轻型木结构构造细节

CanadaWoodLevel1-Wood-FrameConstructionConstructionDetailsHerbertOtto,B.Arch.,MRAICFoamBoardSheathingAirBarriersExtrudedpolystyreneor

facedfoamboardinsulatedsheathingssealedatalljointsandpenetrationsandsealedtoceilingandfoundationairbarriersSealingoptionsGasketsUrethanesprayfoamCompatibledurabletapeMusttieintoceilingandfoundationairbarriersFoamBoardSheathing

AirBarrierMaterialsExtrudedpolystyrenefoamboardFoilfacedpolyisofoamboardinsulationFoamedpolyethylenesillgasketAluminumfoiltapewithacrylicadhesiveContractor’ssheathingtapeorpeelandsticktapeNailswithlargeplasticwashersFoamBoardSheathing

AirBarriersGasketedjointSillgasketstapledtowoodframingatjointlocationShiplapXPSnailedatjointintowoodframingcompressinggasketGasketsealsusedatroughopeningsandwindowanddoorframessealedwithsprayfoamFoamboardsealedtowalltopandbottomplatesforconnectiontofoundationandceilingairbarrierFoamBoardSheathingAirBarriersProvidesadditionalinsulationvaluetothewallassemblyReducesthermalbridgingthroughframingIfthefoamboardhasalowwatervapourpermeabilitywithoutcavityinsulationthiswallassemblycanbeusedsafelyinanyclimateintheworld.TapedfoamboardsheathingairbarrierAirBarrierandVapourBarriersbyClimateClimatesrequiringheatingthemajorityoftheyear.AirbarrierlocationCanbelocatedanywhereintheassemblyifvapourpermeableIfvapourimpermeablemustbelocatedonortowardsthewarmsideoftheinsulationVapourBarrierMustbelocatedonortowardsthewarmsideoftheinsulationInmostcoldclimatesmaybelocatedpartiallyinsidewallwith2/3oftheinsulationoutsidethevapourbarrierInarcticregions4/5’softheinsulationmustbeplacedoutsidethevapourbarrier.2/31/3PossibleAirBarrierLocationsPossibleVapourBarrierLocationsOutsideInsideCladdingWRBSheathingInsulationInteriorFinishDrainage/VentilationPlaneAirBarrierandVapourBarriersbyClimateMixedclimatesrequiringheatinginthewinterandcoolinginthesummerAirbarrierlocationCanbelocatedanywhereintheassemblyifvapourpermeableIfvapourimpermeablemustbelocatedatthecentreofthewallVapourBarrierMustbelocatedatthecentreofthewallInteriorandexteriorfinishesvapourpermeabletoallowdryingtooutsideinwinterandinsideinsummerPossibleAirBarrierLocationsVapourBarrierLocation1/21/2OutsideInsideCladdingWRBSheathingInsulationInteriorFinishDrainage/VentilationPlaneAirBarrierandVapour

BarriersbyClimateMixedclimatesrequiringheatinginthewinterandcoolinginthesummerAirbarrierlocationCanbelocatedanywhereintheassemblyifvapourpermeableIfvapourimpermeablemustbe

locatedatthecentreofthewallVapourBarrierMustbelocatedatthecentreofthewall.Inthisexamplethevapourbarriercanbeprovidedbyalowpermeancefoamboardinsulation(XPSorfoilfacedurethane)orawaterproofWRBwillactasthevapourbarrierInteriorandexteriorfinishesvapourpermeabletoallowdryingtooutsideinwinterandinsideinsummerPossibleAirBarrierLocationsVapourBarrierLocationsOutsideInsideCladdingWRBLowpermfoamboardjointstapedSheathingInsulationInteriorFinishDrainage/VentilationPlaneAirBarrierandVapour

BarriersbyClimateHothumidclimatesrequiringcoolingallyearAirbarrierlocationCanbelocatedanywhereintheassemblyifvapourpermeableIfvapourimpermeablemustbelocatedattheoutsideofthewallVapourBarrierMustbelocatedattheoutsideofthewallInteriorfinishvapourpermeabletoallowdryingtoinsidePossibleAirBarrierLocationsVapourBarrierLocationOutsideInsideCladdingWRBSheathingInsulationInteriorFinishDrainage/VentilationPlaneAirBarrierandVapour

BarriersbyClimateAllclimatesAirbarrierlocationCanbelocatedanywhereintheassemblyifvapourpermeableIfvapourimpermeablemustbeformedbythelowpermeancefoamboardinsulationVapourBarrierProvidedbylowpermfoamboardinsulationInteriorfinishvapourpermeabletoallowdryingtoinsidePossibleAirBarrierLocationsVapourBarrierLocationOutsideInsideCladdingWRBLowPermFoamBoardJointsTapedSheathingInteriorFinishDrainage/VentilationPlaneRainScreenCladdingspacedoutfromWRBtypicallyby12mmto19mm(1/2”

to¾”)andlargerinthecaseofbrickveneer.Crosscavityflashingsprovidedatallwallopenings,penetrationsandatfloorlines.ProvidescapillarybreakbetweenbackofcladdingandWRBProvidesadrainageplanetoredirectwaterbackoutofthewallthathaspenetratedthecladding.IfventedtopandbottomcanenhancedryingofthewallassemblyIncombinationwithWRBwillresistreversevapourdrive.WRBshingleddownfaceofsheathingoverlappingflashingsbelowCapillarybreakCrosscavityflashingFloorlinecrosscavityflashingRainScreenConstructionBreatherweatherresistantbarrier(WRB).Typicallyusedincoldandmixedclimates.HousewrapBuildingpaperAppliedhorizontallyfrombottomtotoptoallowupperlayertolapoverlowerlayer(shingle).MustalsoshingleoverallflashingstoensuredrainageWRBstapledtosheathingandhousewraptypicallytapedatjointsBuildingpaperappliedtoprovidedoublethicknessoverentirewall.

Ifouterlayerbecomessaturatedinnerlayeractsasaseparator.30minutebuildingpaperHeadflashingwithenddamHousewrapRainScreenConstructionWaterproofWRBcanbeusedinanyclimatedependingonthelocationoftheinsulation.WillalsoactasavapourbarriersomustbekeptabovethedewpointofthesurroundingairPeelandstickSBSLiquidappliedelastomericmembraneIncoldclimatemustalwaysbeinsulatedontheoutsideInmixedclimatelocatedinthecentreofthewallInhothumidclimateappliedtotheexteriorofaninsulatedwallPeelandstickWRB

overstructuralsheathingWRBInsulationDrainageplaneColdclimatewaterproofWRBapplicationRainScreenConstructionCavityconstruction12mm(1/2”)thickpressuretreatedplywoodstripsappliedverticallyoverWRBat300mmto400mm(12“to16”)spacing19mmx38mm(1x2)or19mmx89mm

(1x4)pressuretreatedverticalfiringat300mmto400mm(12“to16”)FastenedwithhotdippedgalvanizednailsorstainlesssteelnailsVerticalstrappinghasgapoverrimjoistareatoaccountforframingshrinkageRainScreenConstructionCavityconstructionCedarShinglesOpenplasticmesh“cedarbreather” providesventilationanddrainageplane.AlternatehorizontalandverticalstrappingRainScreen

ConstructionWindowinstallationsequencingRoughopeningSlopedorsteppedsillnailedinplaceandallcornersairsealedSilllinedwithbuildingpapercarryupjamJamblinedwithbuildingpaper1234RainScreenConstructionLineheadwithbuildingpaperPlacepeelandstickonsillPlacepeelandstick200mm(8”)upjamSealcornerwithdartofpeelandstickorpreformedcornerpiece5678RainScreen

ConstructionWindowinstalledandanchoredtoroughopening.Windowframeairsealedtoroughopeningwithsealantandbackerrodorfoam.Providefordrainageatbaseofwindow.HeadflashingwithenddamsinstalledoverwindowandWRBcarriedupsideofwindowframeWRBappliedoverheadflashingandinsectscreenstapledinplace.Vertical12mmto19mm(1/2”to¾”)thickstrappinginstalledoverWRBandcladdinginstalledonstrapping.9101112RainScreenConstructionExteriorsupplyorexhausthoodTightfittingholecutinsheathingWRBstapledtosheathingandcutoutaroundopeningBackerboardwithtightfittingholenailedinlineandflushtoinsidefaceofstudsEPDMsheetwithundersizedholestapledtosheathingoverWRB.Hoodwithtailpipeturnedupandtapedwithaluminum

foiltape1234RainScreenConstructionHoodpushedthroughEPDMgasketandanchoredtobackerboardUpperlayerofWRBinstalledandstapledtosheathingVerticalpreservativetreatedstrappingnailedtosheathingandstud.Claddingappliedtostrapping5678ContinuousairbarrierpreventscondensationVentingofspaceaboveinsulationallowsdryingVentareaequal1/300ofinsulatedceilingarea.Minimumclearanceaboveinsulationforventilation38mm(11/2”)Coverceilingjoistswithinsulation

topreventthermalbridgingRaisedheeltrussormodifiedrafterframingtoallowfulldepthinsulation

toexteriorwall.Iceandwatershieldatbaseofroof

toprotectfromwaterentrydueto

icedammingSoffitventIceandwatershieldAtticRoofAssemblies

forColdClimatesCathedralRoofAssembliesforColdClimatesInsulationplacedbetweentheraftersContinuousairbarrierpreventscondensation76mm(3”)ofventingaboveinsulationApproximately50%ofventingat

thesoffitand50%atthepeak.FlatRoofAssemblies

forColdClimatesInsulationbeneathroofsheathingContinuousairbarrierVentingofspaceaboveinsulationrequiredtoallowdrying1/150ofinsulatedceilingareainventsequallydistributedSlopeminimumof1in6toensurenostandingwaterInsulationoverroofsheathingReducesthermalbridgingEliminatesneedforcavityventilationFoamcanbeslopedtosimplifystructureFlatRoofAssembliesforColdClimatesInvertedroofFoamboardinsulationplacedondrainagematonroofingmembrane.Insulationhelddownbyrockorconcretepaverballast.Protectstheroofingmembrane

fromsunlightandfreezethaw

cyclesextendinglifeEliminatestheneedforroof

cavityventilationAtticRoofAssembliesforMixedClimatesContinuousairbarrierrequiredtopreventcondensationinwinter

andsummerVentingofspaceaboveinsulationrequiredtoallowdrying

ofconstructionmoistureLowpermeancefoamboardinsulation

placedonundersideofrooftrussesto

preventcoolinginthesummer

causingcondensation.Raisedheeltrussusedto

carryfulldepthinsulation

toexteriorwall.CathedralRoofAssembliesfor

MixedClimatesInsulationplacedbetweentheraftersContinuousairbarriercondensationsummerandwinterLowpermeancefoamboardinsulationplacedonundersideofrafterssummercondensation.Ventingaboveinsulationtoallowfor

dryingfromconstructionmoistureApproximately50%of

ventingatthesoffitand

50%atthepeak.FlatRoofAssembliesforMixedClimatesInsulationbeneathroofsheathingContinuousairbarriertopreventcondensationsummer

andwinterLowpermeancefoamboardinsulationpreventscondensationinthesummerVentingofspaceaboveinsulation

requiredtoallowdryingof

constructionmoistureVent

areaequal1/150ofinsulated

ceilingareawithvents

equallydistributedSlopeminimumof1in6to

ensurenostandingwaterFlatRoofAssemblies

forMixedClimatesInsulationoverroofsheathingRoofsheathingformsairbarrierFoaminsulationeliminatesthermalbridgingEliminatesneedforcavityventilationFoamcanbeslopedtosimplifystructureInvertedroofFoamboardinsulationplacedondrainagematonroofingmembrane..ProtectstheroofingmembranefromsunlightandfreezethawcyclesextendinglifeEliminatestheneedforroofcavityventilationAtticRoofAssembliesforHotHumidClimatesAtticspacenotventedtoexteriorandspaceconditionedLowpermeancefoamboardandroofsheathingformingair/vapourbarrier.Exteriorlowpermeancefoamboardinsulatedwallsheathingcarriedupandairsealedtoundersideofroofsheathing.CathedralRoofAssembly

forHotHumidClimatesLowpermeancefoamboardandroofsheathingformingair/vapourbarrier.Exteriorlowpermeance

foamboardinsulatedwallsheathingcarriedup

andairsealedto

undersideof

roofsheathing.FlatRoofAssemblies

forHotHumidClimatesInsulationoverroofsheathingRoofsheathingformsairbarrierFoaminsulationeliminatesthermalbridgingEliminatesneedforcavityventilationFoamcanbeslopedtosimplifystructureInvertedroofFoamboardinsulationplacedondrainagematonroofingmembrane.ProtectstheroofingmembranefromsunlightandfreezethawcyclesextendinglifeEliminatestheneedforroofcavityventilationRadiantBarrierReducedradiantheattransferRadiantheattransferRadiantBarriersRadiantbarrierisashinysurface,usuallyaluminumfoil,thatisapooremitter

ofheat.WhenincorporatedinaroofassemblyandexposedtoanopenspacecanreducetheradianttransferofheatfromtheundersideoftheroofsheathingtotheceilingbelowTypicallyinstalledontheundersideofroofsheathingfacingdown.RadiantBarriersKraftpaperbackedaluminumfoilstapledtotheundersideoftheroofsheathingRoofsheathingwithaluminumfoilbondedtotheundersideKraftpaperbackedaluminumfoilstapledtotheundersideoftheraftersChoppedaluminizedmylarsprayedovertopofinsulationPossiblelocationsforradiantbarriersRoofingMaterialsAwiderangeofroofingmaterialsareusedwithwoodframeconstructionincludingAsphaltshinglesMetalroofingRolledroofingCedarshinglesCedarshakesClaytilesConcretetilesRoofconstructionmayrequiremodificationifheavierroofingmaterialssuchasconcretetileorclaytileareused.Roofsheathingandunderlayischosentosuitroofing.RoofingMaterialsAsphaltshinglesBitumenwithfiberglassreinforcingandmineralcoatingMostwidelyusedroofingAvailableinrangeofcolours15to20yearlifeNaileddirectlytosheathingForhighwindlocationsinterlockingshinglesareusedIncoldclimatesrainandiceshieldusedatbaseofroofRoofingMaterialsCedarshinglesHavebeenusedsuccessfully

formanyyearsinCanadaShinglesaretapersawnwithsmoothfaceShouldonlybeusedonroofswithslopeof1:3orgreaterCanbeappliedoverskipsheathingorplywoodpanelsheathingRequireswat