15LL11 Practical Code Compliant Detailing for Mid-Rise ... · 2. Examine a variety of...

Practical,Code-CompliantDetailingforMid-RiseWoodStructuresDetailingConsiderationsforMidRiseWoodFrameBuildings

“TheWoodProductsCouncil”isaRegisteredProviderwithTheAmericanInstituteofArchitectsContinuingEducationSystems(AIA/CES),Provider#G516.

Credit(s)earnedoncompletionofthiscoursewillbereportedtoAIACESforAIAmembers.CertificatesofCompletionforbothAIAmembersandnon-AIAmembersareavailableuponrequest.

ThiscourseisregisteredwithAIACESforcontinuingprofessionaleducation.Assuch,itdoesnotincludecontentthatmaybedeemedorconstruedtobeanapprovalorendorsementbytheAIAofanymaterialofconstructionoranymethodormannerofhandling,using,distributing,ordealinginanymaterialorproduct.________________________________Questionsrelatedtospecificmaterials,methods,andserviceswillbeaddressedattheconclusionofthispresentation.

CourseDescription

Withanincreaseinmid-risewood-framebuildings,moredesignersareseekinginformationoncode-compliantandconstructibledetailing.Manyareunsureofthecode’srequirementsfordetails,specificallyattheintersectionofratedassembliesandwherestructureandfireprotectionmeet.Thispresentationwillfocusoncommondetailingissuesandareasofmisunderstanding—includingfire-resistanceratingcontinuity,allowableusesofwoodframinginshaftandfirewalls,andfiresafetyprinciplesassociatedwiththeintersectionoftworatedassemblies.Mid-risewood-frameopportunitiesandcode-specifiedbuildingsizeswillalsobereviewed,followedbydiscussionofdetailingcoderequirements,codecompliance,andrationaleforapprovalwithanemphasisonconstructabilityandpracticality.

LearningObjectives

1. Discussallowableconstructiontypes,occupancies,andbuildingheightsandareasforwood-framemid-riseconstructionpertheInternationalBuildingCode.

2. Examineavarietyoffloor-to-exteriorwalldetailsforuseinwood-frame,TypeIIIconstructionanddiscusscodecompliancepathsandapprovalrationaleforeach.

3. Discusscode-permittedshaftwallandfirewallconstructionmaterialsandfire-resistancerequirements,andreviewcommondetailsforeach.

4. Considercodeprovisionsforcorridorandbalconyfire-resistanceprotection,andidentifydetailsthataccommodatetheserequirementswhilemaximizingwooduse.

Outline

• Mid-RiseConstructionTypes&LifeSafetyReview• StructuralDesign&DetailingConsiderations• ShrinkageConsiderations&Detailing• AcousticRequirements&Detailing• FireResistiveRequirementsandDetailing

Mid-RiseConstructionTypes

Materials ProtectedElements

LessProtectedElements

UnprotectedElements

Non-Combustible IA,IIA IB IIB

Combustible - - -

Mixed Systems IIIA IIIB -

HeavyTimber - IV -

AnyMaterials VA - VB

ICCBuildingValuationData

80

90

100

110

120

130

140

150

160

IA IB IIA IIB IIIA IIIB VA VB

$pe

rSqu

areF

oot

IBCConstruction Type

InternationalCodeCouncil,August2015DataR-2Occupancy

PrimaryStructuralWoodFramingAllowed

IBCBuildingSizeLimits

Construction TypeAllowableLimit

IIIA IIIB VA VB

Stories 4 4 3 2Height(ft) 65 55 50 40BuildingArea/Story(ft2) 24k 16k 12k 7kTotalBuildingArea*(ft2) 72k 48k 36k 14k

IBC2012Table503TabularValues

Residential(R1,R2,andR4)Occupancies

*Assumingmaxstoriesbuilt

IBCBuildingSizeLimits

WithNFPA13Sprinklers:IBCgivesanallowableHeightsandAreaIncrease

IIIATabularHeightLimits IncreasedLimits

NFPA13

IBCBuildingSizeLimitswithSprinkler

TypeIIIAConstructionAllowableLimit

Table503

Stories 4Height(ft) 65BuildingArea/Story(ft2) 24kTotalBuildingArea*(ft2) 72k

Residential(R1,R2,andR4)Occupancies

*AssumingmaxstoriesbuiltperIBC506.4

503

NPFA13

58524k72k

504.2IBC2012Section

NPFA13

58572k216k506.3

Frontage**

58590k270k506.2

**Maximumfrontageincreasepossible

StellaApartmentsLocation:MarinaDelRay,CA244Apts.,650Ksf total(2bldgs)TypeIIIAandVAconstructionPanelizedwoodframingsaved1-2monthsconstructiontimeand$200,000

CaseStudy:StellaApartments

Architect:DesignARC.LosAngeles,CAPhotos:LawrenceAnderson,www.lawrenceanderson.net

Outline


Structural• Directbearing/noadd’l

hardware• Mayrequireloadtransfer

blockingforconcentratedloadsfromabove

• Wallsoleplateandfloorsheathingcrushingmayneedtobeconsidered

Constructability• Framingcanbecompletedbefore

drywallandinsulationareinstalled

• Commonlengthstuds

PlatformFraming

Semi-balloonFraming

Structural• Additionalhardware/nodirect

bearing• Noloadtransferblockingreq’dRatedAssemblies• Mayaccommodatecontinuity

inexteriorwallsinTypeIIIconstruction

Constructability• Framingcanbecompleted

beforedrywallandinsulationareinstalled

• Customlengthstuds• Canhelpminimizebuilding

shrinkage

ShearWallFramingConsiderations

TypicalFloorPlanShearWallLayoutIndicateswoodsheathedshearwall


• Typicalfloorplanresultsinshortersolidwallsections,offsetwalls,needformorecollectors,struts

• Shorterwalls=higherconcentratedloads• Higherconcentratedloads=tighternailing,largerholddowns&

endposts,possiblydoublesidedsheathing• Coderequirementsforwallheighttowidthratiosmustbemet• Accumulatedloadsfurtherconcentrateforcesinlowerlevel

walls


• Shearwallcomponentscanaffectotherbuildingfeatures

• EndPosts:Morewoodinwall=lessinsulation

• Sheathingoninteriorwallsaffectwallfinishes,acoustics

• Holddowns,endposts,blockingcanaffectin-wallutilities

• OpeningsinwallsforMEPcanaffectshearwallstrength

ShearWallConfigurationOptions

SolidorSegmentedWalls

PerforatedWallsForceTransferAround

OpeningsWalls

ShearWallHoldDownOptions

StandardHoldDownInstallation StrapHoldDown

Installation

……

……

……

…

Continuous Rod - Automatic Tensioning Systems

DiaphragmConsiderations

TypicalFloorPlanDiaphragmLayout

Open

DiaphragmConsiderations

• Typicalfloorplanresultsindiaphragmoffsets,re-entrantcorners,discontinuities,openings

• Diaphragmopenings,discontinuities=higherconcentrated,localizedloads

• Higherconcentratedloads=tighternailing,largerchord&strutloads,mayrequireblockeddiaphragm

• Coderequirementsfordiaphragmlengthtowidthratiosmustbemet

ShearWalltoPodiumSlabInterface

• AmplificationofseismicforcesisrequiredforelementssupportingdiscontinuouswallsperASCE7-1012.3.3.3

• Overstrength factorof3(maybereducedto2.5perfootnotegofTable12.2-1)isrequired

• AttachmenttoconcreteslabmustalsoconformtoACI318AppendixD

• TypicallywillbetransitioningfromASDforwooddesigntoLRFDforconcretedesign

• Holddownattachmentstoconcreteoptions:embeddednutsorplates,sleevesthroughslab,weldedstuds&reinforcing

PTSolePlatevs FRTContinuity

IntypeIIIconstructionwithFRTstuds,whathappenswherethesoleplateisincontactwithconcrete?

• FRTWisrequired• PTwoodisrequiredFRTcontainsabout10xboratecompoundfoundinPT(borateiswatersoluble)Canspecifyaproducttestedtodoboth

Outline

• Mid-RiseConstructionTypes&LifeSafetyReview• StructuralDesign&DetailingConsiderations• ShrinkageConsiderations&Detailing• Concepts• Calculations• Recommendations

• AcousticRequirements&Detailing• FireResistiveRequirementsandDetailing

IBC2012onShrinkage2304.3.3Shrinkage.Woodwallsandbearingpartitionsshallnotsupportmorethantwofloorsandaroofunlessananalysissatisfactorytothebuildingofficialshowsthatshrinkageofthewoodframingwillnothaveadverseeffectsonthestructureoranyplumbing,electricalormechanicalsystems,orotherequipmentinstalledthereinduetoexcessiveshrinkageordifferentialmovementscausedbyshrinkage.Theanalysisshallalsoshowthattheroofdrainagesystemandtheforegoingsystemsorequipmentwillnotbeadverselyaffectedor,asanalternative,suchsystemsshallbedesignedtoaccommodatethedifferentialshrinkageormovements.

KeyFactorsInfluencingShrinkage

• Pre-constructionmoisturecontent(MC)• In-serviceequilibriummoisturecontent(EMC)• Cumulativethicknessofcross-grainwood

contributingtoshrinkage

Woodspecieshasrelativelylittleimpactsincemostspeciesusedincommercialconstructionhavesimilarshrinkageproperties.

Moisturechangescausedimensionalchangesperpendiculartograin

Growingtreeisfilledwithwater

Aswooddries,itshrinksperp.tograin

BasicWoodShrinkageTheory

Image:WoodHandbook,WoodasanEngineeringMaterial,USDAForestService,ForestProductsLaboratory,2010

Wider&Thicker--- NOTTaller

ShrinkageinlumberexpectedACROSSthegrain.Longitudinalshrinkageisnegligible.


ZoneofMovementShrinkageoccursprimarilyinhorizontalmembers• Wallplates• Floor/rimjoists

Beawareofcumulativeshrinkage.

Pre-ConstructionMoistureContent

Mi=19%Mi=28%

MinimizeConstructionMoistureAccumulation

1. Minimizestorageofmaterialonsitewhererainandstandingwatercanincreasemoisturecontent.

2. Keepunusedframingmaterialcovered3. Inspectpre-builtwallpanelspriortoinstallationforproper

materialandqualityofmechanicalfasteners.4. “Dry-in”thestructureasquicklyaspossible.5. Immediatelyremoveanystandingwaterfromfloorframing

afterrainshowers.6. EnsurethatinstalledlumberMCisloweredto19%or

calculatedmaxMCbeforeinstallingfinishes&insulation

In-serviceAverageEMCinJuly

34

Map courtesy of US Forest Products Laboratory

In-serviceAverageEMCinJanuary

35

Map courtesy of US Forest Products Laboratory

ComprehensiveShrinkageEstimation

ForachangeinMCbetween 6%and14%theshrinkageformulais:

( )[ ]iFTi MMCDS −=

CalculatingShrinkage

S=shrinkage(ininches)

Di =initialdimension(ininches)

CT /CR=dimensionchangecoefficient,tangential/radialdirection

CT =0.00319forDouglasFir-LarchCT =0.00323forHem-FirCT =0.00263forSpruce-Pine-FirCT =0.00263forSouthernPine

MF =finalmoisturecontent(percent)

Mi =initialmoisturecontent(percent)

ComprehensiveShrinkageEstimation

ForMCoutside therangeof6to14%:

( )

iT

iFi

MS

MMDS

+−

−=

30)100(30

CalculatingShrinkage

S=shrinkage(ininches)

Di =initialdimension(ininches)

ST /SR=tangential/radialshrinkage(%)fromgreentoovendry

MF =finalmoisturecontent(percent)

Mi =initialmoisturecontent(percent)

CalculatingShrinkage– Resources

WoodHandbook:www.fpl.fs.fed.us• Chapter13– CT,CR• Chapter4– ST,SR

ExampleShrinkageCalculation

Assume:S-DrylumberFind:ShrinkageinPlates&FloorJoist

ShrinkageZone:2x4UpperPlate2x12FloorJoist4x4LowerPlate16.25”Total

QuickShrinkageEstimation:

AgainassumingtheinitialMC(Mi)is19percentandthefinalMC(MF)is12percent

Ourapproximatedshrinkageis:

ForDougFirLarch:

ForS-P-ForSouthernPine:

S =CDi MF −Mi( ) = 0.00319×16.25 12−19( ) = −0.36inch


S =CDi MF −Mi( ) = 0.00263×16.25 12−19( ) = −0.3inch

MinimizingShrinkage

Semi-balloonframing• incorporatesfloorframing

hangingfromtopplates• Eliminatestangential

shrinkageinzoneofmovement

• Floorframingdoesn’tcontributetooverallbuildingshrinkage

Non-standardstudlengthsandincreasedhardwarerequirementsarearesult.

ExampleShrinkageCalculationAssume:S-DrylumberFind:Shrinkagein2x4UpperPlate&4x4LowerPlate

ShrinkageZone:2x4UpperPlate4x4LowerPlate5”Total

QuickShrinkageEstimation:

AgainassumingtheinitialMC(Mi)is19percentandthefinalMC(MF)is12percent

Ourapproximatedshrinkageis:ForDougFirLarch:

ForSouthernPine:

S =CDi MF −Mi( ) = 0.00319×5 12−19( ) = −0.11inch


S =CDi MF −Mi( ) = 0.00263×5 12−19( ) = −0.09inch

DifferentialMovement

Movementbetweenwoodframeelementsandothermaterialsthat…

• donotshrinkatall

• shrinkmuchless

• expand

Shrinkage&FinishConsiderations

Largeexpansesofinteriorandexteriordrywall,panelingandsidingneedtobelookedatspecifically.

Employexpansionjointandslip-typedetailing.

Attentiontointeractionofstructural(load-bearing)andnon-structuralelementsisnecessary

Shrinkage&MEPConsiderations

FullycompresswallframingbycompletingalldeadloadpotentialPRIORtomechanicalinstallations.

Avoidrigidverticalpipinginmechanicalandplumbingsystems.Flexiblemembersallowforshrinkagebetweenfloors.

MEPConsiderations

Verticalventstacksshouldbeinstalledaftercompletionofframing.

Ventstacksrequirespecialattentionandmustbedesignedtoallowforverticalmovementduetoshrinkagebetweenfloors.

MEPJointOptions

AvarietyofexpansionorslipjointconnectorsareavailablewhichaddressthisissueandallowverticalmovementinMEPitemsduetobuildingshrinkageand/orthermalchangewithoutcausingdamagetothem

BrickFaçade:Solution1- PlainUnreinforcedBrick-h>30’

Allowsforverticalshrinkageofwoodframing

VeneermustbedesignedperACI530section2.2asplainunreinforcedmasonry

Anchors/tiestobespacedamaximumof32”o.c.horiz.And18”o.c.vert.(exceptseismic)

Requiressteellintelatopenings

Jointsmustallowforalldifferentialmovement(lateraldriftandvertical shrinkageofwoodFramingEtc.).WeightofbrickmustnotbesupportedbywoodFraming

Woodbackerstuds

Brickgoesintoflexurewhenwallstudsdeflect

DesignmustbeinstrictconformancewithACI530section6.2.1-Alt.designmethod(engineered)

Designtosection2.2(ASD)or3.2.2(strength)unreinforcedmasonry

Brickveneermustbeselfsupportingandnotsupportedoffofthewoodframing

BrickFaçade:Solution2- StructuralReinforcedBrick

BrickunitsaresimilartoCMU’swhereverticalandhorizontalreinforcingcanbeinstalled• Veneerspansfloortofloor

withouttransferringloadstowalls.

• Loadsaredumpeddirectlyintofloordiaphragms

• Steellintelsoveropeningsarenotrequired

• Intermediateanchors/tiesarenotrequired

• Wallspansvert.&horiz.Betweenspacedanchors

Reinf.horizontalbondbeamorlintelunitsoveropenings

Spacedanchorsmustallowforalldifferentialmovement(lateraldrift,vertical shrinkageofwoodFraming,etc.).WeightofbrickmustnotbesupportedbywoodFraming

Woodbackerstuds

Reinforcementreducesexpansionandcracking

Anchors/tiesaretieddirectly intofloordiaphragms

Veneeractsascompleteunit,notasindividualSegments.Supportsselfweightplusout-of-planeloads

#3or#4rebar (typ.)

Heavieranchorsarenotaspronetofiredamage

4”nom.orgreater

FaçadeConsiderations- Resourceswww.woodworks.org

FaçadeConsiderations- Resources

BrickIndustryAssociation–www.gobrick.com

DoorandWindowConsiderations

Sealantjointsizedtoallowshrinkageofwoodframeandexpansionofbrick(typically¼”to½”perfloor)


FlashingandCounterFlashingDetailedtoProvideVerticalFlashingSlipJointtoAccommodateMovement

Source:FPInnovations


Gapunderflashingallowsverticalmovement

Source:CENews,Feb2014


Source:CENews,Feb2014

ShrinkageEffectsonStructuralComponents

Strapholddownscanbucklewithtoomuchaccumulatedmovement.

Anchortypeholdownsshouldre-tightenedbeforeinstallingfinishes.

Threadedrodholdownswithshrinkagecompensatingdevicesworkwellfor4storiesandabovewithstackingunits.

Shrinkage&DeckConsiderations

WhitePaper:Multi-StoryWood-FrameShrinkageEffectsonExteriorDeckDrainage:ACaseStudybyZenoMartin,WoodDesignFocusFall2010

ShrinkageMitigatingDetailingTips

Bestpracticestomitigatedistresstofinishesarisingfromcumulativedifferentialmovement:• Beacutelyawareofthefactthattherewillbedifferentialmovement• Addressitindetailingandspecifications• Considerwheredistresswilloccur• Providedetailstorelieveoravoidit

Architects:CooperCarry&ThePrestonPartnershipPhoto:AerialPhotographyInc.

ShrinkageResources– www.wwpa.com

Outline


BuildingAcousticsOverview

Air-bornesound:• SoundTransmissionClass

(STC)Measureshoweffectivelyanassemblyisolatesair-bornesoundandreducesthelevelthatpassesfromonesidetotheother

Structure-bornesound:• ImpactInsulationClass

(IIC)Evaluateshoweffectivelyanassemblyblocksimpactsoundfrompassingthroughit

AcousticalCodeRequirements

IBCSection1207:

Min.STCof50(45iffieldtested)for:• AllWalls,Partitions,andFloor/CeilingAssemblies

whichseparateadjacentdwellingunitsoradwellingunitfromanadjacentpublicarea

Min.IICof50(45iffieldtested)for:• AllFloor/CeilingAssemblieswhichseparate

adjacentdwellingunitsoradwellingunitfromanadjacentpublicarea

AcousticalIsolationBetweenUnits

ClassDesignation Airborne SoundIsolation(STC)

FloorCeilingImpactIsolation(IIC)

EntryLevel 50 50

MarketRate 55 55

Luxury 60 60

Exterior-to-Unit

SingleFamily

LandUseCategory ExteriorDay/NightNoiseLevels(Ldn,dBA)

MultiFamily

Motel,Hotels

OutsideUse

55 60 65 70 75 80

NormallyAcceptable

Conditionally Acceptable

NormallyUnacceptable

ClearlyUnacceptable

StateofCaliforniaGeneralPlanGuidelines,1987

Retail-to-Unit

TypicalFloor-CeilingDetailAlthoughcommonbetweenrestaurantsorbarsandtheapartments above,theconfigurationshowninthisdetailmayleadtonoisecomplaints byapartmentoccupants.

RatedAssemblies

OneofManyPerformanceGoals

UniversityofWashingtonStudentHousingSeattle,WAArchitect:MahlumThisfive-building projectincludes astrategiccombination ofstaggeredanddouble studwallstominimizesoundtransmission. Photo:BenjaminBenschneider

AcousticallyRatedAssemblies

ManyavailablefreeonlineSTC&IICratedassemblycharts(USG,GP,others)

AcousticallyRatedAssemblies

AirTightandInsulated

Examplesofineffectiveandeffectiveinstallation

PhotoDr.EnergySaver

ElectricalBoxes– AvoidFlankingPaths

Walls– DoubleStud

STC63PartyWallImage:tmsoundproofing.com

Walls– StaggeredandSingleStud

Afterdoublestudconstruction,thenextbestsolutionsarestaggeredandsinglestud.

Photos:RootGraphics(l);ArchWoodProtection

AcousticalDetailing

ImprovementFactor:Sheathing

Effectofsheathing placement onacoustical performance

ImprovementFactor:Insulation

Themostcost-effectiveacousticalimprovementtoasoundinsulationsystemistheadditionofbattinsulationoranyopencellfoamsystemtothestudorjointcavity.

PhotoDreamstime

ImprovementFactor:ResilientChannels

Metalchannelsfoundinwoodframing

Acoustical‘puckisolator’walldetail(isometricview)

ImprovementFactor:ResilientChannels

Properresilientchannelandfastenerinstallationiskeytotheperformanceofthesystem

Floor-CeilingSystems

AcousticalDetailing

Effectivefloor-ceilingoptionincludes:• Gypcreteorlight-weightconcrete• Impact isolationmatt• Tongueandgroovesubfloor(gluedandscrewedtothe joist)• Joistsystem(with6inchesofbattinsulation)• Resilient channelorpucksystem(resilient system)• Twolayersof5/8-inchtype“X”gypsumboard

ImpactIsolation

Impact IsolationProgression inWood-FrameFloors/Ceilings (SectionView)

Forclarity,battinsulationinthejoistcavityisnotshown

AdditionalAcousticsBestPractices

• Avoidcreatingflankingpaths• Isolatemechanicalsystemsbetweenunits• Sealopeningsinassemblies(whereairflows,sound

flows)• Avoidaligningdoorsonoppositesidesofcommon

hallways

Doorways– AvoidFlankingPaths

Avoidaligningdoorsonoppositesidesofcommonhallways

HVAC– AvoidFlankingPaths

Isolatemechanicalsystemsbetweenunits

AdditionalConsiderations

CrescentTerminusAtlanta,GAThree-building, five-storymixed-usecomplexwithresort-style amenities

PhotoCrescentCommunities

Outline


• ExteriorWalls• FloortoWallDetailing• InteriorWalls• ShaftWalls• Corridors&Balconies

Key Differences in Fire Ratings for Construction Types

IIIA IIIB VA

Exterior (bearing) wall framing FRT FRT non-FRT

Exterior wall fire rating 2 hr 2 hr 1 hr

Interior bearing wall fire rating 1 hr 0 hr 1 hr

Interior non-bearing wall fire rating 0 hr 0 hr 0 hr

Floor assembly fire rating 1 hr 0 hr 1 hr

Fire wall rating 3 hr 3 hr 2 hr

FireResistanceRatings

IBCTables601&706.4Note:FRT=FireRetardantTreated

FirePerformanceCo

mbu

stibility FireResistance

FlameSpreadClassificaiton

Fire-ResistanceRatedWallAssemblies

FireConfinement StructuralPerformance

Fire-ResistanceRating:Theperiodoftimeabuildingelement,componentorassemblymaintainstheabilitytoconfineafire,continuestoperformagivenstructuralfunction,orboth,asdeterminedbythetests,orthemethodsbasedontests,prescribedinSection703.Tested underastandardizedtestfireexposureforagivendurationto:

1. Preventthepassage offlameandtemperature risefromonesidetotheother

2. Continue toprovideverticalstructuralsupportwhenexposed tofireandelevatedtemperatures

Fire-ResistanceRatedWallAssemblies

There arefive basictypesoffire-resistanceratedwallassemblies:• LightFrameBearingWalls(IBC704.4.1)• ExteriorWalls(IBC705)

• FireWallorPartyWall(IBC706)• FireBarrier(IBC707)• FirePartition(IBC708)

LightFrameBearingWalls(IBC704.4.1)

Kingstuds,jackstuds,andboundaryelementsmayhavefire-resistanceratingprovidedbymembraneinloadbearingwall

Typ.BearingWallOpeningFraming

ExteriorWalls- FSD

Basicassumptionisthatfiresbeginattheinteriorandratedwallassembliesarenotrequiredfrom theexteriorunlessclosetoanotherstructure.

Interior

Exterior

FireProtectiononInsideofBuilding

ExteriorWalls(IBC705)705.5 FireResistanceRatings:Exteriorwallsshallbefire-resistanceratedinaccordancewithTables601and602andthissection.Therequiredfire-resistanceratingofexteriorwallswithafireseparationdistanceofgreaterthan10feet(3048mm)shallberatedforexposuretofirefromtheinside.Therequiredfire-resistanceratingofexteriorwallswithafireseparationdistanceoflessthanorequalto10feet(3048mm)shallberatedforexposuretofirefrombothsides.

Interior

Exterior

X<10’

LotLine

Table 601&602

ExteriorWallFireResistance

ExteriorWall– Bearingvs.NonBearing

Nonloading-bearingexteriorwallsmayhavelowerfireresistanceratingrequirementsthanbearingwallsincertainsituations.IBCChapter2definesloadbearingwallsas:

ExteriorWallFireRatings

• Usingtheprovisionsofsection705.5andTables601and602couldresultinrequiringa1houror2hourratingontheinsidefaceofexteriorwalls,whilenoratingisrequiredontheexteriorfaceofexteriorwalls.

• Howdowespecifysuchanasymmetricassembly?

• Thisiswhereprescriptivecodemethodologybeginstobreakdown:proceduraldatadoesnotalignwithrequirements.Mostbuildingjurisdictionsunderstandthatthisisadeficiencyofthesystemandwillrecognizeonetestedassemblyfortheoutsideandasecondfortheinside.

2"HOUR EXTERIOR WALL

FRAMING AT 16" O.C.. MIN. 2 X 4

1 LAYER 5/8" FIBERGLASS MAT GYPSUM SHEATHING

STRUCTURAL WOOD PANEL(S)

WHERE REQUIRED FOR SHEAR

2"HOUR RATING PER UL DESIGN NO. U371

EXTERIOR CEMENT PLASTER, MIN. THICKNESS

3/4" TO FACE OF LATH

MIN. 3" THICK MINERAL

WOOL BATT INSULATION

2 LAYERS 5/8" TYPE 'X' GYPSUM

BOARD AT INTERIOR CONDITIONS

EXTERIOR CEMENT PLASTER OVER FIBERGLASS MAT GYPSUM

SHEATHING AT EXTERIOR CONDITIONS

ExteriorWalls- Asymmetry

Commonissueswithtestedassemblies:

• AssemblyAsymmetry-separateassembliesforeachside

ExteriorWalls– 1HRInt.0HRExt.

ChoosingFireRatedAssembliesCommontestedassemblies(ASTME119)perIBC703.2:• ULListings• GypsumCatalog• ProprietaryManufacturerTests• IndustryDocuments:suchasAWC’sDCA3

AlternateMethodsperIBC703.3• PrescriptivedesignsperIBC721.1• CalculatedFireResistanceperIBC

722• Fire-resistancedesignsdocumented

insources• Engineeringanalysisbasedona

comparison• Fire-resistancedesignscertifiedby

anapprovedagency

ExteriorWalls– StructuralStability

705.6StructuralStability:ThewallshallextendtotheheightrequiredbySection705.11andshallhavesufficientstructuralstabilitysuchthatitwillremaininplaceforthedurationoftimeindicatedbytherequiredfire-resistancerating.Whereexteriorwallshaveaminimumfireseparationdistanceofnotlessthan30feet(9144mm),interiorstructuralelementswhichbracetheexteriorwallbutwhicharenotlocatedwithintheplaneoftheexteriorwallshallhavetheminimumfire-resistanceratingrequiredinTable601forthatstructuralelement.Structuralelementswhichbracetheexteriorwallbutarelocatedoutsideoftheexteriorwallorwithintheplaneoftheexteriorwallshallhavetheminimumfire-resistanceratingrequiredinTables601and602fortheexteriorwall.

ExteriorWalls– VerticalOffsets

NolessthanSameratingaswallabove

Exteriorwall

Exteriorwall

Thereisnorequirementforanexteriorwalltoextendtothefoundationinasteppedbuilding.

Posts,beamsorwalls,thatsupportaratedexteriorwallmustbefire–resistanceratednotlessthantheratingofthesupportedwall(IBC704.1)

ExteriorWalls– AdditionofWSP

CanincludeWSPinassemblieswhichweretestedwithoutthem:

• ESR2586• AWC’sDCA4

• GypsumAssociationManual

GAFireResistanceDesignManualitem23inSection1oftheGeneralExplanatoryNotes:"Whennotspecifiedasacomponentofafire- resistanceratedwallorpartitionsystem,woodstructuralpanelsshallbepermittedtobeaddedtooneorbothsides.”

ESR2586:

ExteriorWalls– UsingFRTStuds

“Woodstudwallsmaycontainfire-retardant-treatedstudsaswellasuntreatedwoodstuds.Theuseoffire-retardant-treatedplywood(woodstructuralpanels)maybeusedinDesignsthatcontainuseofuntreatedplywoodwhenallotherspecifiedattributesareequivalenttothewoodstructuralpanelusedintheDesign.”

Outline



Key Differences in Fire Ratings for Construction Types

IIIA IIIB VA

Exterior (bearing) wall framing FRT FRT non-FRT

Exterior wall fire rating 2 hr 2 hr 1 hr

Floor assembly fire rating 1 hr 0 hr 1 hr

Fire wall rating 3 hr 3 hr 2 hr

IntersectionofAssemblies- Ratings

IBCTables601&706.4Note:FRT=FireRetardantTreated

IntersectionofTestedAssemblies2Ho

urW

all

IntersectionofTestedAssemblies

1HourFloor

IntersectionofTestedAssemblies• Manyoptionsareavailableforfireresistance

testedfloorassembliesandwallassemblies• Notestedintersectiondetailsexist• Wemustunderstandtheintent ofthecode,

providearationalethatmeetsthecode’sintent,andutilizeavailableinformationandtestingresults

2HourWall

1HourFloor

2HourWall

TypeIIIExteriorWalls– FRT

TypeIIIandIVConstruction- IBCSection602.3:Fire-retardant-treatedwoodframingcomplyingwithSection2303.2shallbepermittedwithinexteriorwallassembliesofa2-hourratingorless

WhatdoesthisFRTWrequirementinclude?• WallFraming(Studs&Plates)– Yes• WallSheathing– YesFloorsheathing?RimJoist?FloorJoists?Everythingintheplaneofthewall?Oronlywallframing?

ExteriorWalls– IntersectingFloors

SomejurisdictionsinterprettheallowanceofFRTframing inexteriorwallsoftypeIIIconstructionasnotincludingFRTwallsheathing.TheinclusionofwallsheathingisintendedintheallowanceofFRTframing.

Severalcodechangeproposalsareinplacewhichclarifythis


Pleasenotethatthefollowingdetailsareexamplesofwhatwehaveseenusedonprojectsanddonotnecessarilyrepresentdetailsthatwillbeacceptedandapplicableinalljurisdictionsandtoallprojects.

Thesedetailsarenotintendedasrecommendationsforuniversallyaccepteddetails.Localproductavailabilityandmanufacturerspecificationsshouldalsobeconsideredforeachproject.

TheArchitectofRecordandEngineerofRecordshouldverifyacceptanceofthedetailsusedontheirprojectwithallprovisionsofthebuildingcode,includinglocalamendments,withthelocalAuthorityHavingJurisdiction.


UntreatedorFRT

FRTWood

LegendFloorsheathing

FRTsheathing

Rationalefordetailapproval:• Intersectionofratedassemblies

(wall&floor)consideredsufficient

TypeIIIConstruction– 2HRWall,1HRFloorTypicalPlatformFraming

Rimjoist

Considerations:• Shrinkageof

rim,plates,joists

• Protectionofrimforfire

FloorJoistOptions:• SolidSawn• Trusses• I-Joists


UntreatedorFRT

FRTWood


FRTsheathing

Rationalefordetailapproval:• Membranesonbothsideofwallprovidefire

resistanceviatheirapprovedassembly;atfloorcavity,ceilingprovides1hour,1layerofblockingprovides2nd hr throughcharcalculations


Rimjoist

Blockingbetweenfloorjoists

Considerations:• Shrinkagein

rim,floorjoists,wallplates



UntreatedorFRT

FRTWood


FRTsheathing


resistanceviatheirapprovedassembly;atfloorcavity2layersofblockingprovide2hrprotectionthroughcharcalculations


Rimjoist

Blockingbetweenfloorjoists





UntreatedorFRT

FRTWood

Legend

FloorsheathingFRTsheathing

SolidWood/GlulamRimSection

Joisthanger

TypeIIIConstruction– 2HRWall,1HRFloorModifiedPlatformFraming


resistanceviatheirapprovedassembly;atfloorcavity4xrimprovides2hr protectionthroughcharcalculations




CalculatedFireResistanceofWood

ForExposedWoodMembers:IBC722.1ReferencesAWC’sNDSChapter16(AWC’sTR10isadesignaidtoNDSChapter16)

EquationsforCalculatingFireEndurance• Assumptions• Nominalassumedcharrate=1.5”/hr.• Usesultimatestrengthfordesigncheck

• Structurallyspanningmembers:reducedsectioncheckedforcapacityvs.demand

Source:AWC’sTR10

CHARSLOWSWITHTIME-NONLINEAR

βeff = Effectivecharrate(in/hr),adjustedforexposuretime,t

βn = Nominalcharrate(in/hr),linearcharratebasedona1-hourexposure(1.5”/hr.)

t = Exposuretime(hrs)

187.0

2.1t

neff

ββ =

ACCOUNTSFORNON-CHARREDSTRENGTHRED’N

EquationsforCalculatingFireEndurance


Floorsheathing

FloorJoistOptions• DeepI-joist• HungParallel

ChordTruss

FRTsheathing

SolidWood/Glula

mRimSection

Joisthanger

TypeIIIConstruction– 2HRWall,1HRFloorModifiedPlatformFraming

UntreatedorFRT

FRTWood

Legend

Rationalefordetailapproval:• Membranesonbothside

ofwallprovidefireresistanceviatheirapprovedassembly;atfloorcavity4xrimprovides2hr protectionthroughcharcalculations

Untreated


Floorsheathing

FRTsheathing

Joisthanger

UntreatedorFRT

FRTWood

LegendTypeIIIConstruction– 2HRWall,1HRFloor

Semi-BalloonFraming

Rationalefordetailapproval:• Intersectionofrated

assemblies(wall&floor)consideredsufficient

UntreatedFloorJoistOptions:• SolidSawn• Trusses• I-Joists

Blocking


Floorsheathing

FRTsheathing

Blocking Joisthanger

UntreatedorFRT

FRTWood

LegendTypeIIIConstruction– 2HRWall,1HRFloorSemi-BalloonFramingw/Add’l FireProtection

Rationalefordetailapproval:• Ceilingmembrane

provides1hr protection;Blockinginwallprovides2nd hr throughcharcalculations



Floorsheathing

FRTsheathing

Blocking

TopflangeJoisthanger

2xblocking UntreatedorFRT

FRTWood



provides1hr protection;Blockingbetweenjoistsprovides2nd hr throughcharcalculations



Floorsheathing

FRTsheathing

Blocking


UntreatedorFRT

FRTWood



provides1hr protection;1layerofwallmembraneprovides2nd hr



Floorsheathing

FRTsheathing

Blocking


UntreatedorFRT

FRTWood


Rationalefordetailapproval:• 1layerofwallmembrane

provides1hr protection;blockingbetweenjoistsprovides2nd hr throughcharcalculations

Blocking



Floorsheathing

FRTsheathing

TopflangeJoisthangerapprovedtospan2layersGWB

UntreatedorFRT

FRTWood


Rationalefordetailapproval:• Membranesonbothside

ofwallprovidefireresistanceviatheirapprovedassembly


OverGypsumHangers

CommonlycalledFireWallorDrywallHangers

OverGypsumHangers

TopFlangeHangers&FaceMountHangersAvailable


Point#1ofInterpretation:Continuityof2hfirerating•

•Floorsheathing

FRTsheathing

Ledger(depthvaries)

TopflangeJoisthangerBlocking

UntreatedorFRT

FRTWood

LegendTypeIIIConstruction– 2HRWall,1HRFloor

Semi-BalloonFramingw/Ledger

Rationalefordetailapproval:• Membranesonbothsideof

wallprovidefireresistanceviatheirapprovedassembly;atfloorceilingmembraneprovides1hr;blockingprovides2nd hr&maintainsFRTcontinuity

Thisdetailisoftenusedwithabalcony– ledgeristhru-bolted



•Floorsheathing

FRTsheathing

Blocking

(2)2xflatblockingUntreatedorFRT

FRTWood

Legend

TypeIIIConstruction– 2HRWall,1HRFloorPlatformFramingw/TopChordBearing

Shouldspecifytrusswebholdback(3/4”

min.)toallowgypsuminstallation


Rationalefordetailapproval:• Membraneson

bothsideofwallprovidefireresistanceviatheirapprovedassembly;atfloorcavityceilingmembraneprovides1hr;1layerofwallmembraneprovides2nd hr

Untreated


•Floorsheathing

FRTsheathing

Blocking

(2)2xflatblocking


Shouldspecifytrusswebholdback(3/4”

min.)toallowgypsuminstallation



bothsideofwallprovidefireresistanceviatheirapprovedassembly;atfloorcavityblockinginwallprovides1hr;1layerofwallmembraneprovides2nd hr

UntreatedorFRT

FRTWood

Legend

Untreated


•Floorsheathing

FRTsheathing

Blocking




bothsideofwallprovidefireresistanceviatheirapprovedassembly;atfloorcavityblockinginwallprovides1hr;1layerofwallmembraneprovides2nd hr

UntreatedorFRT

FRTWood

Legend

Untreated

Topflangetrusshanger


•

Floorsheathing

FRTsheathing

(2)2xflatblocking

ExteriorWalls– IntersectingFloorsTypeIIIConstruction– 2HRWall,1HRFloorPlatformFramingw/TopChordBearing

Shouldspecifytrusswebholdback(1-

1/2”min.)toallowgypsuminstallation

Rationalefordetailapproval:• Membranes

onbothsideofwallprovidefireresistanceviatheirapprovedassembly

UntreatedorFRT

FRTWood

Legend

Untreated


•Floorsheathing

FRTsheathing

Blocking

2xrimUntreatedorFRT

FRTWood

Legend


Shouldspecifytrusswebholdback(1-

1/2”min.)toallowgypsuminstallation



Notereducedtrussbearinglength

Untreated


Gapsbtwnendoftrussmembersandwalltoallowgypsuminstallafter

Floorsheathing

FRTsheathing

(2)2xflatblocking

ExteriorWalls– IntersectingFloorsTypeIIIConstruction– 2HRWall,1HRFloor

PlatformFramingw/TopChordBearing/Ledger

Shouldspecifytrusswebholdbackto

allowledgerinstallation (2)2xledger


bothsideofwallprovidefireresistanceviatheirapprovedassembly;attopchords,ledger&sheathingprovidecontinuity

UntreatedorFRT

FRTWood

Legend

Untreated

Sheathing

Floorsheathing

FRTsheathing


UntreatedorFRT

FRTWood

Legend

Untreated

Rationalefordetailapproval:• Intersectionof

ratedassemblies(wall&floor)consideredsufficient

2xribbon

Floorsheathing

FRTsheathing


UntreatedorFRT

FRTWood

Legend

Untreated


bothsideofwallprovidefireresistanceviatheirapprovedassembly;atfloorcavityblockinginwallprovides1hr;ceilingprovides2nd hr

Blockingbetweenfloortrusses

2xribbon

Floorsheathing

FRTsheathing




InfillWallFramingBetweenTrusses

WallGypsumExtendstoUndersideofFloorSheathingBetweenTrusses

UntreatedorFRT

FRTWood

Legend

Untreated

ExteriorWalls– Bearingvs.Non-Bearing

Non-bearingExteriorWalls

PerimeterStructuralBeams

Utilizationofstructuralbeamsin-boardordirectlyoverexteriorwallscanmakewallsnon-bearingandreducerequiredfireresistanceratingto1HRor0HR(IBCTable602)Note:Beams&Columnswillmostlikelybeconsidered“PrimaryStructuralFrame”&requireindividualencasementperIBC704

FloorFraming

PerimeterStructuralColumns

ExteriorWalls– Bearingvs.Non-Bearing

Ifframingparalleltolongexteriorwallsispossible,minimizesareaofloadbearingexteriorwalls

TypeIIIConstructionDetailExamples

Whatisbeingenforcedinjurisdictionsyouareworkingin?

Outline



InteriorFire-RatedWalls:Differences

Firewalls

• BuildingSeparation

• Openingsareprotected

• Continuousfromfoundationto/throughroof

• Structuralstability

FireBarrier

• Shafts,OccupancySeparation

• Continuousfromfloorthroughconcealedspace

FirePartition:

• DwellingUnitSeparation;Corridors

• Openingsareprotected

• Mayterminateatafireratedfloor/celiling/roofassembly

FireWalls– Ratings&Materials

IBC706.3– Firewallsshallbeofanyapprovednon-combustiblematerials.

Exception:BuildingsofTypeVconstruction

FireWalls– Ratings&Materials

OpportunityforWoodFramedFireWalls:• PermittedintypeVConstruction• FireWallsintypeVConstructionofA,B,E,Rand

severalotheroccupanciesmaybe2hourFireWallsintypeIIIandIVconstructionarerequiredtobeconstructedofnon-combustiblematerials• Opportunityforwoodframebearingwallsoneach

sideoffirewalltomeetstructuralstabilityrequirements

FireWalls– StructuralStability

706.2StructuralStability:Firewallsshallhavesufficientstructuralstabilityunderfireconditionstoallowcollapseofconstructiononeithersidewithoutcollapseofthewallforthedurationoftimeindicatedbytherequiredfire-resistanceratingorshallbeconstructedasdoublefirewallsinaccordancewithNFPA221.

2HourFireWallAssembly

2"HOUR DOUBLE STUD WALL

2 X FRAMING AT 16" O.C.

2"HOUR RATING PER GA FILE NO. WP 3820

WOOD STRUCTURAL PANELS WHEREREQUIRED FOR SHEAR

RESILIENT DRAFT STOPS ATMAX. 10' O.C. HORIZONTAL

2 LAYERS 5/8" TYPE 'X' GYPSUMBOARD EACH SIDE

BATT INSULATION AS REQUIRED FOR THERMAL/ACOUSTICALPERFORMANCE

AIR

GAP

0' "

1"

ConstructionType:• V


ConstructionType:• V


ConstructionTypes:• III• IV• V

AlsoseeULU336


2"HOUR FIRE WALL ASSEMBLY

2 1/2" METAL STUDS AT 24" O.C.

2 LAYERS 5/8" TYPE 'X' GYP. BD. ON EACH SIDE OF METAL STUDS

WOOD STRUCTURAL PANELS WHERE REQUIRED FOR SHEAR

2"HOUR RATING PER GA FILE NO. WP 1548

WOOD STUD WALLS ON EITHERSIDE OF FIRE WALL

AIR

GA

P

0' "

1"

AIR

GA

P

0' "

1"

INTERIOR OR EXTERIOR FINISH AS REQUIRED

BATT INSULATION (OPTIONAL)

CAD&RevitDetails:www.woodworks.org


GAWP1548ULU411


2"HOUR FIRE WALL AT FLOOR/CEILING

2"HR. ASSEMBLY: 2 1/2" METALSTUDS WITH 2 LAYERS 5/8" TYPE 'X'

GYP. BD. EACH SIDE

CONTINUOUS STRUCTURAL WOODPANELS " USE FIRE"TREATED PANELS

THROUGH WALL CAVITY¹

¹CONSULT LOCAL JURISDICTION HAVING AUTHORITY FOR ACCEPTANCE OF FIRE"TREATED WOODPANELS RUNNING THROUGH 2"HOUR ASSEMBLY IN THIS APPLICATION.

RIM JOIST WITH SOLID BLOCKING

2"HOUR FIRE CAULKING

1" AIR GAP

RESILIENT CHANNELS

2 X 4 STUD WALL EACH SIDE, WITHSTRUCTURAL WOOD PANELS AS

REQUIRED FOR SHEAR AND 1 LAYER5/8" TYPE 'X' GYP. BD.

SAWN LUMBER FRAMING WITH WOOD PANEL DIAPHRAGM RUNNING THROUGH FIRE WALL



GAWP1548ULU411



Caninstallwoodbearingwalloneachsideof2hourwall


3"HOUR FIRE WALL ASSEMBLY

1 5/8" METAL STUDS AT 24" O.C. MAX.

3 LAYERS 1/2" TYPE 'X' GYP. BD. ON EACH SIDE OF METAL STUDS

WOOD STRUCTURAL PANELS WHERE REQUIRED FOR SHEAR

3 HOURS PER UL DESIGN NO. U435

WOOD STUD WALLS ON EITHERSIDE OF FIRE WALL

AIR

GAP

0' "

1"

AIR

GAP

0' "

1"

INTERIOR OR EXTERIOR FINISH AS REQUIRED

BATT INSULATION (OPTIONAL)



• (2)1”TypeXGypsum• 2”HStuds• 2”mineralfiberinsulation

eachside


Couldinstallwoodbearingwalloneachsideof3hourwall


Couldinstallwoodbearingwalloneachsideof3hourwall

FireWalls– SeismicDiaphragmContinuity


3"HOUR FIRE WALL AT FLOOR/CEILING


GYP. BD. EACH SIDE


1" AIR GAP

RESILIENT CHANNELS



CONTINUOUS 13 1/2" WIDE 14 GA. GALV.SHT. METAL

CONTINUOUS 16 GA. TRACK TOP ANDBOTTOM

FIRE SAFING

CONTINUOUS 16 GA. COMP. CHANNEL

WOOD TRUSS FRAMING WITHOUT WOOD PANEL DIAPHRAGM RUNNING THROUGH FIRE WALL3"HOUR FIRE WALL AT FLOOR/CEILING


GYP. BD. EACH SIDE

CONTINUOUS STRUCTURAL WOODPANELS " USE FIRE"TREATED PANELS

THROUGH WALL CAVITY¹

¹CONSULT LOCAL JURISDICTION HAVING AUTHORITY FOR ACCEPTANCE OF FIRE"TREATED WOODPANELS RUNNING THROUGH 3"HOUR ASSEMBLY IN THIS APPLICATION.

RIM JOIST WITH SOLID BLOCKING


1" AIR GAP

RESILIENT CHANNELS



I"JOIST FRAMING WITH WOOD PANEL DIAPHRAGM RUNNING THROUGH FIRE WALL

FireWalls– SeismicDiaphragmContinuity

FireBarriers– IBC707

Commonlyusedin:• Shaftenclosures• Interiorexitstairway• Exitstairwayenclosures• Exitpassageways• Incidentaluses• Separatedoccupancies• FireAreas

2012IBCCode&Commentary

FireBarrierExample

FireBarriers– IBC707FireBarriers:§ Maybeconstructedwithanymaterialspermittedbythe

constructiontype§ FireResistanceRatings:• ShaftEnclosures:IBC713.4

• 2Hr whenconnecting4storiesormore,1hr ifless• SeparatedOccupancies:IBCTable508.4• FireAreas:IBCTable707.3.10


707.5:Continuity:Firebarriersshallextendfromthetopofthefoundationorfloor/ceilingassemblybelowtotheundersideofthefloororroofsheathing,slabordeckaboveandshallbesecurelyattachedthereto.Suchfirebarriersshallbecontinuousthroughconcealedspace,suchasthespaceaboveasuspendedceiling

707.5.1SupportingConstruction:Thesupportingconstructionforafirebarriershallbeprotectedtoaffordtherequiredfire-resistanceratingofthefirebarriersupported.Hollowverticalspaceswithinafirebarriershallbefireblocked inaccordancewithSection718.2ateveryfloorlevel.

Otherrequirementsforopenings,penetrations,joints


CommonDetailingMethod:FireBarrier&membraneextendtoundersideoffloordeckabove

FirePartitions– IBC708

Commonlyusedtoseparate:• Dwellingorsleeping

unitsinsamebldg.• Tenantspacesinmalls• CorridorwallsMinimum1hr ratingexcept:• Somecorridors• Separatedwellingunits

inVBandIIB

2012IBCCode&Commentary

FirePartitionExample

FirePartitions– IBC708FirePartitions:§ Maybeconstructedwithanymaterialspermittedbythe

constructiontype§ 708.3FireResistanceRatings:• Firepartitionsshallhaveafire-resistanceratingofnotless

than1hour.Exceptions:1.Corridorwallspermittedtohavea1/2 hourfire-resistanceratingbyTable1018.1.2.DwellingunitandsleepingunitseparationsinbuildingsofTypeIIB,IIIBandVBconstructionshallhavefire-resistanceratingsofnotlessthan1/2 hourinbuildingsequippedthroughoutwithanautomaticsprinklersysteminaccordancewithSection903.3.1.1.

FirePartitions– IBC708708.4Continuity.Firepartitionsshallextendfromthetopofthefoundationorfloor/ceilingassemblybelowtotheundersideofthefloororroofsheathing,slabordeckaboveortothefire-resistance-ratedfloor/ceilingorroof/ceilingassemblyabove,andshallbesecurelyattachedthereto.Incombustibleconstructionwherethefirepartitionsarenotrequiredtobecontinuoustothesheathing,deckorslab,thespacebetweentheceilingandthesheathing,deckorslababoveshallbefireblocked ordraftstopped inaccordancewithSection718.2and718.3atthepartitionline.Thesupportingconstructionshallbesupportedtoaffordtherequiredfire-resistanceratingofthewallsupported,exceptfor...wallsseparatingdwellingunits,wallsseparatingsleepingunits,andcorridorwalls,inbuildingsofTypeIIB,IIIBandVBconstruction.

FirePartitions– IBC707

CommonDetailingMethod:FirePartition&membranestopatundersideofratedfloor/ceilingwithfireblocking/draftstopping ifrequired

Outline



Detailing:ShaftWallsvs.ExteriorWalls

IBC713.2:ShaftWallsshallbeconstructedasFireBarriers

KeyDifferencesbetweenExteriorWallsandShaftWalls(FireBarriers)• Continuity• SupportingConstruction• FireResistanceRatings• ConstructionMaterials


ShaftWallRequirements:

707.5:FireBarrierContinuity:• Mustextendfromtopofthefoundationorfloor/ceiling

assemblybelowtotheundersideofthefloororroofsheathing

• Throughconcealedspaces

707.5.1:SupportingConstruction:• Thesupportingconstructionfora

firebarriershallbeprotectedtoaffordtherequiredfire-resistanceratingofthefirebarriersupported.


ShaftWallRequirements:

713.4Fire-ResistanceRating:• 2hours(4storiesormore)• 1hour(lessthan4stories)• Numberofconnectedstoriesincludesbasementbutnot

mezzanine• Fireratingshallnotbelessthanfloorassemblypenetrated,

butneednotexceed2hours

707.2:ConstructionMaterials:• Anypermittedbyconstructiontype• FRTWnotrequiredforshaftwallsintypesIII,IV,V


Howdoweachievetheserequirements?

Continuity:Thegeneralrequirementsin707.5werenotwrittenwithplatformconstructioninmind...theywereattemptingtoprecludelargeopenconcealedspacestoprovideacontinuousbarrierbetweenoneportionofthebuildingandanother

Manyjurisdictionshaverecognizedthatcontinuityofthefirebarrier’sfireprotectioncanbemaintainedevenifthewallframing doesnotextendtotheundersideofthedeckingabove


SupportingConstruction:Musthavesamefireresistanceratingasfirebarrierbeingsupported


SupportingConstruction:Inplatformandsemi-balloonframeconstruction,ifwehavea2hourshaftwallanda1hourfloor,howdoweachievethis?Ifweareabletodemonstratethewall’s2hourcontinuity,shouldnotneedtoconsiderthefloor“supportingconstruction”?

1HourFloor

2HourWall


TypesofShafts:• Elevator• Stair• Mechanical

Somepointsofshaftwallconstructionapplytoanytypeofshaft.Someareuniquetoeachtypeofshaft.

ShaftWalls

MasonryShaftWalls

MasonryShaftWalls

Mixingmasonryshaftwallswithwoodfloorframingcancreateseveralissues:• Masonryshaftwallscanbecomepartofbuilding’s

lateralforceresistingsystem,increasingseismicforcesandaddingmass

• Differentialshrinkagebetweenwoodandmasonry

• Bestpracticesincludeseismicallyisolatingmasonryshaftwalls,onlytiewoodfloortomasonryshaftwhererequired(i.e.atelevatordoorthreshold)

MasonryShaftWalls

CMUshaftwall

MasonryShaftWallDetail

Floorframingandwoodbearingwalls

MasonryShaftWalls

CMUshaftwall

MasonryShaftWallDetail

Floorbeam,joists&sheathing

ShaftWallMaterialChoice

Whydoweintroducenewmaterialsforourshaftwalls?Theycanbeframedwithwood!

WoodFramedShaftWalls

WoodFramedShaftWalls

Usingwoodframedshaftwallscan:• Eliminatelateralloadconsiderationsassociatedwithattaching

wooddiaphragmstoconcreteormasonryshaftwalls(SDPWS4.1.5)

• Eliminatedifferentialshrinkageatfloortowalltransition• Eliminatedifferentconstructiontradesinbuildingduring

construction• Reducecosts• Improveschedule

ShaftWallDetails

WoodDesignFocus:Volume22,Issue3bySmith

Rimjoist

Floorjoists

2layers5/8”thk.Type“X”GWBeachsidefor2hr.rating(ULU301)

2xstudsDbl.rowofsolidblockingtocontinuefirerating

WSPsht’gasrequired

Concretetopping

Considerations:• Shrinkageinrim&floorjoist• Acoustics


bothsideofwallprovidefireresistanceviatheirapprovedassembly;atfloorcavity2layersofblockingprovide2hrprotectionthroughcharcalculations

ShaftSide

FloorSide

ShaftWallDetails

Rationalefordetailapproval:• Membranesonbothsidesofwallprovidefire

resistanceviatheirapprovedassemblyandarecontinuous.FRTfloorsheathingcanbeinsuranceforminimalpenetrationofmembrane.

ShaftSide FloorSide

ShaftWallsw/Shaftliner

Rationalefordetailapproval:• Shaftlinerassemblyprovidesfireresistance

independentofframingmaterialoneitherside.

ShaftSide FloorSide

Floorsidewallprovidestypicalfloorsupport

Shaftliner inH-studsattachedtowallwithclips

Shaftsidewallprovidesshaftframing(stair,elevatorrail)support

ShaftWallsw/HStuds&Shaftliner

Source:GeorgiaPacific

Source:USGypsum


SingleWallOption

Source:ULU375DoubleWallOption

HStudAttachmentClips

ExampleShaftliner ClipAttachment ScheduleperULU375SystemNo. SystemHeight

LimitationAttachment ClipSchedule

1 23ft 10ft o.c.2 44ft Baseto20 ft:5ft o.c.

20ft to44ft:10ft o.c.3 66ft Baseto22ft:3’-4”o.c.

22ft to42ft:5ft o.c.42ft to66ft:10ft o.c.

AttachmentClips:Aluminumorsteelangles,usually14– 16gauge,2”widewith2”to2-1/2”longlegs.AttachestowallframingandH-studs

H-StudSource:Clarkdietrich

ShaftWallsw/ShaftlinerCanalsoutilizewoodframedshaftwallson3sidesandCHstudswithshaftliner on4th side

ShaftWallsw/CHorCTStuds2hourwallswithC-HStuds,shaftliner,and

gypsumpanels

ShaftWallsw/CHorCTStuds

ShaftWallsw/CHorCTStuds

Somewallmanufacturerswilllistatotalsystemheightlimitation.Ifthisisnotarequirementofthetestedassembly(i.e.ULorsim.requirement)canalsoperformastructuralanalysisofthewalls,especiallywhenstackingmultiplestories,toverifyadequacy

Source:Clarkdietrich

StairwayShaftEnclosures&FramingWoodFramedWallon

3SidesofShaft

CHStudsw/Shaftlineron4th SideofShaft

ElevatorShaftWalls

WoodFramedElevatorShaftWall

WoodFramedElevatorRailSupports

WoodFramedElevatorRailDetails

ElevatorShaftWall

WoodDesignFocus:Volume22,Issue3bySmith

Rimjoist

Floorjoists

2layers5/8”thk.Type“X”GWBeachsidefor2hr.rating

Doublestudwall Dbl.rowofsolidblockingtocontinuefirerating

Concretetopping

Nailerplate

WSPsht’gasrequired

Elevatorguiderailsandsupportbracketwithslottedholes

Galvanizedmetalspacer

Considerations:• Shrinkage• Improvedacoustical

performancewithdoublewall


bothsideofwallprovidefireresistanceviatheirapprovedassembly.2layersof2xblockinginfloorcavitycontinueprotection

ShaftSide FloorSide

Considerations:• Shrinkageinrim&floorjoist/differentialshrinkage• Doublewallprovidesimprovedacoustics

ElevatorShaftWall

Floorjoists

2layers5/8”thk.Type“X”GWBeachsidefor2hr.rating

Doublestudwall

Concretetopping

Nailerplate

WSPsht’g asrequired

Elevatorguiderailsandsupportbracketwithslottedholes

Galvanizedmetalspacer


bothsideofwallprovidefireresistanceviatheirapprovedassemblyTopflangejoist

hangerapprovedtospan2layersGWB

ShaftSide FloorSide

StairShaftWalls

StairwayShaftEnclosures&Framing

ExteriorBearingWall

IntermediateLandingFramingElev.=94’-8”

CorridorFramingElev.=100’-0”

Floo

rFraming

Elev.=100

’-0”

IndicatesDownwardStairTravelPath

LandingFramingElev.=100’-0”

Floo

rFraming

Elev.=100

’-0” Structural

Beam

ShaftWalls

WoodFramedStairShaftWalls


TypicalFloorjoist

StairFraming(Landing&Stringers)

Attachmentofstairframingtoshaftwallthroughgypsum,typically2layers

Shaftwall

Stair&FloorCommonWallDetail

Rationalefordetailapproval:• 2layersofwallmembrane

provide2hr protection


TypicalFloorjoist

Shaftwall

Stair&FloorCommonWallDetail


wallprovidefireresistanceviatheirapprovedassembly

IntermediateStairLanding

FramingAttachledgertoeachshaftwallstudwithfasteners(woodscrews,lagscrews)designedtoaccountforgypsum

StairShaftSide

FloorSide


StairFraming(Landing&Stringers) Attachmentofstair

framingtoshaftwallthroughgypsum,typically2layers

Shaftwall

Consider“Hinge”atwallplatesforout-of-planewind&seismicloadsduetolackofadjacentfloor:• SpanPlates

Horizontally(nojoints)• Installadditional

member(rim)tospanhorizontally

StairExteriorWallDetail

Rationalefordetailapproval:• 2layersofwallmembrane

provide2hr protection



WhenStairShaftWallisExteriorWall

WallPlatesatTypicalFloorElevation– CreatesPotential“Hinge”



Framing Attachledgertoeachshaftwallstudwithfastenersdesignedtoaccountforgypsum

Shaftwall




StairShaftSide

ExteriorSideConsider“Hinge”atwallplatesforout-of-planewind&seismicloadsduetolackofadjacentfloor:• Spanplateshorizontally• Installadditional




Framing Attachledgertoeachshaftwallstudwithfastenersdesignedtoaccountforgypsum

Shaftwall




StairShaftSide

ExteriorSideConsider“Hinge”atwallplatesforout-of-planewind&seismicloadsduetolackofadjacentfloor:• Installadditional




ExteriorWallPlateElevationsShiftedDowntoIntermediate

LandingElevation

• EliminatesHingeEffect• AvoidsInterferencewith

LandingWindows

WhenStairShaftWallisExteriorWall



Framing Attachledgertoeachshaftwallstudwithfasteners(woodscrews,lagscrews)designedtoaccountforgypsum

Shaftwall Wallplateelevationsshiftedtointermediatelandingelevationatstairshafts




StairShaftSide

ExteriorSide



Framing

Topflangejoisthangerapprovedtospan2layersGWB

ShaftwallWallplateelevationsshiftedtointermediatelandingelevationatstairshafts




StairShaftSide

ExteriorSide


StairLandingFraming

Attachledgertostudswithfasteners(woodscrews,lagscrews)designedtoaccountfor1layerofgypsum

Shaftwall Blockinginshaftwallbetweenstuds

Wallplatesattypicalfloorelevation

LedgerInterruptsOneLayerofShaft

WallGypsum

StairWallDetail


wallprovidefireresistanceviatheirapprovedassembly;atfloorcavity,blockinginwallprovides2nd hr

StairShaftSide

ExteriorSide


StairLandingFraming Attachledgertoblocking

withfasteners(woodscrews,lagscrews)

Shaftwall2layersofblockinginshaftwallbetweenstudstoprovide2hoursprotection&ledgerfastenerattachment


StairWallDetail


wallprovidefireresistanceviatheirapprovedassembly;atfloorcavity2layersofblockinginwallprovide2hr protection

StairShaftSide

ExteriorSide



Framing

Shaftwall Wallplateelevationsshiftedtointermediatelandingelevationatstairshafts




StairShaftSide

ExteriorSide

Installspanningbeamjustinboardofshaftwall -onlypenetratewallatendofbeamlocations–requiresintermediateheightposts

FloorBm


Wallplateelevationsshiftedtointermediatelandingelevationatstairshafts




StairShaftSideExteriorSide

Shaftwall

IntermediateLandingFloorSheathingmayStopatLandingWallifLandingWallisAdequatelyBraced

Landingandstairframingsupportedonindependent

bearingwalls– shouldconsiderlateralbracingof

independentwalls


Framing


StairFraming(Landing&Stringers)

Landingandstairframingsupportedonindependentbearingwalls– shouldconsiderlateralbracingofindependentwalls

Shaftwall




StairWallDetail

StairShaftSide ExteriorSide


ExteriorBearingWall


CorridorFramingElev.=100’-0”

Floo

rFraming

Elev.=100

’-0”

IndicatesDownwardStairTravelPath


Floo

rFraming

Elev.=100

’-0”

IntermediateLandingBeamConcentratedLoad



Framing

Shaftwall



wallprovidefireresistanceviatheirapprovedassembly;atfloorcavitybeamoversizedtoprovide2hourcharprotection

StairShaftSide

ExteriorSide

IntermediateLandingBeamExtendsintoShaftWall– OversizetoProvide2HourFireProtectionUsingCalculatedCharRates


2Hr protectionprovidedall

aroundbeamvia.blocking

Beambearsdirectlyonaxiallyloadedpost–shrinkageconcernsareminimized

Outline



Corridors– FireResistanceRatings

CheckrequirementsofIBCTables601and1018.1forCorridorWallandFloor/CeilingFire-ResistanceRatings

Corridors– FireResistanceRatings

CorridorWalls

IBC1018.1:Corridorwallsrequiredtobefire-resistanceratedshallcomplywithSection708forfirepartitions.

708.3Fire-resistancerating.Firepartitionsshallhaveafire-resistanceratingofnotlessthan1hour.

Exception:Corridorwallspermittedtohavea1/2hourfire-resistanceratingbyTable1018.1(appliestoRoccupancieswithsprinklersystems)

CorridorWalls708.4Continuity.Firepartitionsshallextendfromthetopofthefoundationorfloor/ceilingassemblybelowtotheundersideofthefloororroofsheathing,slabordeckaboveortothefire-resistance-ratedfloor/ceilingorroof/ceilingassemblyabove,andshallbesecurelyattachedthereto.Exceptions:2.Wheretheroom-sidefire-resistance-ratedmembraneofthecorridoriscarriedthroughtotheundersideofthefloororroofsheathing,deckorslabofafire-resistance-ratedfloororroofabove,theceilingofthecorridorshallbepermittedtobeprotectedbytheuseofceilingmaterialsasrequiredfora1-hourfire-resistance-ratedfloororroofsystem.3.Wherethecorridorceilingisconstructedasrequiredforthecorridorwalls,thewallsshallbepermittedtoterminateattheuppermembraneofsuchceilingassembly.

CorridorWalls– 708.4Exception2

CorridorWalls– 708.4Exception3

• 1”gypsumunderlayment• 19/32”WSP• 3½”FiberglassBatt• 2x10joists@24“oc• Resilientchannel• 5/8”Type-XGyp

Corridors- 1hrFloor

ULL502GAFC5104

Corridordecking

Floorsheathing

Joisthangerifjoistsperpendiculartowall

Corridors- 1hrFloor

Untreated

FRTWood

Legend

Thinnerframingwithdroppedceilingallowsmainmechanicallinestorunincorridor

Balconies– IBC1406.3

BalconiesofcombustibleconstructionandnotFRTshallbe:• Ratedinaccordancew/Table601forfloors• OrbeofTypeIV• Andshallnotexceed50%ofbldgperimeterExceptions• BalconiesinTypeIII,IVandVcanbeoftypeV

constandshallnothavefireresistanceratingifsprinklerprotectionprovided

• Untreatedwoodispermittedforrailsandguardrails

Balconies– IBC1406.3

So….ForTypeIIIorVbalconyoptionsare:

1. Non-combustible– nosprinklers/nofirerating2. FRT– nofiresprinklers/nofirerating3. TypeIV– nofiresprinklers/nofirerating4. Nontreated– firesprinkler/nofirerating5. Nontreated– fireratedper601&602/nosprinkler

Balconies– ExteriorWallPenetration

FloorsheathingFRTdecking

TopflangeJoisthangerapprovedtospan2layersGWB

Cantileverbeam

Cantileverknifeplatesupport

Exteriorveneerasoccurs

Caulking,sealantsvaporbarriers,and flashingnotshownforclarity

Questions?

ThisconcludesTheAmericanInstituteofArchitectsContinuingEducationSystemsCourse

Visitwww.woodworks.org formoreeducationalmaterials,casestudies,designexamples,aprojectgallery,andmore

ThispresentationisprotectedbyUSandInternationalCopyrightlaws.

Reproduction,distribution,displayanduseofthepresentationwithoutwrittenpermission

ofthespeakerisprohibited.

©TheWoodProductsCouncil2016

CopyrightMaterials

15LL11 Practical Code Compliant Detailing for Mid-Rise ... · 2. Examine a variety of...

Documents

Transcript of 15LL11 Practical Code Compliant Detailing for Mid-Rise ... · 2. Examine a variety of...