st Chamber for settling of sludge

Inletfromhouse

Outlettosoakaway

or drain

Accessmanhole

Septictankfortreatinghumanwaste

Why is it better ?

• Thetwochamberspartiallytreat(clean)thewastewater • Chamberwithsettledsludgemustbepumpedoutregularly(whenfull) • Accessmanholeisessentialforinspectionandpumpingout • Vent pipe is needed • Removeformworkoftankcover

Alternative:

• Directconnectiontoasewersystem–ifavailable

the good and the bad infrastructure books (edition 4) - housing construction

Documents

good examples

good quality housing

iithe good

good experience

construction costs

serious efforts

technical training

major reconstruction