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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 : oherawati@worldbank.org
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
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
12 Important Rules
THE GOOD & THE BAD INFRASTRUCTURE
Setting OutChapter 01
1Chapter 01 Setting Out BAD
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
Setting out
Dispose of plants andwastefirst
Rottenplantsandwastearenotagoodbaseforfloorconstruction
How can I do it better ?
• Thesiteshouldbecleanedupbeforestartingtheexcavation
Why ?
• Organicmaterialwillrot,andthegroundwillsettle• Wastemightbecontaminated
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
5Chapter 01 Setting Out GOOD
Setting out
Intersectingstringsshowthecenterofcolumns
…butstringscanalsomarkcenterlinesoffoundations
Stringscanmarkthe width of the foundation…
Theaboveexamplesshowtheimportanceofstringsinmarkingallimportantpointsandlinesofthestructure
FoundationChapter 02
7Chapter 02 Foundation BAD
THE GOOD & THE BAD INFRASTRUCTURE
Excavation
No boards for strings
Roots of plants not disposed of
Trenchistoo shallow
Bottom of trench has to be levelled
How can I do it better ?
• Startwithit-Settingoutthetrenchalignmentandtrenchbottomandtopwithboardsoneachsideofthesite–startwithit
• Beforestartingtheexcavationthesiteshouldbefreefromallorganicmaterialand waste
• Foragoodfoundationaminimum70cmdeeptrenchisrequired
Why ?
• Organicmaterialwillrotandcausethegroundtosettle• Adeeptrenchfoundationmakesasolidbaseforthehouse
8 GOOD Chapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Foundationtrenchistoo shallow
Notenoughconcretebetweenrocks
Bottomrocklayernot embedded
Rock layer of foundation is not embedded in concrete
How can I do it better ?
• Deepenthetrenchtogetabetter,moresolidbaseforthefoundation• Therockshavetobeembeddedinconcrete• Foragoodfoundationaminimumof70cmdeeptrenchisrequired
Why ?
• Adeepfoundationtrenchmakesasolidbaseforahouse
11Chapter 02 Foundation BAD
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Foundationtrench
Bottomrocklayer–should not be in a straight line
Bedforrocks
Strings from setting out
Bottomrocklayerintrench
How can I do it better ?
• Rocksaresettoomuchinastraightline–theyshouldbeplacedrandomly
Why ?
• Thereisneveranalternativetosolidfoundationmaterial
12 Chapter 02 FoundationBAD
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Notenoughconcretebetweenrocks
Firstrocklayernotembedded
Foundationtrenchtoo shallow
Rocklayeroffoundationisnotembeddedinconcrete
How can I do it better ?
• Deepenthetrenchtogetasolidbaseforthefoundation• Therockshavetobewell-embeddedinconcrete• Forasolidfoundationaminimumof70cmdeeptrenchisrequired
Why ?
• Adeepfoundationtrenchmakesasolidbase
13Chapter 02 Foundation BAD
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Crackcausedbysettlement of the foundation
Movement of foundation
Acrackistheconsequenceofpoorlycompactedsubsoilorapoorfundationgenerally
How can I do it better ?
• Theexcavationofthetrenchbottomforthefoundationandtheconstructionofthefoundationitselfhavetobecarriedoutwithgreatcare.
• Rocksinthefoundationhavetobewell-embeddedinconcrete
Why ?
• Adeepfoundationtrenchmakesasolidbaseandreducesthechanceofgroundsettlements.
14 GOOD Chapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Movement of foundation
Rocksforfoundation
Why is it better ?
• Rockshavetointerlockeachother• Rocksofdifferentsizefilltheremainingspacesbetweenbigrocks• Rockscarrytheloadofthehouse
Alternative:
• There’sneveranalternativetosolidfoundationmaterial
15GOODChapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
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
16 GOOD Chapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Foundations
Spaceleftforsetting out the reinforcementofthecolumn
Foundationmeetsfoundation
Why is it better ?
• Rebarsofthecolumnhavetosetbeoutbeforelayingtherockfoundation• TheremustbeenoughspaceforL-shapedbottomendofrebars
Alternative:
• There’sneveranalternativetosolidfoundationmaterial
17GOODChapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Spaceleftforsettingoutthereinforcementofthecolumns
Height of foundations accordingtotherequirementsofthelocation–water,terrainetc
Spaceleftinfoundationforcolumns
Why is it better ?
• Rebarsofthecolumnhavetobesetoutbeforelayingtherocksofthefoundation
• TheremustbeenoughspaceforL-shapedbottomendofrebars• Thehigherthefoundationthelowertheriskofwaterdamage
Alternative:
• There’sneveranalternativetosolidfoundationmaterial
18 GOOD Chapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
Rock
Waterresistantcementforconcrete
Roughenedsurfaceoftoplayer
Awell-builtstripfoundation
Why is it better ?
• Concretewithwater-resistantcementavoidsmoistureinthewall• Awell-madefoundationisthebestbaseforabuilding• Roughsurfaceoftoplayerenablesbetterbondtobeams
Alternative:
• There’sneveranalternativetosolidfoundationmaterial
19GOODChapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
Concrete
Singleconcretefoundation
Foundationtrenchfilledwithrocks
Strings of Set Out
Single foundations instead of stripfoundation
Why is it better ?
• Singlefoundationforcolumnsareasolidbaseforelevatedfloorslabs
Alternative:
• Stripfoundationisanalternative• There’sneveranalternativetosolidfoundationmaterial
20 GOOD Chapter 02 Foundation
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
Concrete Production
Measure&mixtheingredientswithcare
Lettheconcreteslipintotheformwork
Why is it better ?
• Goodpreparationisessentialforgoodconcrete• Donotdroptheconcreteintotheformworkfromanyheight,butletitslip• Maximumdropofconcreteis5m,otherwisetheaggregatesgetseparated• Avoidcoldjointsduringpouring-doonesectioninonelift
Alternative:
• Thereisneveranalternativetogoodqualityworkmanship
23Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Formworknotparallelto rebars
Rebars are in a straight line
Coverof1–2cm
Watchthatconcrete“cover”isthesameoverentirelength
How can I do it better ?
• Keepthedistancebetweenrebarsandformworkconstant(minimalcover2cm)• Usecontinuousformwork• Fixthebottomedgeofformworkboardtokeepitstraight
Why ?
• Thestrengthofreinforcedconcretedependsontheproperinstallationofrebarsandformwork
24 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Distanceof2cm
Distanceofspacer
Distance(cover)of2cm
Spacer(blocks)underrebarskeeptherightdistancetotheformwork
How can I do it better ?
• Usespacer(suchasacementblock)tokeep“cover”distancebetweenrebarsandformworkconstant(2cm)
• Supportbeamformworkevery50cm
Why ?
• Spacersareessentialforensuringthecorrectandconstantconcretecover• Thestrengthofreinforcedconcretedependsontheproperinstallationofrebars
andformwork
25Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Distancefromrebarstoformworkistoolarge
Rebartouchesformwork
Spacer(block)onrebarswouldkeepthecorrect“cover”distancetoformwork
How can I do it better ?
• Usespacerblockstokeepdistancebetweenrebarsandformworkconstantfrom2cm
Why ?
• Therewillbenoconcretecover,i.e.thesteelbarswillbeexposed,whentherebarstouchtheformwork
• Spacersareessentialtoensurecorrectandconstantconcretecover• Thestrengthofreinforcedconcretedependsontheproperinstallationofrebars
andformwork
26 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Theremustbeaconnectionbetween these beams
Cutoffformworkbeforeconcreting
Thetwoconcretebeamsmustbecontinuous,includingtherebars
How can I do it better ?
• Cutopentheformworkbetweenthetwobeamssothattheyarecastasoneconnectedstructure
Why ?
• Jointsarealwaysaweakspotintheconcrete• Beamsuptoalengthof5mcanbecastinonepour
27Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Beamsupportevery50cmBeam supports are essential before concretingtheadjacentsection
Supportroofridgeandformworkforbeamfirst,thenstartconcreting
How can I do it better ?
• Supportformworkofconcretebeamsevery50cmuntilconcretereachesitsfullstrength
• Supportreinforcementbeforepouringtheadjacentsection
Why ?
• Duringpouringtherebarsmustnotmovednorvibrated
28 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
PourthebeaminoneliftSupport needed here
Avoidconcretinginshortsections
How can I do it better ?
• Solidlybuiltformworkisthebasisforstrongconcretestructures• Supportformworkofbeamsat50cmintervalsuntilconcretereachesitsfull
strength• Whencastingbeams(orcolumns)placeconcreteinonelift
Why ?
• Avoid“cold”concretejointsasmuchaspossible• Jointsarealwaysweakpointsofanyconcretestructure• Beamsuptoalengthof5mcanbecastinonepour
29Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
4sections!
3sections!
Cast all concretebeamsandcolumnsalwaysinonelift
Avoidpouringconcreteinshortsections
How can I do it better ?
• Solidlybuiltformworkisthebasisofgoodconcretestructures• Placeconcreteforallbeam(andcolumns)inonepour(lift)
Why ?
• Avoid“cold”concretejointsasmuchaspossible• Jointsarealwaysweakpointsinanyconcretestructure• Beamsuptoalengthof5mcanbecastinonepour
30 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
31Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
32 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Formworkforthecolumns
Bracesholdupformwork
Bracesholdupformworkforcolumns
Why is it better ?
• Strongformworkwillkeepitsshapewhenfilledwithwetconcrete• Bracketstiethesheets(orboards)oftheformworktogether• Formworkboardsarethickenough• Formworkforcolumnsisbracedfromtwosidestokeepitstraight
Alternative:
• Therearenoalternativestowell-builtformwork• Themoretimespentonbuildingformwork,thebettertheconcretewillbe
33Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
34 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Additionalbracingon top
Bracing
Brackets
Anchorforbrickwalls
Horizontalbracingprovidesmorestabilitytothecolumnformwork
Why is it better ?
• Bracingprovidesmorestabilitytotheformwork,soitcannotshiftortiltwhenthewetconcreteisplaced
• Leaveholesintheformworkforthewallanchors
Alternative:
• Concreteshallnotbedroppedmorethan5m,otherwisetheaggregateswillseparate
• Thereisnoalternativetogoodworkmanship
35Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Maximumheightis5m
Bracingatright angles
Bracingatright angles to eachother
Formworkfromtwosidesisessentialforverticalcolumns
Why is it better ?
• Theformworkcannotmoveduringconcreteplacement• Theformworkforcolumnsshallnotexceed5minheight• Heightbetweenhorizontalbeamsshallnotexceed3mtomakesurethe
structureisearthquake-proof
Alternative:
• Wetconcreteshallnotbedroppedmorethan5m,otherwisetheaggregateswillseparate
• Thereisnoalternativetogoodworkmanship
36 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
2directionbracesforcolumns
BracketsWoodenforms
Well-builtandstrongformworkforconcretebeamsandcolumns
Why is it better ?
• Strong,well-builtformworkisessentialforgoodqualityconcretestructures• Thethicknessofthesheetsofformworkisadequate–atleast2cmthick
Alternative:
• Thereisnoalternativetostrongformwork
37Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Supportsforbeamformwork
Solidsupportforformwork
Supportsforslabformwork
Why is it better ?
• Well-builtformworkisessentialforgoodqualityconcretestructures• Elevatedslabsorbeamsmustbesupportedat50cmspacingtoavoidsagging• DoNOTremovethebottomformworkandsupportsfor28days,sothatthe
concretewillreachitsdesignstrength
Alternative:
• Thereisnoalternativetostrongformwork
38 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Supports for beam forms
Roof beam
Formworkforroofbeamsmustbewellsupported
Why is it better ?
• Supportformsforbeamsat50cmspacinguntilconcretereachesitsstrength
Alternative:
• Thereisnoalternativeforstrongsupportsforformwork
39Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Roof beam
Beam supports shouldbeat50cmintervals
Wirecannotreplacesolidtiebrackets
Formworkforcolumn
Formworkforbeamsmustbewellsupported
Why is it better ?
• Supportformworkforbeamsat50cmspacinguntilconcretereachesitsstrength
• Usewoodentiebracketsinsteadofwire
Alternative:
• Thereisnoalternativeforgoodsupport
40 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Formwork
Concreterafter
Beam support
Formworkforconcreteraftersmustbesupported
Why is it better ?
• Supportformworksforbeamsat50cmspacinguntilconcretereachesitsfulldesign strength
Alternative:
• Thereisnoalternativeforgoodsupports
41Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Theserebarsshould overlap 50cm
50cmoverlap
TopLayerØ12mm12mm
TieØ8mm
BottomLayerØ12mm
Toplayer–redBottomlayer-green
Theremustbeaconnectionbetweenboththerebarsofthebottomandthetoplayerofreinforcement
How can I do it better ?
• Bendtherebarsasshownandfixthemtogetherwithwire• Lengthofoverlapmustbe40timesthediameter,oraminimumof50cm
Why ?
• Overlapisessentialtoextendthestrengthoftherebarsthroughoutthestructure
• Well-tiedandconnectedrebarsareabasicelementofreinforcedconcretestructures
• Fixingthereinforcementshouldbedonewithgreatcare
42 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Thisrebarshall overlap with the rebar crossingataright angle
50cmoverlap
Onlytoplayerismarked
50cmoverlap
Horizontalrebars
Theremustbeaconnectionbetweenboththeserebars(bottomandtoplayers)
How can I do it better ?
• Bendtherebarsasshownindrawing• Fixingthereinforcementmustbedonewithgreatcare
Why ?
• Well-tiedandconnectedrebarsareabasicelementofreinforcedconcretestructures
43Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
End of rebar must have a hook
50cmoverlaptonextrebar
Thesearetheoutlines of the rebars
Onlytoplayermarked
TheremustbeNO“dead”endofrebars–theymustbeconnectedtotheadjacentrebars in the same plane
How can I do it better ?
• Uselongerpiecesofrebars• Rebarmustneverendwithouta“U”hook• Bendtherebarsasshowninthepicture(anddrawings)• Fixingthereinforcementmustbedonewithgreatcare
Why ?
• Well-tiedandconnectedrebarsareabasicelementofreinforcedconcretestructures
44 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
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
How can I do it better ?
• Tierebarstogetherwiththin,flexiblewire• Eachrebarmustbetiedorconnectedtotheadjacentrebars
Why ?
• Onlywell-tiedrebarswillensurethestrengthoftheconcrete• Connectingtherebarsmustbedonewithgreatcare• Well-tiedandconnectedrebarsareabasicelementofreinforcedconcrete
structures
45Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Rebars must betiedtoeachother
ThereshallbeNOspacebetweenrebars
How can I do it better ?
• Bendtherebarsinaccordancewithwhat’sshownonthedrawings• Rebarshavetooverlapbyaminimumof50cm• Fixingtherebarsmustbedonewithgreatcare
Why ?
• Well-tiedandconnectedrebarsareabasicelementofreinforcedconcretestructures
46 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Rebars must betiedtoeachother
Rebars must betiedtoeachother
Design dimension of column
Rebarsmustbecenteredinconcretestructure
How can I do it better ?
• Theconcretecoverofrebarsmustbeatleast1-2cm• Eachrebarhastobeconnectedtotheadjacentone(s)• Fixingtherebarsmustbedonewithgreatcare
Why ?
• Adequateconcretecoverenablestheconcretetoreachitsdesignstrength
47Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
ThecrosssectionofthecolumnMUST NOT be less than the design
Rebars must be straightandvertical
BricksareNOT formwork
Rebarsmustbefixedinastraightverticallinefrombottomtotop
How can I do it better ?
• Rebarsforcolumnsmustbeinaverticalstraightlinefromthefoundationuptothe roof beam
• Thedimensionsofthecrosssectionofanycolumnorbeammustnotbereduced
• Thedimensionsofacolumnshallnotbelessthan15x15cm• BricksareNOTformwork
Why ?
• Thecolumnisakeyelementofthehousestructure• Columnscarrytheloadoftheentireroof• Areducedcrosssectionincreasestheriskofcollapseduringanearthquake• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarepotentiallyaffectedby
earthquakes
48 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Column rebars must be straight andvertical
Overlapofrebars50cmminimum
Foundationbeam
Foundation
RebarsofcolumnsmustbeSTRAIGHT,notbent
How can I do it better ?
• Rebarsforcolumnsmustbefixedtobeverticalandstraightfromthefoundationup to the roof beam
• Neverreducethedimensionsofthecrosssectionofanycolumnorbeam• Forcolumns,verticalrebarsmustbeaminimumdiameterof12mm,and
horizontalrebarsaminimumdiameterof8mm
Why ?
• Thecolumnisakeyelementofthehousestructure• Columnscarrytheloadoftheentireroof• Reducedcrosssectionsincreasetheriskofcollapseduringanearthquake• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarepotentiallyaffectedby
earthquakes
49Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Bentrebarsweakenthestabilityofthestructure
Column rebars must be straight andvertical
Rebars are not coveredinconcreteFoundationbeam
RebarsofcolumnsmustbeSTRAIGHT,notbent
How can I do it better ?
• Rebarsforcolumnsmustbeverticalandstraightfromthefoundationuptotheroof beam
• Thesizeofthecrosssectionofanycolumnorbeammustnotbereduced• Thedimensionsofacolumnshallnotbelessthan15x15cm• Forcplumns,verticalrebarsmustbeaminimumdiameterof12mm,and
horizontalrebarsaminimumdiameterof8mm• Concretecoveroverrebarsmustbe2cm
Why ?
• Thecolumnisakeyelementofthehousestructure• Columnscarrytheloadoftheentireroof• Reducedcrosssectionsincreasetheriskofcollapseduringearthquakes• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarepotentiallyaffectedby
earthquakes
50 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Thesedistancesarenotequal
Ties
Thedistancebetweentherebartiesshouldbeconstant
How can I do it better ?
• Fixrebartiesexactly15cmspacingfromeachother• Fixingthereinforcementmustbedonewithgreatcare
Why ?
• Rebarsareessentialforattainingthefullstrengthofareinforcedconcretestructure
51Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Twistedrebars
Rebarsmustbefixedstraightintheformwork
How can I do it better ?
• Rebarsmustbeplacedinastraightline• Usespacers(blocks)underrebarstogettherightcoveroverthesteelrebars• Fixingthereinforcementmustbedonewithgreatcare
Why ?
• Twistedrebarscannotdevelopthefullstrengthofthereinforcedconcretestructure
• Rebarsareakeyelementofareinforcedconcretestructure
52 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Rebars without spacers/blocks
Bottom formworkforslab
Nospacers/blocksareusedtoholdtherebarsintherightposition
How can I do it better ?
• Rebarsmustbesetonspacers/blockstogettherightconcretecover
Why ?
• Therearenoalternativestoproperlyfixedreinforcement• Themoretimeyouspendonfixingtherebarsandformwork,thebetterthe
concretewillbe
53Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Rebars sorted and stackedbysize
Rebarcagessortedandstackedonsupportstokeepthemclean
Productionofrebarcages
Assemblyandstorageofrebarsandcages
Why is it better ?
• Properlysortedandstackedrebarseasetheassemblyofrebarcagesaswellastheprogressofhouseconstruction
• Supportsunderthematerialskeeprebarsandcagesoffthegroundandclean
Alternative:
• Thereisneveranalternativetowell-organizedcleanstorage
54 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
55Chapter 03 Concrete Works GOOD
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Reinforcement
Foundationrebars–greenandblue
Allbluetiesareatthesamespacingof15cmoncenters Overlap50cm
Hook8cm Hook5cm
Column rebars-grey
Exampleofabeam&columnrebars(Coloursforillustrationonly)
Why is it better ?
• Correctlysizedandfixedrebarsareimportanttoreachingthedesignstrengthofreinforcedconcretestructures
• Allrebarsmustbeclean,freeofrustandtiedtoeachother
Alternative:
• Therearenoalternativestoproperlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
56 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Alltiesareatequalspacing
Nospacerblocksareused-yet
Rebarsarefixedproperly
Why is it better ?
• Correctlysizedandfixedrebarsareimportantforreachingthestrengthofreinforcedconcretestructures
• Allrebarsmustbetiedtoeachother• Tieslocationsarevaried• Usespacerblocksbelowrebarstoensurecorrectconcretecover
Alternative:
• Therearenoalternativestocorrectlysizedandfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
57Chapter 03 Concrete Works GOOD
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Reinforcement
15cmspacingasper design
Ø12mm
Overlap50cm
Ø8mm
Rebarsareneatlyassembledbutspacerblocksarenotused-yet
Why is it better ?
• Thelengthofoverlapshallnotbelessthan50cm• Correctlysizedandfixedrebarsareimportantforreachingthedesignstrength
ofreinforcedconcretestructures• Allrebarsmustbetiedtoeachother
Alternative:
• Therearenoalternativestoproperlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
58 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
BricksareNOTformwork
Equalspacingbetween ties
Overlap50cmwith the rebars of foundation
Correctlyandneatlyinstalledrebars
Why is it better ?
• Correctlyfixedrebarsareimportantforreachingthestrengthofreinforcedconcretestructures
• Allrebarsmustbetiedtoeachother
Alternative:
• Therearenoalternativestocorrectlysizedandfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
59Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Adequateconcretecover
Column rebar wellcenteredon beams
Equalspacingbetween ties
Notetheconcretecover
Why is it better ?
• Concretecovermustbeatleast2cmtomakesuresteelrebarsarenotexposed• Allrebarsmustbetiedtoeachother
Alternative:
• Therearenoalternativestoadequateconcretecoveroverreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
60 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
ColumnrebarsØ12mm
TiesØ8mmspacedat15cmapart
90°AngleRebars bent into footing about 70to80cm
Fixingtheverticalcolumnrebarsinthefoundationtrench
Why is it better ?
• Alargefootingprovidesagoodbaseforthecolumnreinforcement• Bendthecolumnrebarsatan90°angleintothefooting• Rebarsarecleanandnotrusty
Alternative:
• Therearenoalternativestocorrectlyandneatlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
61Chapter 03 Concrete Works GOOD
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Reinforcement
Correctlyassembled rebars
Rebarcageforafootingpadforanelevatedfloor
Why is it better ?
• Rebarsarecorrectlyandneatlyfixedinplace• Rebarsarebentatanexact90°angle
Alternative:
• Therearenoalternativestocorrectlyandneatlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
62 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
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:
• Therearenoalternativestocorrectlyandneatlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
63Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Supports at right angle
Column rebars
Supports at right angle
Supportsfromtwosidestokeeptherebarsvertical
Why is it better ?
• Therebarsmustnotmoveduringconcreting• Rebarsmustbetrulyverticalsothatthecolumnwillbeperfectlystraight
Alternative:
• Therearenoalternativestogoodreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
64 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Reinforcement
Rebarstoconnecttoreinforcementtoroof ring beams
Anchorsforbrickwallconnections
Steelanchorsarenecessarytotiethebrickwalltotheconcretecolumns
Why is it better ?
• Anchorstiethebrickwalltotheconcretecolumns• Columnsandwallsarebothelementsofthestructuralsystemandareessential
forthestrengthandstabilityofthehouse
Alternative:
• Therearenoalternativestocorrectlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
65Chapter 03 Concrete Works GOOD
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Reinforcement
Anchorsforwallconnections
Rebars of lintel ring beam
Rebarsforconnectingto lintel ring beam
Rebars for connectingtoroof ring beams
Rebarconnectionstobeamsandwall
Why is it better ?
• Allstaticelementshavetobeconnectedtothestaticsystemofthebuilding• Allrebarshavetobeconnectedtoeachother
Alternative:
• Therearenoalternativestocorrectlyandneatlyfixedreinforcement• Themoretimespentonreinforcement,thebettertheconcretewillbe
66 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Lintels missing
Bricksusedasformwork
Columns were castin3sections
Solidframeworkisessential
How can I do it better ?
• Firstpourtheconcretecolumnsuptotheroofbeam(beforebuildingthewalls)• Checksteelreinforcement• Usecontinuousformworkfortheentirecolumn• Buildthebrickwallsafterformworkhasbeenremoved
Why ?
• Thestrengthofaconcretecolumnincreaseswiththesizeofitscrosssection.• Acolumnthatistoolongrelativetoitscrosssectioncanbuckleunderheavy
loads.
67Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Max.load bearingcrosssectionof columnasactuallybuilt
Required designcross sectionofthe
column
Fulldesigncrosssection
of the column
Columnsmusthavethedesigncrosssectionalongtheirentirelength
How can I do it better ?
• Useplywoodformworkinsteadofusingthebricksasformwork• Thedimensionsofanycolumnshallnotbelessthan15x15cm• BrickworkisNOTformwork!
WHY ?
• Thecolumnisthekeybearingelementofthehousestructure• Columnshelpholdupthewallsandcarrytheloadoftheentireroof• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofcolumnsareeasilyaffectedbyearthquakes
68 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Rebars must be vertical
ACTUALcross sectionforcarryingload
Designcross sectionreq’d
Columnsmusthavethedesigncrosssection
How can I do it better ?
• Thedimensionsofaconcretecolumnshallnotbelessthan15x15cm• Useplywoodformworkinsteadofusingthebricksasformwork• BrickworkisNOTformwork!• Rebarsmustbefixedinaverticalposition
WHY ?
• Thecolumnisthekeybearingelementofthestructureofahouse• Columnshelpholdupthewallsandcarrytheentireloadoftheroof• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarelikelyaffectedby
earthquakes
69Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Uppersection ofthecolumn
Actualloadbearingcross section
Lowersectionofthecolumn
Design load bearing crosssection
Thefulldesigncrosssectionofacolumnisessentialforthestrengthandstabilityoftheentirestructure
How can I do it better ?
• Thedimensionsofacolumnshallnotbelessthan15x15cm• Usecontinuousformworkfortheentirecolumn• Useplywoodformworkinsteadofusingthebricksasformwork• BrickworkisNOTformwork!
WHY ?
• Thecolumnisthekeybearingelementofthestructureofahouse• Columnshelpholdupthewallsandcarrytheentireloadoftheroof• Columnsmustbebuiltwithgreatcare• Thestabilityandstructuralintegrityofthecolumnsarelikelyaffectedby
earthquakes
70 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Reinforcingbarsarenotcoveredbyconcrete
Thiscolumncannot carryanyloadatall
Concreteisnotwellcompactedandthecolumnsarecompletelyoutofshape–theactualcrosssectioncannotcarryanyloads
How can I do it better ?
• Rebarsmustembeddedinwell-compactedconcrete• Coveroverreinforcementmustbeaminimumof2cm
WHY ?
• Everybeamorcolumnisaload-bearingelementinthesystemofahouseandhastobecarriedoutverycarefully
• Concretewillneverreachfullstrengthwhenitisnotwellcompacted• Reinforcementandtheconcretearounditconstitutethestrengthofthebeam/
column
71Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Noconcrete inthecolumn
No Cover on rebars
No Cover on rebars
Thesecolumnscannevercarryanyloads!
How can I do it better ?
• Makesurethattheconcreteiswell-compacted• Usesolidformworkonly–bricksarenotformwork• Watchoutthatthereinforcementhasaminimumcoverof2cm
WHY ? • Onlythejointactionofreinforcementandconcretewillmakestrongcolumns
andbeamstogetarigidandstableload-bearingsystem.• Earthquake-proofsystemneedsarigidframework
72 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Honeycombs
Honeycombsshowinglesscompactionduringpouring
How can I do it better ?
• Compacttheconcretewellduringtheentirepouring
WHY ?
• Onlywell-compactedconcretehasstructuralstrength• Theconcreteframeispotentiallyaffectedbyearthquakes,thereforefull
attentionhastobegiventotheconcreteworks
73Chapter 03 Concrete Works BAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Poormixingof aggregates
Honeycombs
No bonding betweenfoundation and beam
Rebars twisted
Not enoughcompaction
Honeycombsweakenthestrengthofconcrete
How can I do it better ?
• Compactconcreteoftenandwithcareduringpouring• Makesurethatconcreteaggregatesdonotgetseparated
WHY ?
• Onlywell-compactedconcreteachievesthenecessarystrength• Theconcreteframeofcolumnsandbeamsispotentiallyaffectedby
earthquakes,thereforeconcreteworksmustbedonewithgreatcare
74 Chapter 03 Concrete WorksBAD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Continuation ofcolumn
King postof truss is inclined
Should be in the
same spot
Kingpostshouldbeplacedstraightontopofthecolumn
How can I do it better ?
• Movethekingposttothetopofthecolumn
WHY ? • Theverticalloadonthekingpostshouldbetransferreddirectlytothecolumnsand
foundation• Theconcreteframeispotentiallyaffectedbyearthquakesthereforetheconcrete
worksmustbedonewithgreatcare
75Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Foundation beams are well-builtAsolidstone
foundation
Thiswell-shapedfoundationgridisasolidbaseforthehousestructure
Why is it better ?
• Asolidfoundationisthebestbaseforahouse • Buildastronggridoffoundationbeamstogetastrongstructure
Alternative:
• Thereisnoalternativeforagoodfoundation
A solid stone foundation
76 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Brickwork foundation
Foundation beamsFill must be
compacted
Foundationbeamswerecastwithgoodformwork
Stone foundation
Foundation beams
Why is it better ?
• Strongformworkhelpstoachievethefullstrengthoftheconcretesothatthestructurecanresistearthquakes
Alternative:
• Thereisnoalternativeiffullconcretestrengthshouldbeattained
77Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
78 Chapter 03 Concrete WorksGOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
79Chapter 03 Concrete Works GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Beams & Columns
Inner edge of column
Outer edge of column
Column built with formwork
Why is it better ?
• Askeleton(framework)isessentialforanearthquake-proofbuilding
Alternative:
• Thereisnoalternativeforbuildinggoodqualitystructure
80 Chapter 03 Concrete WorksGOOD
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Beams & Columns
Wallanchors
Foundationbeamsandcolumnswithwallanchorsbuiltusinggoodformwork
Why is it better ?
• Goodformworkisessentialforanearthquake-proofbuilding • Afterremovaloftheformwork,thebricklayingcanstart
Alternative:
• Thereisnoalternativeforgettinggoodqualityconcrete
81Chapter 03 Concrete Works GOOD
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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
82 Chapter 03 Concrete WorksGOOD
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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
THE GOOD & THE BAD INFRASTRUCTURE
Materials
Untidystorageofbricks
How can I do it better ?
• Stackbricksneatly–thereislesschanceofbreakage
WHY ?
• Brokenbricksmakeweakerbrickwalls
84 Chapter 04 WallsGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Materials
Brickstorage
Concretebricksofstandard dimensions
Left:Wellstackedclaybricksofstandarddimensions,i.e.20x10x5cm
Why is it better ?
• Well-storedbrickswillnotgetbrokenandbricklayingwillbeeasier
Alternative:
• Wallsmadeofhollowconcreteblocks
85Chapter 04 Walls BAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Brokenbricks
Defective,brokenandpoorqualitybricksweakenthewall
How can I do it better ?
• Bricksofgoodqualitymakesforstrongerwalls • Handlebrickswithcareandstackthemintidypilesonthestoragearea
WHY ?
• Bricksaremadeoffiredclayandbreakeasily • Bricksgettheirstrengthwhenlaidincementmortarinmasonrywalls
86 Chapter 04 WallsBAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Thejointsareaswide asthebricks!
Thejointsaretoolarge
How can I do it better ?
• Makevertical&horizontaljointsonly1.0to1.5cmwide • Thebricksmustbelaidperfectlylevel
WHY ?
• Widejointsarenotgoodforthestabilityofthewall
87Chapter 04 Walls BAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Horizontal Line
Brickcoursesarenot level
Brickcoursesarenot level
Bricksnotlaidlevel,i.e.notinahorizontalline
How can I do it better ?
• Thejointsmustbebetween1.0and1,5cmmaximum • Thebrickshavetobelaidlevel,i.e.inahorizontalline
WHY ?
• Unevenjointsandbrickworknotlaidlevelmayaffectthestabilityofthewall
88 Chapter 04 WallsBAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Brickjointsarenot
Bricksmustlaid leveland with
Edge of brickwork
Bricksmustlaid leveland with
NOanchorswere used
Design width ofcolumn
Thiswallshowsmanydefects
How can I do it better ?
• Thiswallmaynotwithstandanearthquake • Followthesuggestionsinthisbookforbuildingbrickwalls • Firstcasttheconcretecolumnsandthenstartwiththebricklaying • Bricksmustbelaidlevelandplumb,andthejointsmustbeoffsetbyhalfabrick
lengthIeachlayer • Thesteelanchorsfromthecolumnsmustbeembeddedinthebrickwall
WHY ?
• UsingGOODconstructionpracticeasshowninthisbookwillresultingoodqualityhouse
89Chapter 04 Walls BAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
ToppartofwallisOK
Jointsbetweenbricksare too wide
Bricksmustbelaidexactlylevel
How can I do it better ?
• Setbricksexactlylevel,i.e.inahorizontalline • Thejointsmustbethesamewidth,i.e.1.0to1,5cmmaximum
WHY ?
• Awellbuilt,solidwallcontributestothestabilityofthehouse • Itiseasiertoputplasteronasmoothbrickwall
90 Chapter 04 WallsBAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Unevensurface
Bricksusedasalternative tostonesorrocks
Evensurface
Bricksmustbelaidexactlyaligned(ontopofeachother)togetasmoothwallsurface
How can I do it better ?
• Laybrickswithaplumblinetogetaperfectlyverticalline
WHY ?
• Awellbuiltbrickwallcontributestothestabilityofthehouse • Itismucheasiertoputplasteronasmoothwallsurface
91Chapter 04 Walls BAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Beam is sagging
Design width of columns
Edge of wall
Bricksarenotlevel
Wallshouldbebuiltaftercolumnshavebeenbuilt
How can I do it better ?
• Buildthebeamfirst(withgoodsupports),thenbuildthecolumns,andlastthebrickwall
WHY ?
• Buildingintherightsequenceisimportantforagoodqualityhouse
92 Chapter 04 WallsBAD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Brickscandistribute load
better when laidlikethis
Load of the wall above
BricksareOKon this side
Center line
Thisishowabricklintelcouldbebuilt
How can I do it better ?
• Laythebricksforthelintelasshownonthepictureabove
WHY ?
• Alintelmustcarryanddistributetheloadofthewallabovetheopeningtotheadjacentwallsandcolumns(whichcarrytheloadtothefootings)
93Chapter 04 Walls GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Jointsshouldbe 1.0to1.5cm
Connectionto column
Claybrickwall
Why is it better ?
• Thejointsmustnotexceedthedimensionsshown • Thebricksofthenextlayeruparelaidcenteredonthejointofthelowerlayer • Thejointtothecolumnisexecutedneatly
Alternative:
• Wallmadeofhollowconcreteblocks
94 Chapter 04 WallsGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Theindicatedareaisto12m2 max.
Max.heightbetweenbeams 3m
Areabetweencolumnsandbeamsshallnotexceed12m2
Why is it better ?
• Areaslargerthan12m2willnotresistevenmoderateearthquakes • Forstabilityreasonsitisveryimportantthattheanchorsfromthecolumnsare
embeddedinthebrickwork
Alternative:
• Thereisnoalternativeforbuildingstablewalls
95Chapter 04 Walls GOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
96 Chapter 04 WallsGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Wallanchors
Foundationbeams
Columns
Anchorgetsembedded in brickwork
Connectionofcolumntobrickwall
Why is it better ?
• Theconnectionmustbedonewithcare • Tomaketheconnectioneffective,itisimportantthatthesteelanchorsare
embeddedinthebrickwork
Alternative:
• Thereisnoalternativetogoodwallanchors
97Chapter 04 Walls BAD
THE GOOD & THE BAD INFRASTRUCTURE
Doors & Windows
Supports
Foundationbeamnotyetpoured
Door frames
Door&windowframesmustnotbeinstalledbeforetheconcreteworkhasbeenfinished
How can I do it better ?
• Buildcolumnsandbeamsbeforestartingbrickwork
WHY ?
• Itispreferabletofinishallconcreteworksfirstandthenstartwithwallconstructionandthendothedoorandwindowinstallation.
98 Chapter 04 WallsBAD
THE GOOD & THE BAD INFRASTRUCTURE
Doors & Windows
Lintelbricksshall be laid in two directions
Window frames
Edge of wall before window installation
Jointshouldbedonewithcare
Windowframemustbeinstalledbeforebuidingthewall
How can I do it better ?
• Installthewindowanddoorframestogetherwithbuildingthewall • Bricksforlintelshouldbesetintwodirections(similartoanarch) • Keepasmallspacebetweenwallandframesandfillitwithmasonry
WHY ?
• Agooddesignminimizesproblemsonsite
99Chapter 04 Walls GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Doors & Windows
Door frames
Windowframes
Framesreadyforinstallation
Why is it better ?
• Framesarestackedforstorage(theyshouldbeonsupports)
Alternative:
• Goodpreparationandorganizationeasestheprogressofwork
100 Chapter 04 WallsGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Doors & Windows
Temporary supports
Windowframes
Windowframesreadyforinstallation
Why is it better ?
• Temporarysupportsholdandfixtheframesinanuprightpositionduringconstruction
Alternative:
• Goodpreparationeasestheprogressofwork
101Chapter 04 Walls GOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
102 Chapter 04 WallsGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Doors & Windows
Supportsoutside building
Spacer
Corner brace keeps framerectangular
Louvres above window
NO lintelbeam
Supportscanalsobeinstalledoutsidethestructure
Why is it better ?
• Supportsholdtheframesinaverticalpositionduringtheconstructionofthewalls
• Spacerskeeptheframeinalevelpositionduringwallerection
Alternative:
• Therearenone–goodtemporarysupportsareessential
103Chapter 04 Walls GOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
104 Chapter 04 WallsGOOD
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Doors & Windows
Lintel
Lintel included in roof beam
Alintelhastocarrytheloadofthewallabove
Why is it better ?
• Bricksinlintelareinclinedinbothdirections • Roofbeamisextendeddowntotopedgeofwindowframe
Alternative:
• Lintelscanbebuiltofbricksorofconcrete • Useconcretelintelbeamwhenverticaldistancetoroofbeamexceeds50cm
105Chapter 04 Walls GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Plaster
60cmofwater-resistant plaster
Plastermakesasmoothwallsurface
Why is it better ?
• Topreventmoisturefrompenetratingthewallsthelower60cmofwallsshouldbeplasteredwithawater-resistantplaster(1,5unitsinsteadof1,0unit)
Alternative:
• Tarpaperorplasticsheetscanbelaidontopoffoundationbeamtopreventmoisturefrompenetratingthebricks
106 Chapter 04 WallsGOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
107Chapter 04 Walls BAD
THE GOOD & THE BAD INFRASTRUCTURE
Roofing Materials
Notwellfixedto the purlins
Sheetshavetobefixedreallywell
How can I do it better ?
• Onlyproperlyinstalledandsealedroofingmaterialsguaranteealeak-proofroof • Improperlyfastenedorlooseroofingmaterialsposeaseriousriskduringstorms
WHY ?
• Thereisnoalternativetogoodworkmanship
108 Chapter 04 WallsBAD
THE GOOD & THE BAD INFRASTRUCTURE
Roofing Materials
NOrubbersealused
Nail on top of roof ridges
Rubbersealisneededforaleak-proofroofNotethelargeheadoftheroofingnail
How can I do it better ?
• Userubbersealsaroundtheroofingnailsorscrews • Putnailsonthetopofridges
WHY ?
• Thereisnoalternativeofgoodworkmanship
109GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
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
111GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Roofing Materials
Nailed to purlin
Rubber sealunderplasticcovercap
Usenailswithaplasticcap
Why is it better ?
• Theremustbearubbersealbetweenroofingsheetandroofingnails(orscrews) • Galvanizedorstainlesssteelmaterialsshouldbeusedbecausetheydonotrust
Alternative:
• Roofingtiles,buttheyaremuchheavierandmoreexpensive • Fibrecementsheets • Galvanizedsteelsheetsarecurrentlythecheapestroofingmaterial
112 Chapter 05 RoofBAD
THE GOOD & THE BAD INFRASTRUCTURE
Aluminum Construction
Rafter
Tiebeam
Purlin
No truss connectiontothe ring roof
beam
Trussmustbefixedtoroofringbeam
Why is it better ?
• Rigidandstrongconnectionsareessentialforastableroofframe
Alternative:
• ThetraditionallyusedmaterialisstillwoodanditisagoodalternativeAluminumConstruction
113GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Aluminum Construction
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.
114 GOOD Chapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Aluminum Construction
Rafter
PurlinTiebeam
Solidconnection to roof ring
beam
Aluminumtrussconnectiontoroofringbeam
Why is it better ?
• Allrooftrussesmustbetiedtotheroofringbeam
Alternative:
• Woodisstillagoodalternative
115GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Aluminum Construction
Rafter extension
Frontboard
Purlin
Aluminumtrussdetailwithwoodenextensionforfixingwoodenfrontboard
Why is it better ?
• Itiseasiertofixthefrontboardtothewoodenrafterextensions
Alternative:
• Woodenrooftrussesarestillagoodalternative.
116 Chapter 05 RoofBAD
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Thiswireis not enoughtofix
the rafter to the wall
Theraftermustbe supported on entire
length of the wall
Wellsupportedraftersimprovethestabilityoftheroof
How can I do it better ?
• Buildthewallallthewayuptotherafter,sothesupportisoveritsentirelength • Useflatsteel(plates)andboltstofixtheraftertothewall
WHY ?
• Thebettertheraftersaresupported,thestrongertheroofconstructionwillbe • Raftersneedtobesupportedwhentheyarenottiedtogetherbythetiebeam
117Chapter 05 Roof BAD
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Trussnotfixedtotheroof ring beam
Rafter Purlin
TieBeam
WallPlate
Theentirerooftrussmustbefixedtotheroofringbeam
How can I do it better ?
• Useflatsteel(plates)andboltstotiethetrusstotheroofringbeam
WHY ?
• Thebettertheconnectionofthetrusstothewall,thestrongertheroofconstructionwillbe.
118 Chapter 05 RoofBAD
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
y
Rafter
s
Tiebeamextensionandkingpostnailed together onl
Trussnotfixedtoroof ring beam
Cross Beam
Makesurethattherooftrussisproperlyconnected
How can I do it better ?
• Boltsarebetterthanjustnailsforalltrussconnections • Useflatsteel(plates)andboltstotiethetrusstotheroofringbeam
WHY ?
• Thebettertheconnectionsofthetrusstothewall,thestrongertheroofconstructionwillbe.
119Chapter 05 Roof BAD
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Cross beams
Thisisno alternative to angle struts
TiebeamAnglestrut
Arooftrusswillreachitsfullstrengthwhenallmembersaretiedtogether
How can I do it better ?
• Useproperanglestrutsinsteadofunapprovedconnectionstothewall
WHY ?
• Arooftrussisastructuralsystemandcanonlyfunctionassuchwhenallmembers are tied together
• Thebettertheconnectionsofthetruss,thestrongertheroofconstructionwillbe.
120 Chapter 05 RoofBAD
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Purlin
Anglestrut
Secondary post
Theconnection should bethe other
wayround
RafterExtension
ConnecttheextensionONTOPoftherafter
How can I do it better ?
• Theextensionmustbemountedon top oftherafterandmustbeconnectedwithatleast2boltsthroughbothmembers
WHY ?
• Bothmembersmustfunctionlikeonestructuretocarrytheloadoftheroof • Thebettertheconnectionsofthetruss,thestrongertheroofconstructionwill
be.
121GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Assembled stackedtrusses
Stackedtimber Productionofroof
trusses
Productionofrooftrusses
Why is it better ?
• Timbersortedandstackedbysizeeasetheproductionofrooftrussesaswellastheprogressofhouseconstruction
Alternative:
• Thereisneveranalternativeforagoodorganisationonaconstructionsite.
122 GOOD Chapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Crossbeams
Anglestrut
Bottom tie beam
Purlin
t
Uppertiebeam
Bolts for good connectionsKingpos
Themainpartsofarooftrussframe
Why is it better ?
• Well-builtrooftrusseswillresistwindstormsandearthquakes
Alternative:
• Thereisnoalternativeforgoodworkmanship
123GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Connectionofkingpostandtiebeamwithboltsonly
Connectraftersectionswithboltsonly
PurlinKingPost
Connecttiebeamsectionswith bolts
Howconnectionsofwoodentrussmembersshouldbemade
Why is it better ?
• Theconnectionsofthewoodentrussmembersmakeitarigidframe • Boltsconnectionsaremuchbetterandstrongerthannails • Boltsarescrewedthroughbothwoodensectionsandtiethemtogether
Alternative:
• None
124 GOOD Chapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Kingpostconnections
Truss
Crossbeamsfixedtothekingspostsmakethestructurestable
Why is it better ?
• Thetrussesmustbetiedtogetherwithtwocrossbeamstoconnectthetrussestoeachother
• Thecrossbeamsstabilizethetrussesvertically • Boltedconnectionsarebetterthannails
Alternative: • None
125GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
s Secondcrossbeamnotyetinstalled
Trusse
Rigidconnectionbetweentrussand roof ring beam
Thepictureshowswherethetrusseshavetobeconnected
Why is it better ?
• Tightconnectionsareimportanttomakethetrussesstrong
Alternative:
• Thereisnoalternativetogoodworkmanship
126 GOOD Chapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Boltsoneachsideoftruss areembeddedinconcreteroof beam
Rafter
Flatsteelplate connectsthebolts
Tiebeam
Concrete roof beam
Thetrussmustbemountedon,andfixedto,theroofringbeam
Why is it better ?
• Tightconnectionsbetweentrussandconcreteroofringbeamareessentialforastrongconstruction
• Boltsfastentheflatsteelplatetightlytothebeam
Alternative:
• Bentrebarsofthecolumncanalsobeusedtotiethetrussestoroofbeam,buttheymustbefixedtothetruss
127GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
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
128 GOOD Chapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Rebarssetinconcrete, bent&fixedtothepurlin
Concreterafters
Purlinsmountedonconcreterafters
Why is it better ?
• Tightconnectionsareimportanttokeepthepurlinsinplacefortheroofing • Spacingofpurlinsdependsonroofingmaterials
Alternative:
• Thereisnoalternativetogoodworkmanship
129GOODChapter 05 Roof
THE GOOD & THE BAD INFRASTRUCTURE
Wood Construction
Purlinsupportmounted on a wooden rafter
Goodinstallationfor rafterextension
Goodexamplesofrooftrussframeconstruction
Why is it better ?
• Tightconnectionsareimportanttoholdthepurlinsinplacefortheroofing • Theconnectionofrafterextensionsmustbedonewithcare–atleast2bolts
mustbeusedthroughbothwoodensections
Alternative:
• Thereisnoalternativetogoodworkmanship
FloorChapter 06
131Chapter 06 Floor GOOD
THE GOOD & THE BAD INFRASTRUCTURE
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
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Backfill(soil) readyfor
compaction
Compactedbackfillisthebaseforthefloorconstruction
Why is it better ?
• Althoughcompactionhasnetbeendoneinthislayers,butwell-compactedbackfillpreventslatersettlingoftheconcretefloorslab
Alternative:
• Themoretimespentonplacingthedifferentfloorlayer,thebettergetsthequalityofthehousewillbe
133Chapter 06 Floor GOOD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Wellcompactedandlevelledbackfill
Backfillisthebaseforthefloorconstructionandmustbewellcompacted
Why is it better ?
• Compactiontobedoneforeachlayerofbackfill • Layersofbackfillshallnotexceed20cmindepth • Whenthebackfilliswellcompactedtheconcretefloorslabcannotsettleor
crack
Alternative:
• Themoretimespentoncompacting,thesmallertherisksoffloorsettlementsorcracking
134 Chapter 06 FloorGOOD
THE GOOD & THE BAD INFRASTRUCTURE
Construction
Well executed floor slab construction
Floorslabisthebaseofthefinishedfloor
Why is it better ?
• Thesurfaceissmoothandwelllevelled • Thisisgoodbaseforfloortiles,linoleumorjustpaintingthesurface
Alternative:
• Thereisnoalternativetogoodworkmanship
ServicesChapter 07
135Chapter 07 Services BAD
THE GOOD & THE BAD INFRASTRUCTURE
Electricity
Cablemayrubatthe edgeofcolumn
Wiresfixedonplasteronly
Avoidcablescomingintocontactwithsteel
elements
Cablesshouldbeinstalledinplastic(PVC)ducts
How can I do it better ?
• Forincreasedsafety,electricalwiresshouldbeinstalledinPVCducts • Installtheductsinastraightlineundertheplaster–itmakesiteasiertofindthem
later on • Preferably,electricalwiresshouldbeinstalledoutofreach,i.e.higherthan2,5m • Inmasonrywalls,theductsshouldbeinstalledinthewalloratleastinthe
plaster,inwoodenstructurestheductsareinstalledonthesurface
WHY ?
• Asafeelectricalinstallationshouldpreventsystemfailuresandalsobenothreattohumanhealthandsafety
136 Chapter 07 ServicesBAD
THE GOOD & THE BAD INFRASTRUCTURE
Electricity
Avoidductscrossingsthrough beams
Betterlocationfordistribution line
Cablesclampsaregood
Wireductshavetobefixedtothewall
How can I do it better ?
• Minimizepenetratingbeamswithductstoavoidweakeningofthebeam • Electricalwiresandductsshouldbeoutofhumanreach,higherthan2,5m
WHY ?
• Asafeelectricalinstallationpreventssystemfailuresandshouldmeethumanhealthandsafetyrequirements
137Chapter 07 Services BAD
THE GOOD & THE BAD INFRASTRUCTURE
Electricity
ExtendtheductbelowtheceilingInstallahookto
taketheweightof thefixture
Cablemayrubon sharp edge of
ceiling
Installationofelectricalfixturebelowtheceiling
How can I do it better ?
• Electricalcablesshallnotrubattheedgeofthesuspendedceiling • InstallwiresinaPVCductthatextendsbelowthesuspendingceiling
WHY ?
• AfaultyelectricalInstallationcouldcausedamagetothehouse • Apoorinstallationisalsoarisktohumanhealthandsafety
138 GOOD Chapter 07 Services
THE GOOD & THE BAD INFRASTRUCTURE
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
139Chapter 07 Services BAD
THE GOOD & THE BAD INFRASTRUCTURE
Water & Sanitation
Pipe outlets
Never penetrate a beam with a larger pipe
How can I do it better ?
• Neverpenetratebeamswithanylargerpipetoavoidweakeningthebeam • Set water and sanitation pipes below natural ground level • Crossfoundationabout60cmbelowgroundlevel
WHY ?
• DoNOTweakenthestrengthofaconcretebeam–itisanimportantelementoftheearthquake-proofstructure
• Pipeslaidbelowgroundarebetterprotectedagainstdamageordestruction
140 GOOD Chapter 07 Services
THE GOOD & THE BAD INFRASTRUCTURE
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