CombustibleComponentsinExteriorWalls

y BarryThorson,P.Eng.,C.P.,FECy B.R.ThorsonConsultingLtdy CertifiedProfessional since1981y Chair APEGBCBuildingCodesCommittee19992005y CoChair BuildingPolicyAdvisoryCommittee20032009y BCBCInterpretationCommittee 19992011

CombustibleComponentsinExteriorWallsy CurrentRequirements 3.1.5.5.,3.1.5.12.,3.2.3.8.y HistoryofCodeDevelopmenty BCBuildingCodeInterpretationCommittee 980012y AppealBoardRuling BCAB#1682yWhatNext?

CurrentRequirementsy 3.1.5.5. tolimitflamespreaduptheverticalexteriorsurfaceofabuildingfromafirewithinthebuildingwhichblowsouttheexteriorwindowopeningsy 3.1.5.12. toprotecttheinteriorofabuildingfromafirehazardcausedbycombustibleinsulation,includingfoamedplasticinsulationy 3.2.3.8. toprotecttheexteriorbuildingfacetolimitthespreadoffirefromaninsidefiretoanadjacentbuilding,andtolimitthepotentialforfirespreadfromanoutsidefirefromanadjacentbuilding

BrickVeneer NotTested

TestedAssembly

Article3.1.5.5.y OnlyappliestobuildingsthatarerequiredtobenoncombustibleconstructionasdeterminedbySubsection3.2.2.y Onlyappliestononloadbearingexteriorwallsy Appliestounsprinkleredbuildingsnotmorethan3storeysinbuildingheighty Appliestosprinkleredbuildingsofanyheighty CannotbeusedwhenspatialseparationrequirementsofSubsection3.2.3.restricttheareaofunprotectedopeningstolessthan10%

Article3.1.5.5.Whatdoesitsay?y IfArticle3.1.5.5.isreadinisolationasastandalonerequirement,hereiswhatitsays:y Ifanexteriornonloadbearingwallinabuildingthatisrequiredtobenoncombustibleconstructioncontainsanycombustiblecomponentslocatedanywherewithinthewallassembly thenthewallmustbetestedtoCAN/ULCS134(fullscalefiretest)

yWOW!!!!!

Article3.1.5.1.WhatisNoncombustible?y DefinedinArticle1.1.4.2.ofDivisionAasmeetingtheacceptancecriteriaofCAN4S114 DeterminationofNonCombustibilityinBuildingMaterialsy AsperSentence3.1.5.1.(2)othermaterialsarepermittedtobeusedinanoncombustiblebuildingwhentestedinaccordancewithULCS135andmeetsvariouscriterianotethesematerialsarecombustibley AsperSentence3.1.5.11.(1)gypsumboardcanbeusedinanoncombustiblebuildingwhenpaperlayerisnotmorethan1mmthickandFSR

CAN4S114WhatisNoncombustible?y 3samplesareputinasmallfurnaceat750degreesCfor15minutesy Thematerialmustnotburnafter30secondsy Thematerialmustnotlosemorethan20%ofitsmassy Thematerialmustnotexceedatemperatureriseofmorethat36degreesChigherthanthemeantemperatureofthefurnace

Article3.1.5.5.Whatcouldthismean?y Article3.1.5.5.doesnotexplicitlyexempttheusualcombustiblecomponentsthatarelistedinArticle3.1.5.2.orSentences3.1.5.1.(2)and3.1.5.11.(1)y Paint,masticsandcaulking,includingfoamedplasticairsealants,adhesives,vapourbarriers,sheathingpapers

y If3.1.5.5.isreadinisolation Exteriornonloadingbearingwallsthatcontain6milpolyvapourbarrier,orpeel&stickmembranes,orgypsumboard,orfiberglassinsulationwouldhavetobetestedtoCAN/ULCS134

OtherCombustibleMaterialsPermittedinNoncombustibleBuildingsy 3.1.5.2. Minorcombustiblecomponentsy 3.1.5.6. Nailingelementsy 3.1.5.10. Combustibleinteriorfinishesy 3.1.5.11. Gypsumboardy 3.1.5.15. Combustibleductsy 3.1.5.16. Combustiblepipingy 3.1.5.18. Combustiblewiringy 3.1.5.21. DecorativeWoodCladding

Article3.1.5.5.Historyy Article3.1.5.5.wasoriginallyintroducedinthe1990NBCCentitledCombustibleCladdingy ItpermittedtheuseofcombustiblecladdingonnonloadbearingexteriorwallsinnoncombustiblebuildingswhentestedtoCAN/ULCS134y ThewordingofArticle3.1.5.5.wasamendedinthe1995NBCCtoreadCombustibleComponentsforExteriorWallsy TheAppendixNoteA3.1.5.5.inthe1995NBCCwasstillentitledCombustibleCladding

Article3.1.5.5.Historyy TheoriginalintentofArticle3.1.5.5.wastopermitcombustiblecladding,includingEIFS,onnonloadbearingexteriorwallsinnoncombustiblebuildingsifthecladdingsystemistestedtoCAN/ULCS134y Thechangeinwordinginthe1995NBCCwasnotincludedinthelistofproposedchangestothe1990NBCCy Thischangeofwordinghascausedagreatdealofaggravationsince1995

Article3.1.5.5.LoadBearingWallsy Article3.1.5.5.doesnotapplytoloadbearingwallsy TheuseofcombustibleinsulationinexteriorloadbearingwallsisregulatedbySentence3.1.5.12.(3) i.e.athermalbarrierisrequiredontheinsidefacey Theuseoffoamedplasticinsulationintheexteriorwallofanybuildingmorethan3storeysinbuildingheightisregulatedbyArticle3.2.3.8. theoutsidefaceisprotectedwith25mmonconcreteormasonry,oranothernoncombustiblematerialthatmeetscertaincriteriawhentestedtoCAN/ULCS101.

Article3.1.5.5.SpatialSeparationWallsyWhenSubsection3.2.3.restrictstheareaofunprotectedopeningstolessthan10%,theexteriorwallisrequiredtobenoncombustibleconstructionwithnoncombustiblecladding.y Article3.1.5.5.cannotbeusedforsuchwalls.y Theoriginalintentwastoprecludetheuseofanycombustiblecladdingonwallsclosetothepropertyline,evenwhensuchwallscomplywithCAN/ULCS134.

Article3.1.5.5.OntarioBuildingCodey TheOntarioBuildingCodeamendedthe2005NBCCtosaythatifanexteriorwallcomplieswithArticle3.2.3.8.,thenitisdeemedtoalsocomplywithArticle3.1.5.5.y AlthoughmanyAHJsagreewiththisconcept,theNBCCandBCBCdonotexplicitlystatethis.

Sentence3.1.5.12.(3)Protectstheinsidefaceonlyy Firesoriginatinginsidethebuildingy AppliestobothcombustibleinsulationandfoamedplasticinsulationwithFSR>25and

Article3.2.3.8.SpatialSeparationsy Protectionofexteriorbuildingfaceonlyy DoesnotaddressprotectionoftheinteriorfaceyOnlyapplieswhentheexteriorwallcontainsfoamedplasticinsulationy Tolimitfirespreadfromafirethatoriginatesinsidethebuildingtoaneighbouringbuildingonanadjacentpropertyy Tolimitfirespreadfromafirethatoriginatesinaneighbouringbuildingtotheexteriorbuildingfaceofthebuildingonourproperty

Article3.2.3.8.ProtectionofExteriorBuildingFacey Onlyappliestobuildings>3storeysy 25mmconcreteormasonry,ory NoncombustiblematerialthatmeetscertaincriteriawhentestedtoCAN/ULCS101y Ifanexteriorwallmeets3.1.5.5.thenitisdeemedtoalsomeet3.2.3.8.

History3.1.5.5. 3.1.5.12. 3.2.3.8.

1977NBCC no yes no1980NBCC no yes yes1985NBCC no yes yes

1990NBCC yes yes yescombustiblecladding

1995NBCC yes yes yescombustiblecomponents

2005NBCC yes yes yescombustiblecomponents

History3.1.5.5. 3.1.5.12. 3.2.3.8.

1985BCBC no yes yes

1992BCBC yes yes yescombustiblecladding

1998BCBC yes yes yescombustiblecomponents

2006BCBC yes yes yescombustiblecomponents

BCBCInterpretationCommittee980012y Question DoesArticle3.1.5.5.applytotheentireexteriornonloadbearingwallassembly?y Answer yes theentirewallassemblymustbetestedbecausetheperformanceofsomeexteriorcladdingsystemsmaydependonthewallassemblytowhichtheyareattached

BCBCInterpretationCommittee980012y Question IftheexteriornonloadbearingwallassemblycontainscombustiblecomponentsthatareotherwisepermittedbySubsection3.1.5.,isthewallassemblyrequiredtocomplywithArticle3.1.5.5.y Answer No theCommitteeconsideredthatArticle3.1.5.5.wasoneofmanyoptionsavailabletodesignerstousecombustiblecomponentsinexteriorwalls.y Problem thispreviousinterpretationisbeingreviewedbytheCommitteeinresponsetoBCAB#1682since3.1.5.5.and3.1.5.12.dealwithdifferentfirescenarios.

BuildingCodeAppealBoardBCAB#1682 ExteriorWally SheetsteelcladdingyWeatherbarrier(airgap)y Foamedplasticinsulation(25

BCAB#1682AppellantsPositiony ThewallassemblycomplieswithSentence3.1.5.12.(3)y Since3.1.5.12.(3)permitstheuseofcombustibleinsulation,includingfoamedplasticinsulation,thereisnoneedtoalsocomplywithArticle3.1.5.5.y ThescopeofArticle3.1.5.5.islimitedtocombustiblecladdingasindicatedbythetitleofAppendixNoteA3.1.5.5.y ThisinterpretationisconsistentwithBCIC980012

BCAB#1682BuildingOfficialsPositiony Article3.1.5.5.doesnotincludeanyexemptionsforArticles3.1.5.2.(minorcombustiblecontent),3.1.5.11.(gypsumboard)or3.1.5.12.(combustibleinsulation)y Article3.1.5.5.isastandalonerequirementthatmustbemetinadditiontoalloftheotherprovisionsofSubsection3.1.5.

BCAB#1682RulingoftheBoardy BothArticles3.1.5.5.and3.1.5.12.applytotheuseofcombustibleinsulationinexteriornonloadbearingwallsinabuildingthatisrequiredtobenoncombustibleconstructiony SinceArticle3.1.5.12.onlyprovidesthermalprotectionontheinsideface,itdoesnotaddressthespreadoffireontheexteriorfaceofthebuilding

BrickVeneer NotTested

TestedAssembly

WhatNext?yWeneedacodechangetotheNBCC,BCBCandVBBLy Article3.1.5.5.shouldgobacktotheoriginalintentindealingwithcombustiblecladdingratherthancombustiblecomponentswithintheentirewallassemblyy IfyoucomplywithArticle3.2.3.8.,youneednotcomplywithArticle3.1.5.5.y Combustiblematerialsasdescribedin3.1.5.1.(2),3.1.5.2.,3.1.5.6.,3.1.5.10.,3.1.5.11.,3.1.5.16,3.1.5.18.and3.1.5.21.shouldbepermittedinexteriorwalls

Questions?

Combustible Components in Exterior WallsCombustible Components in Exterior WallsCurrent RequirementsBrick Veneer Not TestedTested AssemblyArticle 3.1.5.5.Article 3.1.5.5.What does it say?Article 3.1.5.1.What is Non-combustible?CAN4-S114What is Non-combustible?Article 3.1.5.5. What could this mean?Other Combustible MaterialsPermitted in Noncombustible BuildingsArticle 3.1.5.5.HistoryArticle 3.1.5.5.HistoryArticle 3.1.5.5.Load Bearing WallsArticle 3.1.5.5.Spatial Separation WallsArticle 3.1.5.5.Ontario Building CodeSentence 3.1.5.12.(3)Protects the inside face onlyArticle 3.2.3.8.Spatial SeparationsArticle 3.2.3.8.Protection of Exterior Building FaceHistoryHistoryBCBC Interpretation Committee98-0012BCBC Interpretation Committee98-0012Building Code Appeal BoardBCAB #1682 Exterior WallBCAB #1682Appellants PositionBCAB #1682Building Officials PositionBCAB #1682Ruling of the BoardBrick Veneer Not TestedTested AssemblyWhat Next?Questions?