aisi cfs framing general provisions s200-12

iwricareioflg/,

AISIS200-12

iPliiirSSteeliui

AISISTANDARD

NorthAmericanStandardfor

Cold-FormedSteelFraming

GeneralProvisions

2012Edition

ii

AISIS200-12

DISCLAIMERThematerialcontainedhereinhasbeendevelopedbytheAmericanIronandSteelInstitute(AISI)CommitteeonFramingStandards.TheCommitteehasmadeadiligentefforttopresentaccurate,reliable,andusefulinformationoncold-formedsteelframingdesignandinstallation.TheCommitteeacknowledgesandisgratefulforthecontributionsofthenumerousresearchers,engineers,andotherswhohavecontributedtothebodyofknowledgeonthesubject.SpecificreferencesareincludedintheCommentary.Withanticipatedimprovementsinunderstandingofthebehaviorofcold-formedsteelframingandthecontinuingdevelopmentofnewtechnology,thismaterialwillbecomedated.ItisanticipatedthatAISIwillpublishupdatesofthismaterialasnewinformationbecomesavailable,butthiscannotbeguaranteed.Thematerialssetforthhereinareforgeneralpurposesonly.Theyarenotasubstituteforcompetentprofessionaladvice.Applicationofthisinformationtoaspecificprojectshouldbereviewedbyadesignprofessional.Indeed,inmanyjurisdictions,suchreviewisrequiredbylaw.Anyonemakinguseoftheinformationsetforthhereindoessoattheirownriskandassumesanyandallliabilityarisingtherefrom.

1stPrinting-April2013

CopyrightAmericanIronandSteelInstitute2012

NorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012Edition

PREFACETheAmericanIronandSteelInstitute(AISI)CommitteeonFramingStandardshasdevelopedAISIS200,NorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,toaddressrequirementsforconstructionwithcold-formedsteelframingthatarecommontoprescriptiveandengineereddesign.ThisstandardisintendedforadoptionanduseintheUnitedStates,CanadaandMexico.Thiseditionsupersedesthepreviousedition,designatedasAISIS200-2007.Comparedwiththe2007editionofthestandard,thefollowingmajorrevisionsweremade:(1)ConsolidationsandclarificationsweremadebetweenAISIcold-formedsteelframingstandardsregardingapplicablematerial,materialspecification,basesteelthickness,manufacturingtolerances,andproductdimensions.Asaresult,thefollowingsectionswererevised:A3,Material;A4,CorrosionProtections;andA5,Products.(2)SectionC3.4.4,EndBearing,wasrevisedtoclarifywhenthestudendgapneedstobeconsideredandspecified.(3)ProvisionsrelatedtononstructuralmembersweremovedfromthisstandardtoAISIS220.ChangesweremadeinSectionsAl,Scope;A3,Material;A4,CorrosionProtection;andSectionA5,Products.(4)SectionA2,Definitions,wasrevisedtoincludethoseusedinothercold-formedsteelframingstandards.(5)SectionA6,ReferencedDocuments,wasupdated.Whilenotnecessary,useofthemorestringentrequirementsforstructuralmembersthatareinthisstandardfornonstructuralmembersshouldbepermitted,sincetheseshoulddemonstrateequivalentperformancefortheintendedusetothosespecifiedinAISIS220.TheCommitteeacknowledgesandisgratefulforthecontributionsofthenumerousengineers,researchers,producersandotherswhohavecontributedtothebodyofknowledgeonthesubjects.TheCommitteewishestoalsoexpressitsappreciationforthesupportoftheCanadianSheetSteelBuildingInstitute.

ivAISIS200-12

ThisPageisIntentionallyLeftBlank.RichardHaws,ChairmanNucorCorporation

SteveFox,ViceChairmanCanadianSheetSteelBuildingInstitute

HelenChen,SecretaryAmericanIronandSteelInstitute

DonAllenDSi-Engineering,LLC

BillBabichITWBuildingComponentsGroup

JeffBrinkNationalCouncilofStructuralEngineersAssociation

BradCameronCameron&AssociatesEngineering

RandyDaudetSimpson-StrongTie

NaderElhajjFrameCADSolutions

PatFordSteelFramingIndustryAssociation

CurtKinneySuperStudBuildingProducts

JeffKlaimanADTEKEngineers

RogerLaBoubeWei-WenYuCenterforCold-FormedSteelStructures

RobMadsenSupremeSteelFramingSystemAssociation

JohnMatsenMatsenFordDesignAssociates

CrisMoenVirginiaPolytechnicInstituteandStateUniversity

JimMosesLiteSteelTechnologiesAmerica

KennethPaganoScostaCorporation

MikePellockAegisMetalFraming

NabilRahmanTheSteelNetwork

GregRalphClarkDietrichBuildingSystems

BenSchaferJohnsHopkinsUniversity

FernandoSesmaCaliforniaExpandedMetalProducts

SuttonStephensPacificNorthwestEngineering

TomTrestainT.W.J.TrestainStructuralEngineering

StevenWalkerStevenH.Walker,P.Eng.

RobertWesselGypsumAssociation

LeiXuUniversityofWaterloo

ChengYuUniversityofNorthTexas

RahimZadehSteelStudManufacturersAssociation


AISICOMMITTEEONFRAMINGSTANDARDS

V

DonAllen,ChairmanDSi-Engineering,LLC

HelenChen,SecretaryAmericanIronandSteelInstitute

BillBabichITWBuildingComponentsGroup

JeffBrinkNationalCouncilofStructuralEngineersAssociation

RandyDaudetSimpsonStrong-Tie

JimDesLaurierMarino\WARE

NaderElhajjFrameCADSolutions

PatFordSteelFramingIndustryAssociation

SteveFoxCanadianSheetSteelBuildingInstitute

RichardHawsNucorCorporation

CurtKinneySuperStudBuildingProducts,Inc.

JeffKlaimanADTEKEngineers

RogerLaBoubeWei-WenYuCenterforCold-FormedSteelStructures

StephenLinchTellingIndustries

JohnMatsenMatsenFordDesignAssociates

BrianMcGloughlinMBABuildingSupplies

JimMosesLiteSteelTechnologiesAmerica,LLC

KennethPaganoScostaCorporation

GregRalphClarkDietrichBuildingSystems

FernandoSesmaCaliforniaExpandedMetalProducts

RahimZadehSteelStudManufacturersAssociation

vi

GENERALPROVISIONSSUBCOMMITTEE

AISIS200-12


vii

TABLEOFCONTENTSNORTHAMERICANSTANDARDFORCOLD-FORMEDSTEELFRAMING-GENERALPROVSIONS

DISCLAIMERiiPREFACEiiiAISICOMMITTEEONFRAMINGSTANDARDSvGENERALPROVISIONSSUBCOMMITTEEviNORTHAMERICANSTANDARDFORCOLD-FORMEDSTEELFRAMING-GENERALPROVISIONS....!A.GENERAL1A1Scope1A2Definitions1A3Material7A4CorrosionProtection7A5Products8A5.1BaseSteelThickness8A5.2MinimumFlangeWidth8A5.3ProductDesignator8A5.4ManufacturingTolerances8A5.5ProductIdentification10A6ReferencedDocuments10B.MEMBERDESIGN12B1Members12B2MemberCondition12B2.1WebHoles12B2.2Cutting,PatchingandSplicing12C.INSTALLATION13CIIn-LineFraming13C2InstallationTolerances13C2.1Foundation13C2.2GroundContact13C2.3Floors14C2.4Walls14C2.5RoofsandCeilings14D.CONNECTIONS16D1ScrewConnections16Dl.lSteel-to-SteelScrews16D1.2SheathingScrews16D1.3Installation16D1.4StrippedScrews16D1.5SpacingandEdgeDistance16D1.6GypsumBoard16D2WeldedConnections16D3OtherConnections17D3.1Bolts17D3.2OtherConnectors17D3.3ConnectiontoOtherMaterials17E.MISCELLANEOUS18ElUtilities18

viiiAISIS200-12

El.lHoles18El.2Plumbing18El.3Electrical18E2Insulation18E2.1MineralFiberInsulation18E2.2OtherInsulation18


1

NORTHAMERICANSTANDARDFORCOLD-FORMEDSTEELFRAMING-GENERALPROVISIONS

A.GENERAL

A1ScopeThisstandardshallapplytothedesignandinstallationofstructuralmembersutilizedincold-formedsteelframingapplicationswherethespecifiedminimumbasesteelthicknessisnotgreaterthan118mils(0.1180inches)(2.997mm).Elementsnotspecificallyaddressedbythisstandardshallbeconstructedinaccordancewithapplicablebuildingcoderequirementsoranapproveddesign.Thisstandardshallnotprecludetheuseofothermaterials,assemblies,structuresordesignsnotmeetingthecriteriaherein,whentheothermaterials,assemblies,structuresordesignsdemonstrateequivalentperformancefortheintendedusetothosespecifiedinthisstandard.Wherethereisaconflictbetweenthisstandardandotherreferencedocuments,therequirementscontainedwithinthisstandardshallgovern.ThisstandardincludesSectionsAthroughEintheirentirety.A2Definitions

Inthisstandard,"shall"isusedtoexpressamandatoryrequirement,i.e.,aprovisionthattheuserisobligedtosatisfyinordertocomplywiththestandard.Provisionsdescribedas"permitted"areoptional,andtheelectiontousesuchprovisionsisatthediscretionoftheuser.Wherethefollowingtermsappearinthisstandardinitalics,theyshallhavethemeaninghereinindicated.TermsincludedinsquarebracketsshallbespecifictoLimitStatesDesign(LSD)terminology.Whereacountryisindicatedinsquarebracketsfollowingthedefinition,thedefinitionshallapplyonlyinthecountryindicated.TermsnotdefinedinSectionA2shallhavetheordinaryacceptedmeaningforthecontextforwhichtheyareintended.AdjustedShearResistance.InTypeIIshearwalls,theunadjustedshearresistancemultipliedbytheshearresistanceadjustmentfactor.AmplifiedSeismicLoad.Loaddeterminedinaccordancewiththeapplicablebuildingcodeseismicloadcombinationsthatincludesthesystemoverstrengthfactor,Qq,forstrengthdesign(LRFD)orforallowablestrengthdesign(ASD).[USAandMexico]ASD{AllowableStrengthDesign).MethodofproportioningstructuralcomponentssuchthattheallowablestrengthequalsorexceedstherequiredstrengthofthecomponentundertheactionoftheASDloadcombinations.[USAandMexico]ASDLoadCombination.Loadcombinationintheapplicablebuildingcodeintendedforallowablestressdesign{allowablestrengthdesign).[USAandMexico]AllowableStrength.NominalstrengthdividedbythesafetyfactorRn/Q.[USAandMexico]AllowableStressDesign.Alsoknownasallowablestrengthdesign,anoutdatedtermusedinsomereferencedocuments.[USAandMexico]ApplicableBuildingCode.Thebuildingcodeunderwhichthebuildingisdesigned.Approved.Approvedbytheauthorityhavingjurisdictionordesignprofessional.AvailableStrength.Designstrengthorallowablestrength,asappropriate.[USAandMexico]AverageGrade.Theaverageelevationofthefinishedgroundleveladjoiningthebuildingat

2

AISIS200-12

allexteriorwalls.BaseSteelThickness.Thethicknessofbaresteelexclusiveofallcoatings.BearingStiffener.Additionalmaterialthatisattachedtothewebtostrengthenthememberagainstwebcrippling.Alsocalledawebstiffener.Blocking.C-shapedmember,breakshape,flatstrapmaterial,orcomponentassembliesattachedtostructuralmembers,flatstraporsheathingpanelstotransfershearforcesorstabilizemembers.BoundaryMember.Diaphragmandshearwallboundarymembertowhichthediaphragmtransfersforces.Boundarymembersincludechordsanddragstrutsatdiaphragmandshearwallperimeters,interioropenings,discontinuitiesandre-entrantcorners.BracedWallLine.AwallthatisconstructedtoresistrackingfromseismicorwindforcesandthatcontainsaseriesofTypeIbracedwallpanelsorTypeIIbracedwalls.Bracing.Structuralelementsthatareinstalledtoproviderestraintorsupport(orboth)tootherframingmemberssothatthecompleteassemblyformsastablestructure.CapacityBasedDesign.Methodfordesigningaseismicforceresistingsysteminwhicha)specificelementsormechanismsaredesignedtodissipateenergy;b)allotherelementsaresufficientlystrongforthisenergydissipationtobeachieved;c)structuralintegrityismaintained;d)elementsandconnectionsinthehorizontalandverticalloadpathsaredesignedtoresisttheseseismicloadsandcorrespondingprincipalandcompanionloadsasdefinedbytheNBCC;e)diaphragmsandcollectorelementsarecapableoftransmittingtheloadsdevelopedateachleveltotheverticalseismicforceresistingsystem;andf)theseloadsaretransmittedtothefoundation.[Canada]CeilingJoist.Ahorizontalstructuralmemberthatsupportsceilingcomponentsandwhichmaybesubjecttoatticloads.Chord.Memberofashearwallordiaphragmthatformstheperimeter,interioropening,discontinuityorre-entrantcorner.ChordMember.Astructuralmemberthatformsthetoporbottomcomponentofatruss.ChordSplice.Theconnectionregionbetweentwotrusschordmemberswherethereisnochangeinslope.ChordStud.Axialload-hearingstudslocatedattheendsofTypeIbracedwallpanelsorTypeIIbracedwalls.ClipAngle.AnL-shapedshortpieceofsteel(normallywitha90-degreebend)typicallyusedforconnections.Cold-FormedSheetSteel.Sheetsteelorstripsteelthatismanufacturedby(1)pressbrakingblanksshearedfromsheetsorcutlengthofcoilsorplates,orby(2)continuousrollformingofcold-orhot-rolledcoilsofsheetsteel;bothformingoperationsareperformedatambientroomtemperature,thatis,withoutanyadditionofheatsuchaswouldberequiredforhotforming.Cold-FormedSteel.SeeCold-FormedSheetSteel.Collector.Alsoknownasadragstrut,amemberthatservestotransferforcesbetweendiaphragmsandmembersofthelateralforceresistingsystem.Component.Seestructuralcomponent.Connection.Combinationofstructuralelementsandjointsusedtotransmitforcesbetweentwoormoremembers.CrippleStud.Astudthatisplacedbetweenaheaderandawindowordoorheadtrack,a


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headerandwalltoptrack,orawindowsillandabottomtracktoprovideabackingtoattachfinishingandsheathingmaterial.C-Shape.Acold-formedsteelshapeusedforstructuralandnonstructuralmembersconsistingofaweb,two(2)flangesandtwo(2)lips(edgestiffeners).CurtainWall.Awallthattransferstransverse(outofplane)loadsandislimitedtoasuperimposedverticalload,exclusiveofsheathingmaterials,ofnotmorethan100lb/ft(1.46kN/m),orasuperimposedverticalloadofnotmorethan200lbs(0.890kN).DeflectionTrack.Atrackmanufacturedwithextended/Zangesandusedatthetopofawalltoprovideforverticalmovementofthestructure,independentofthewallstud.DesignLoad.AppliedloaddeterminedinaccordancewitheitherLRFDloadcombinationsorASDloadcombinations,whicheverisapplicable.[USAandMexico]DesignProfessional.Anindividualwhoisregisteredorlicensedtopracticetheirrespectivedesignprofessionasdefinedbythestatutoryrequirementsofthestate,provinceorterritoryinwhichtheprojectistobeconstructed.DesignStrength.ResistanceFactormultipliedbythenominalstrength,[USAandMexico]DesignThickness.Thesteelthicknessusedindesign.DesignationThickness.Theminimumbasesteelthicknessexpressedinmilsandroundedtoawholenumber.Diaphragm.Roof,floororothermembraneorbracingsystemthattransfersin-planeforcestothelateralforceresistingsystem.EaveOverhang.Thehorizontalprojectionoftheroofmeasuredfromtheoutsidefaceofexteriorwallframingtotheoutsideedgeoftheroof.EdgeStiffener.SeeLip.FactoredLoad.Productofaspecifiedloadandappropriateloadfactor.[Canada]FactoredResistance.Productofnominalresistanceandappropriateresistancefactor.[Canada]Fiberboard.Afibrous,homogeneouspanelmadefromlignocellulosicfibers(usuallywoodorcane)andhavingadensityoflessthan31poundspercubicfoot(pcf)(497kg/m3)butmorethan10pcf(160kg/m).Flange.ForaC-shape,U-shapeortrack,thatportionoftheframingmemberthatisperpendiculartotheiveb.Forafurringchannel,thatportionoftheframingmemberthatconnectsthewebs.FloorJoist.Ahorizontalstructuralmemberthatsupportsfloorloadsandsuperimposedverticalloads.Girt.Horizontalstructuralmemberthatsupportswallpanelsandisprimarilysubjectedtobendingunderhorizontalloads,suchaswindload.Grade.Thedesignationoftheminimumyieldstrength.GussetPlate.Astructuralmemberusedtofacilitatetheconnectionoftrusschordorwebmembersataheel,ridge,otherpitchbreak,orpanelpoint.Hat-Shape.Asingly-symmetricshapeconsistingofatleasttwoverticalwebsandahorizontalstiffened/Zflngewhichisusedasachordmemberinatruss.Heel.Theconnectionregionbetweenthetopandbottomtrusschordsofanon-parallelchordtruss.Header.Ahorizontalstructuralframingmemberusedoverfloor,rooforwallopeningstotransferloadsaroundtheopeningtosupportingstructuralframingmembers.

4

AISIS200-12

Hold-Down(tie-down).Adeviceusedtoresistoverturningforcesinashearwall,orupliftforcesinacold-formedsteelframingmember.JackStud.Astudthatdoesnotspanthefullheightofthewallandprovidesbearingforheaders.Joist.Astructuralmemberprimarilyusedinfloorandceilingframing.KingStud.Astud,adjacenttoajackstud,thatspansthefullheightofthewallandsupportsverticalandlateralloads.Light-FrameConstruction.Constructionwheretheverticalandhorizontalstructuralelementsareprimarilyformedbyasystemofrepetitivecold-formedsteelorwoodframingmembers.LimitStates.Thoseconditionsinwhichastructuralmemberceasestofulfillthefunctionforwhichitwasdesigned.Thosestatesconcerningsafetyarecalledtheultimatelimitstates.Theultimatelimitstateforstrengthisthemaximumload-carryingcapacity.Limitstatesthatrestricttheintendeduseofamemberforreasonsotherthansafety,suchasdeflectionandvibration,arecalledserviceabilitylimitstates.[Canada]LSD(LimitStatesDesign).Methodofproportioningstructuralcomponents(members,connectors,connectingelementsandassemblages)suchthatnoapplicablelimitstateisexceededwhenthestructureissubjectedtoallappropriateloadcombinations.[Canada]Lip.Thatpartofaframingmemberthatextendsfromtheflangeasastiffeningelement.Load.Forceorotheractionthatresultsfromtheweightofbuildingmaterials,occupantsandtheirpossessions,environmentaleffects,differentialmovement,orrestraineddimensionalchanges.LoadEffect.Forces,stresses,anddeformationsproducedinastructuralcomponentbytheappliedloads.LoadFactor.Factorthataccountsfordeviationsoftheactualloadfromthenominalload,foruncertaintiesintheanalysisthattransformstheloadintoaloadeffect,andfortheprobabilitythatmorethanoneextremeloadwilloccursimultaneously.[USAandMexico]LRFD(LoadandResistanceFactorDesign).MethodofproportioningstructuralcomponentssuchthatthedesignstrengthequalsorexceedstherequiredstrengthofthecomponentundertheactionoftheLRFDloadcombinations.[USAandMexico]LRFDLoadCombination.LoadcombinationintheapplicablebuildingcodeintendedforStrengthDesign(LoadandResistanceFactorDesign).[USAandMexico]MeanRoofHeight.Theaverageoftheroofeaveheightandtheheighttothehighestpointontheroofsurface,exceptthateaveheightshallbeusedforroofangleslessthanorequalto10degrees(0.18rad).Mil.Aunitofmeasurementequalto1/1000inch.MultipleSpan.Thespanmadebyacontinuousmemberhavingintermediatesupports.NominalLoad.Magnitudeoftheloadspecifiedbytheapplicablebuildingcode.[USAandMexico]NominalResistance.Capacityofastructureorcomponenttoresisttheeffectsofloads,determinedinaccordancewiththisstandardusingspecifiedmaterialstrengthsanddimensions.[Canada]NominalStrength.Strengthofastructureorcomponent(withouttheresistancefactororsafetyfactor)toresisttheloadeffects,asdeterminedinaccordancewiththisstandard.[USAandMexico]


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NonstructuralMember.Amemberinasteel-framedsystemthatisnotapartofthegravityloadresistingsystem,lateralforceresistingsystemorbuildingenvelope.PanelPoint.Theconnectionregionbetweenaivebandchordmember.PitchBreak.Theconnectionregionbetweentwotrusschordmemberswherethereisachangeinslope,excludingtheheel.PlanAspectRatio.Theratioofthelength(longerdimension)tothewidth(shorterdimension)ofthebuilding.Punchout.Aholemadeduringthemanufacturingprocessintheivebofasteelframingmember.Purlin.Horizontalstructuralmemberthatsupportsroofdeckandisprimarilysubjectedtobendingunderverticalloadssuchassnow,wind,ordeadloads.RakeOverhang.Thehorizontalprojectionoftheroofmeasuredfromtheoutsidefaceofagableendwalltotheoutsideedgeoftheroof.RepetitiveFraming.Aframingsystemwherethewall,floorandroofstructuralmembersarespacednogreaterthan24inches(610mm)oncenter.Largerspacesarepermittedatopeningswherethestructuralloadsaretransferredtoheadersorlintelsandsupportingstuds,joistsorrafters.RequiredStrength.Forces,stresses,anddeformationsproducedinastructuralcomponent,determinedbyeitherstructuralanalysis,fortheLRFDorASDloadcombinations,asappropriate,orasspecifiedbythisstandard.[USAandMexico]ResistanceFactor((})).Factorthataccountsforunavoidabledeviationsoftheactualstrengthfromthenominalstrength[nominalvalue]andforthemannerandconsequencesoffailure.Ridge.Thehorizontallineformedbythejoiningofthetopedgesoftwoupwardslopingroofsurfaces.RimTrack.Ahorizontalstructuralmemberthatisconnectedtotheendofafloorjoist.RoofRafter.Ahorizontalorsloped,structuralmemberthatsupportsroofloads.SafetyFactor(Q).Factorthataccountsforthedesiredlevelofsafety,includingdeviationsoftheactualloadfromthenominalloadanduncertaintiesintheanalysisthattransformstheloadintoaloadeffect,indeterminingthenominalstrengthandforthemannerandconsequencesoffailure.[USAandMexico]SeismicDesignCategory(SDC).Classificationassignedtoabuildingbaseduponitsimportanceandtheseverityofthedesignearthquakegroundmotionatthebuildingsiteasgivenintheapplicablebuildingcode.SeismicForceResistingSystem.Thatpartofthestructuralsystemthathasbeenconsideredinthedesigntoprovidetherequiredresistancetotheearthquakeforcesandeffects.[Canada]ShearWall.Wallthatprovidesresistancetolateralloadsintheplaneofthewallandprovidesstabilityforthestructuralsystem.SingleSpan.Thespanmadebyonecontinuousstructuralmemberwithoutanyintermediatesupports.Span.Theclearhorizontaldistancebetweenbearingsupports.SpecifiedLoad.Magnitudeoftheloadspecifiedbytheapplicablebuildingcode,notincludingloadfactors.[Canada]StaticLoad.Aloadorseriesofloadsthataresupportedbyorareappliedtoastructuresograduallythatforcescausedbychangeinmomentumoftheloadandstructuralelements

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AISIS200-12

canbeneglectedandallpartsofthesystematanyinstantareessentiallyinequilibrium.SteelSheet.Athinsteelpanelusedinlieuofstructuralsheathingforwallbracingapplications.Strap.Flatorcoiledsheetsteelmaterialtypicallyusedforbracingandblocking,whichtransfersloads,bytensionand/orshear.StrapBracing.Steelstraps,applieddiagonallytoformaverticaltrussaspartofthelateralforceresistingsystem.StrengthDesign.Alsoknownasloadandresistancefactordesign,anoutdatedtermusedinsomereferencedocuments.[USAandMexico]StructuralComponent.Member,connector,connectingelementorassemblage.StructuralMember.Amemberthatresistsdesignloads[factoredloads]asrequiredbytheapplicablebuildingcode,exceptwhendefinedasanonstructuralmember.StructuralSheathing.Thecoveringuseddirectlyoverstructuralmembersthatiscapableofdistributingloads,bracingmembers,andgenerallystrengtheningtheassembly.Stud.Averticalframingmemberinawallsystemorassembly.Track.Aframingmemberconsistingofonlyaivebandtwo(2)flanges.Trackwebdepthmeasurementsaretakentotheinsideoftheflanges.Truss.Acoplanarsystemofstructuralmembersjoinedtogetherattheirends,usuallytoconstructaseriesoftrianglesthatformastablebeam-likeframework.TrussDesignEngineer.Personwhoislicensedtopracticeengineeringasdefinedbythelegalrequirementsofthejurisdictioninwhichthebuildingistobeconstructedandwhosupervisesthepreparationofthetrussdesigndrawings.TrussDesigner.Personresponsibleforthepreparationofthetrussdesigndrawings.TrussDesignDrawing.Written,graphicandpictorialdepictionofanindividualtruss.TrussManufacturer.Anindividualororganizationengagedinthemanufacturingofsite-builtorin-planttrusses.TrussMember.Achordmemberorwebmemberofatruss.TypeIBracedWallPanel.TypeIbracedwallpanelsaresheathedforthefullheightofthewallwithwoodstructuralsheathingpanelsorsteelsheetononeside,havenoopenings,andhavecontinuoussheathingbetweenhold-downanchors.TypeIShearWall.Walldesignedtoresistin-planelateralforcesthatisfullysheathedandthatisprovidedwithhold-downanchorsateachendofthewallsegment.TypeIshearwallsareonlypermittedtohaveopeningswheredetailingforforcetransferaroundtheopeningsisprovided.TypeIIBracedWall.TypeIIbracedwallsarefullysheathedforthefullheightofthewallwithwoodstructuralsheathingpanelsorsteelsheetononeside,andarepermittedtohaveopeningsbetweenhold-downanchors.TypeIIShearWall.Walldesignedtoresistin-planelateralforcesthatissheathedwithwoodstructuralpanelsorsheetsteelthatcontainsopenings,butwhichhasnotbeenspecificallydesignedanddetailedforforcetransferaroundwallopenings.Hold-downanchorsforTypeIIshearwallsareonlyrequiredattheendsofthewall.TypeIIShearWallSegment.Sectionofshearwall(withinaTypeIIshearwall)withfull-heightsheathing(i.e.,withnoopenings)andwhichmeetsspecificaspectratiolimits.Web.Thatportionofaframingmemberthatconnectstheflanges.

CoatingClassificationCoatingDesignatorMinimumCoatingRequirementsZincCoatedoz/ft(g/m)ZincIronoz/ft(g/m)55%Al-Zincoz/ft(g/m)Zinc-5%oz/ft(g/m)MetallicCoatedCP60G60[Z180]A60[ZF180]AZ50[AZM150]CF30[ZGF90]CP90G90[Z275]NotApplicableAZ50[AZM150]CF45[ZGF135]PaintedMetallicPMThemetalliccoatedsubstrateshallmeettherequirementsofmetalliccoated.Inaddition,thepaintfilmshallhaveaminimumthicknessof0.5milperside(primerplustopcoat)withaminimumprimerthicknessof0.1milperside.ENorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012Edition

7

WefcMember.Astructuralmemberinatrussthatisconnectedtothetopandbottomchords,butisnotachordmember.WindExposure.Windexposureinaccordancewiththeapplicablebuildingcode.YieldStrength.StressatwhichamaterialexhibitsaspecifiedlimitingdeviationfromtheproportionalityofstresstostrainasdefinedbyASTM.Z-Shape.Apoint-symmetricornon-symmetricsectionthatisusedasachordmemberinatruss.

A3Material

Structuralmembersutilizedincold-formedsteelframedconstructionshallbecold-formedtoshapefromsheetsteelcomplyingwiththerequirementsofASTMA1003/A1003M,subjecttothefollowinglimitations:(a)TypeH(highductility):Nolimitations.(b)TypeL(lowductility):Limitedtopurlins,girtsandcurtainwallstuds.Additionalcountry-specificlimitationsforcurtainwallstudsareprovidedinSectionA2.3.5ofAISISlOO[CSAS136]AppendixAorB,asapplicable.ForCanada:Alternatively,structuralmembersarepermittedtobecold-formedtoshapefromsheetsteelcomplyingwiththerequirementsofASTMA653/A653MTypeSSorASTMA792/A792MTypeSS.A4CorrosionProtectionA4.1Structuralmembersutilizedincold-formedsteelframedconstructionshallhaveaprotectivecoatingasspecifiedinTableA4-1.TableA4-1CoatingDesignations

Zinc-coatedsteelsheetasdescribedinASTMA653/A653M.BZinc-ironalloy-coatedsteelsheetasdescribedinASTMA653/A653M.55%aluminum-zincalloy-coatedsteelsheetasdescribedinASTMA792/A792M.DZinc-5%aluminumalloy-coatedsteelsheetasdescribedinASTMA875/A875M.EInaccordancewiththerequirementsofASTMA1003/A1003M.ForCanada:Structuralmembersutilizedincold-formedsteelframedconstructionshallhaveametalliccoatingofG60[Z180]complyingwiththerequirementsofASTMA653/A653MorAZ50[AZM150]complyingwiththerequirementsofASTMA792/A792M.

A4.2Additionalcorrosionprotectionshallnotberequiredonedgesofmetallic-coatedsteelframingmembers,shoporfieldcut,punchedordrilled.A4.3Unlessadditionalcorrosionprotectionisprovided,framingmembersshallbelocatedwithinthebuildingenvelopeandshieldedfromdirectcontactwithmoisturefromthegroundortheoutdoorclimate.

8

AISIS200-12

A4.4Dissimilarmetalsshallnotbeusedindirectcontactwithcold-formedsteelframingmembersunlessapprovedforthatapplication.A4.5Cold-formedsteelframingmembersshallnotbeembeddedinconcreteunlessapprovedforthatapplication.A4.6Fastenersshallhaveacorrosionresistanttreatment,orbemanufacturedfrommaterialnotsusceptibletocorrosion.A5Products

A5.1BaseSteelThickness

Thematerialthicknessofframingmembers,intheirend-use,shallmeetorexceedtheminimumbasesteelthicknessvaluesgiveninanapproveddesignorapprovedproductstandard,suchasAISIS201.Innocaseshalltheminimumbasesteelthicknessbelessthan95%ofthedesignthickness.A5.2MinimumFlangeWidthForC-shapemembersintendedtoreceivesheathing,theminimum/Zangewidthshallbe1-1/4inch(31.8mm).Fortrack,theminimumangewidthshallbe3/4inch(19.1mm).A5.3ProductDesignatorReferencestostructuralmembersshalluseafour-partproductdesignatorthatidentifiesthesize(bothwebdepthandflangewidth),style,andthickness.Thestandarddesignatorasdescribed(i.e.basedonU.S.Customaryunits)shallbeusedforeitherU.S.CustomaryorSIMetricunits.Theproductdesignatorshallconsistofthefollowingsequentialcodes:Athreeorfour-digitnumeralindicatingmemberivebdepthin1/100inch.Aletterindicating:S=StudorjoistframingmemberwhichhaslipsT=TracksectionU=ChannelorstudframingsectionwhichdoesnothavelipsF=FurringchannelsL=AngleorL-headerAthree-digitnumeralindicating/Zangewidthin1/100inch,followedbyadash.Atwo-orthree-digitnumeralindicatingdesignationthickness.Whenspecifyingmaterialforuseinstructuralapplications,thematerialgradeusedindesignshallbeidentifiedonthecontractdocumentsandwhenorderingthematerial.A5.4ManufacturingTolerancesStructuralmembersutilizedincold-formedsteelframedconstructionshallcomplywiththemanufacturingtoleranceslistedinTableA5-1.

DimensionItemCheckedStuds,in.(mm)Tracks,in.(mm)ALength+3/32(2.38)+1/2(12.7)-3/32(2.38)-1/4(6.35)B2WebDepth+1/32(0.79)+1/32(0.79)-1/32(0.79)+1/8(3.18)CFlare+1/16(1.59)+0(0)Overbend-1/16(1.59)-3/32(2.38)DHoleCenterWidth+1/16(1.59)NA-1/16(1.59)NAEHoleCenterLength+1/4(6.35)NA-1/4(6.35)NAFCrown+1/16(1.59)+1/16(1.59)-1/16(1.59)-1/16(1.59)G3Camber1/8per10ft(3.13per3m)1/32perft(2.60perm)1/2max(12.7)H3Bow1/8per10ft(3.13per3m)1/32perft(2.60perm)1/2max(12.7)1Twist1/32perft(2.60perm)1/32perft(2.60perm)1/2max(12.7)1/2max(12.7)NorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012Edition

9

TableA5-1ManufacturingTolerancesforStructuralMembers

1Allmeasurementsshallbetakennotlessthan1ft(305mm)fromtheend.2Outsidedimensionforstud;insidefortrack.31/8inchper10feetrepresentsL/960maximumforoverallcamberandbow.Thus,a20-footlongmemberwouldhave1/4-inchpermissiblemaximum;a5-footlongmemberwouldhave1/16-inchpermissiblemaximum.

FigureA5-1ManufacturingTolerancesforStructuralMembers

10

AISIS200-12

A5.5ProductIdentification

Framingmembersusedincold-formedsteelframedconstructionshallbeidentifiedinaccordancewiththerequirementsofthissection.A5.5.1IdentificationofGroupsofLikeIVIembersGroupsoflikemembersshallbemarkedwithalabel,oratagattachedthereto.Markingshallincludetheroll-former'sidentification(name,logo,orinitials),length,quantity,androll-former'smemberdesignatorincludingmemberdepth,flangesize,andminimumsteelthicknessinmilsorinchesexclusiveofprotectivecoating.A5.5.2IdentificationofIndividualFramingIVIembersInadditiontothemarkingreferencedinA5.5.1,individualframingmembersshallhavealegiblelabel,stencil,orembossment,atamaximumdistanceof96in.(2440mm)oncenter,onthemember,withthefollowingminimuminformation:(1)Theroll-former'sidentification(thatis,name,logo,orinitials).(2)Theminimumsteelthickness,inmilsorinches,exclusiveofprotectivecoatings.(3)Theminimumyieldstrengthinkippersquareinch(megapascals).(4)TheappropriateprotectivecoatingdesignatorinaccordancewithSectionA4.ForCanada:InadditiontothemarkingreferencedinA5.5.1,individualframingmembersshallhavealegiblelabel,stencil,orembossment,atamaximumdistanceof96in.(2440mm)oncentre,onthemember,withthefollowingminimuminformation:(1)Themanufacturer'sidentification(name,logo,orinitials);and(2)Theminimumsteelthickness(inmils,inchesormillimeters)exclusiveofprotectivecoatings.A6ReferencedDocuments

Thefollowingdocumentsorportionsthereofarereferencedwithinthisstandardandshallbeconsideredaspartoftherequirementsofthisdocument.1.AmericanIronandSteelInstitute(AISI),25MassachusettsAvenue,NW,Suite800,Washington,DC20001:AISISI00-12,NorthAmericanSpecificationfortheDesignofCold-FormedSteelStructuralMembersAISIS201-12,NorthAmericanStandardforCold-FormedSteelFraming-ProductData2.ASTMInternational,100BarrHarborDrive,WestConshohocken,PA19428-2959:ASTMA653/A653M-11,SpecificationforSteelSheet,Zinc-Coated(Galvanized)orZinc-IronAlloy-Coated(Galvannealed)bytheHot-DipProcessASTMA792/A792M-10,SpecificationforSteelSheet,55%Aluminum-ZincAlloy-CoatedbytheHot-DipProcessASTMA875/A875M-10,SpecificationforSteelSheet,Zinc-5%AluminumAlloy-CoatedbytheHot-DipProcessASTMA1003/A1003M-11,StandardSpecificationforSheetSteel,Carbon,MetallicandNon-MetallicCoatedforCold-FormedFramingMembersASTMC954-10,StandardSpecificationforSteelDrillScrewsfortheApplicationofGypsumPanelProductsorMetalPlasterBasestoSteelStudsFrom0.033in.(0.84mm)to0.112in.(2.84mm)inThickness


11

ASTMC1002-07,SteelSelf-PiercingTappingScrewsfortheApplicationofGypsumPanelProductsorMetalPlasterBasestoWoodStudsorSteelStudsASTM,C1513-10,StandardSpecificationforSteelTappingScrewsforCold-FormedSteelFramingConnections3.AmericanWeldingSociety,8669DoralBoulevard,Suite130,Doral,FL33166:AWSD1.3,StructuralWeldingCode-SheetSteel,1998Edition4.CanadianStandardsAssociation,5060SpectrumWay,Mississauga,Ontario,CanadaL4W5N6:CAN/CSA-S136-12,NorthAmericanSpecificationfortheDesignofCold-FormedSteelStructuralMembers

12

AISIS200-12

B.MEMBERDESIGN

B1Members

FramingmembersshallbedesignedinaccordancewithAISISlOO[CSAS136].B2MemberCondition

Framingmembersshallbeasspecifiedbyanapproveddesignorapproveddesignstandard.Themembersshallbeingoodcondition.Damagedmembersshallbereplacedorrepairedinaccordancewiththeapproveddesignorapproveddesignstandard.B2.1WebHoles

Holesinwebsofframingmembersshallbeinconformancewithanapproveddesign,AISISlOO[CSAS136],oranapproveddesignstandard.Webswithholesnotconformingtotheaboveshallbereinforcedorpatchedinaccordancewithanapproveddesignorapproveddesignstandard.

B2.2Cutting,PatchingandSplicing

B2.2.1CuttingandPatchingAllcuttingofframingmembersshallbedonebysawing,abrasivecutting,shearing,plasmacuttingorotherapprovedmethods.Cuttingornotchingofstructuralmembers,includingflangesandlipsoijoists,studs,headers,rafters,andceilingjoists,orthepatchingofthosecutsshallnotbepermittedwithoutanapproveddesignorinaccordancewithanapproveddesignstandard.B2.2.2SplicingSplicingofjoists,studsandotherstructuralmembersshallnotbeperformedwithoutanapprovedsplicedesignorinaccordancewithanapproveddesignstandard.


13

C.INSTALLATION

CIIn-lineFramingEachjoist,rafter,truss,andstructuralwallstud(aboveorbeneath)shallbealignedverticallyaccordingtothelimitsdepictedinFigureCl-1.Thealignmenttoleranceisnotrequiredwhenastructuralloaddistributionmemberisspecifiedinaccordancewithanapproveddesignorapproveddesignstandard.

HORIZONTAL/FRAMINGMEMBER

HORIZONTALFRAMING

MEMBERBEARINGSTIFFENERBEARINGSTIFFENERTRACKTRACKSTUDSTUD

ttSTUD

BEARINGSTIFFENER

HORIZONTALFRAMINGc

HORIZONTALFRAMING

HORIZONTALFRAMING

MEMBER

3/4"(19mm)MAX.'

1

DC

IIiJ

MEMBER

I3/4"(19mm)MAX.

1

MEMBER

34"(19mm)MAX.

MS-(3mm)MAX.FROMWEBOFHORIZONTALFRAMING

VERTICALFRAMINGMEMBER


MEMBERTOEDGEOFVERTICALFRAMINGMEMBER


FigureCl-1In-LineFramingC2InstallationTolerances

C2.1Foundation

Thefoundationshallbelevelandfreefromdefectsbeneathloadbearingwalls.Ifthefoundationisnotlevel,provisionsshallbemadetoprovideauniformbearingsurfacewithamaximum1/4-inch(6.4mm)gapbetweenthebottomtrackorrimtrackandthefoundation.Thisshallbeaccomplishedthroughtheuseofloadbearingshimsorgroutprovidedbetweentheundersideofthewallbottomtrackorrimtrackandthetopofthefoundationwallorslabatstudorjoistlocations.C2.2GroundContact

Framingshallnotbeindirectcontactwiththegroundunlessspecifiedbyanapproveddesign.Framingnotindirectcontactwiththegroundshallbeinstalledataheightabovethegroundinaccordancewiththeapplicablebuildingcode.

14

AISIS200-12

C2.3Floors

C2.3.1PlumbnessandLevelness

Floorjoistsandfloortrussesshallbeinstalledplumbandlevel,exceptwheredesignedasslopingmembers.C2.3.2FloorSpanCapacityFloorjoistandfloortrussspacingshallnotexceedthespancapacityofthefloorsheathingmaterial.C2.3.3AlignmentFloorjoistsandfloortrussesshallcomplywiththealignmentrequirementsofSectionCI.

C2.3.4BearingWidthFloorjoistsandfloortrussesshallbeinstalledwithfullbearingoverthewidthofthebearingwallbeneath,aminimum1-1/2inch(38.1mm)bearingend,orinaccordancewithanapproveddesignorapproveddesignstandard.C2.3.5WebSeparationFloorjoistwebsshallnotbeindirectcontactwithrimtrackwebs.C2.4Walls

C2.4.1Straightness,PlumbnessandLevelnessWallstudsshallbeinstalledplumb,exceptwheredesignedasslopingmembers.Walltrackmembersshallbeinstalledlevelexceptwheredesignedasslopingmembers.C2.4.2SheathingSpanCapacityWallstudspacingshallnotexceedthespancapacityofthesheathingmaterial.C2.4.3AlignmentStructuralwallstudsshallcomplywiththealignmentrequirementsofSectionCIforin-lineframing.C2.4.4EndBearingEndsofaxialloadbearingwallstudsshallhavesquareendcutsandshallbeseatedtightagainstthetrackswithamaximumgaptoleranceof1/8inch(3.18mm)betweentheendofwallframingmemberandthewebofthetrack.Forthicknessesofthestudortrackgreaterthan54mil(0.054inches(1.37mm)),specialconsiderationshallbegiventotheendgapandthemaximumendgapshallbespecifiedbytheBuildingDesigner.C2.5RoofsandCeilings

C2.5.1PlumbnessandLevelnessRoofandceilingframingmembersshallbeinstalledplumbandlevel,exceptwheredesignedasslopingmembers.


15

C2.5.2SheathingSpanCapacityThespacingofroofandceilingframingmembersshallnotexceedthespancapacityoftheceilingorroofsheathingmaterial.C2.5.3AlignmentRoofandceilingframingmembersshallcomplywiththealignmentrequirementsofSectionCIforin-lineframing.C2.5.4BearingCeilingjoistsandrooftrussesshallbeinstalledwithfullbearingoverthewidthofthebearingwallbeneath,oraminimum1-1/2inch(38.1mm)bearingendcondition,orinaccordancewithanapproveddesignorapproveddesignstandard.

16

AISIS200-12

D.CONNECTIONS

D1ScrewConnections

Dl.lSteel-to-SteelScrews

Screwfastenersforsteel-to-steelconnectionsshallbeincompliancewithASTMC1513oranapproveddesignorapproveddesignstandard.Useofalarger-than-specifiedscrewsizeispermitted,providingthatthedesignandinstallationareinaccordancewiththeminimumspacingandedgedistancerequirements.D1.2SheathingScrewsScrewfastenersforstructuralsheathingtosteelconnectionsshallbeincompliancewithASTMC1513oranapproveddesignorapproveddesignstandard.D1.3Installation

Screwfastenersshallextendthroughthesteelconnectionaminimumofthree(3)exposedthreads.Screwfastenersshallpenetrateindividualcomponentsofconnectionswithoutcausingpermanentseparationbetweencomponents.D1.4StrippedScrewsStrippedscrewfastenersindirecttensionshallbeconsideredineffective.Strippedscrewfastenersinshearshallonlybeconsideredeffectivewhenthenumberofstrippedscrewfastenersconsideredeffectivedoesnotexceedtwenty-fivepercent(25%)ofthetotalnumberofscrewfastenersconsideredeffectiveintheconnection.

D1.5SpacingandEdgeDistanceForscrewfastenersinsteel-to-steelconnectionstobeconsideredfullyeffective,theminimumcenter-to-centerspacingandedgedistanceshallbethree(3)timesthenominaldiameter,exceptwheretheedgeisparalleltothedirectionoftheappliedforce,theminimumedgedistanceofscrewfastenersshallbe1.5timesthenominaldiameter.Wheretheminimumcenter-to-centerspacingistwo(2)timesthenominaldiameter,screwfastenersshallbeconsidered80percenteffective.D1.6GypsumBoardGypsumboardshallbeattachedtocold-formedsteelframinginaccordancewiththeapplicablebuildingcodeoranapproveddesignstandard.ScrewfastenersforgypsumboardtosteelconnectionsshallbeincompliancewithASTMC954,ASTMC1002,orASTMC1513,asapplicable,withabugleheadstyle.D2WeldedConnections

WeldedconnectionsshallbeinaccordancewithAISISlOO[CSAS136]andAWSD1.3.ThedesigncapacityofweldsshallbeinaccordancewithAISISlOO[CSAS136].Weldedareasshallbetreatedwithanapprovedtreatmenttoretainthecorrosionresistanceoftheweldedarea.


17

D3OtherConnections

D3.1Bolts

Boltedcold-formedsteelconnectionsshallbedesignedandinstalledinaccordancewithAISISlOO[CSAS136].D3.2OtherConnectors

Othertypesofconnections(e.g.PneumaticallyDrivenFasteners,Powder-ActuatedFasteners,RivetFastenersandClinchJoining)shallbedesigned,fabricatedandinstalledinaccordancewiththedesignrequirementsassetforthbyanapproveddesignorapproveddesignstandard,andthefastenermanufacturer'srequirements.D3.3ConnectiontoOtherIVIaterials

Bolts,nails,anchorboltsorotherfastenersusedtoconnectcold-formedsteelframingtowood,masonry,concreteorothersteelcomponentsshallbedesignedandinstalledinaccordancewiththeapplicablebuildingcode,anapproveddesignorapproveddesignstandard.

18

AISIS200-12

E.MISCELLANEOUS

ElUtilities

El.lHoles

HolesshallcomplywiththerequirementsspecifiedinSectionB2.1.Penetrationsoffloor,wallandceiling/roofassemblieswhicharerequiredtohaveafireresistanceratingshallbeprotectedinaccordancewiththeapplicablebuildingcodeorinaccordancewiththerequirementsasstipulatedbytheauthorityhavingjurisdiction.E1.2PlumbingAllpipingshallbeprovidedwithanisolativenon-corrosivesystemtopreventgalvanicactionorabrasionbetweenframingmembersandpiping.E1.3Electrical

Wiringnotenclosedinmetalconduitshallbeseparatedfromtheframingmembersbynon-conductivenon-corrosivegrommetsorbyotherapprovedmeans.E2Insulation

E2.1MineralFiberInsulation

Mineralfiberinsulation(e.g.rockwool,glassfiber,etc.)forinstallationwithincavitiesofframingmembersshallbefull-widthtypeinsulationandshallbeinstalledinaccordancewiththerequirementsassetforthbytheapplicablebuildingcodeandinsulationmanufacturer.CompressionoftheinsulationshallbepermittedtooccurattheopensideoftheC-shapedframingmember.E2.2OtherInsulation

Othertypesofinsulation(e.g.foams,loosefill,etc.)forinstallationwithincavitiesofframingmembersshallbeinstalledinaccordancewiththeapplicablebuildingcodeandinsulationmanufacturer'srequirements.Thewidthofinsulationshallbedimensionallycompatiblewiththecold-formedsteelframing.

felllns?i?u~P**!CrSsteel

AISISTANDARD

Commentaryonthe

NorthAmericanStandardfo

Cold-FormedSteelFraming

GeneralProvisions

2012Edition

AISIS200-12-C

DISCLAIMERThematerialcontainedhereinhasbeendevelopedbytheAmericanIronandSteelInstitute(AISI)CommitteeonFramingStandards.TheCommitteehasmadeadiligentefforttopresentaccurate,reliable,andusefulinformationoncold-formedsteelframingdesignandinstallation.TheCommitteeacknowledgesandisgratefulforthecontributionsofthenumerousresearchers,engineers,andotherswhohavecontributedtothebodyofknowledgeonthesubject.SpecificreferencesareincludedinthisCommentary.Withanticipatedimprovementsinunderstandingofthebehaviorofcold-formedsteelframingandthecontinuingdevelopmentofnewtechnology,thismaterialwillbecomedated.ItisanticipatedthatAISIwillpublishupdatesofthismaterialasnewinformationbecomesavailable,butthiscannotbeguaranteed.Thematerialssetforthhereinareforgeneralpurposesonly.Theyarenotasubstituteforcompetentprofessionaladvice.Applicationofthisinformationtoaspecificprojectshouldbereviewedbyadesignprofessional.Indeed,inmanyjurisdictions,suchreviewisrequiredbylaw.Anyonemakinguseoftheinformationsetforthhereindoessoattheirownriskandassumesanyandallliabilityarisingtherefrom.

1stPrinting-April2013

CopyrightAmericanIronandSteelInstitute2012

CommentaryontheNorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012EditionIII

PREFACEThisCommentaryisintendedtofacilitatetheuseandprovideanunderstandingofthebackgroundofAISIS200,theNorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions.TheCommentaryillustratesthesubstanceandlimitationsofthevariousprovisionsofthestandard.IntheCommentary,sections,equations,figures,andtablesareidentifiedbythesamenotationasusedinthestandard.WordsthatareitalicizedaredefinedinAISIS200.TermsincludedinsquarebracketsarespecifictoLimitStatesDesignterminology.

AISIS200-12-C

ThisPageisIntentionallyLeftBlank.

CommentaryontheNorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012Editionv

TABLEOFCONTENTSCOMMENTARYONTHENORTHAMERICANSTANDARDFORCOLD-FORMEDSTEELFRAMING-GENERALPROVSIONS

DISCLAIMERiiPREFACEiiiA.GENERAL1A1Scope1A2Definitions1A3Material3A4CorrosionProtection3A5Products4A5.2MinimumFlangeWidth5B.MEMBERDESIGN6B1Members6B2MemberCondition6B2.1WebHoles6B2.2Cutting,Patching,andSplicing6C.INSTALLATION7CIIn-LineFraming7C2InstallationTolerances7C2.1Foundations7C2.2GroundContact7C2.3Floors7C2.4Walls8C2.5RoofsandCeilings9D.CONNECTIONS10D1ScrewConnections10Dl.lSteel-to-SteelScrews10D1.4StrippedScrews12D1.5SpacingandEdgeDistance12D1.6GypsumBoard12D2WeldedConnections12D3OtherConnections12E.MISCELLANEOUS13ElUtilities13El.lHoles13El.2Plumbing13El.3Electrical13E2Insulation13REFERENCES15

AISIS200-12-C

ThisPageisIntentionallyLeftBlank.

CommentaryontheNorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012Edition

1

COMMENTARYONTHENORTHAMERICANSTANDARDFORCOLD-FORMEDSTEELFRAMING-GENERALPROVISONS

A.GENERAL

A1ScopeAISIS200(AISI,2012b)appliestothedesignandinstallationofstructuralmembersutilizedincold-formedsteelframingapplicationsforloadcarryingpurposesinbuildings.Althoughthestandardaddressestheapplicationofframingmembershavingbasesteelthicknessnotgreaterthan118mils(0.1180inches)(2.997mm),thestandarddoesnotprecludetheuseofothercold-formedsteelmembers,assemblies,structures,ordesignswhentheydemonstrateequivalentperformancefortheintendedusetothosespecifiedinthestandard.ThestandardisintendedtoserveasasupplementtoAISISlOO[CSAS136],(AISI,2012a;CSA,2012).In2011,designprovisionsrelatedtononstructuralmembersweremovedtoAISIS220,NorthAmericanStandardforCold-FormedSteelFraming-NonstructuralMembers(AISI,2011).However,useofthemorestringentrequirementsforstructuralmembersthatareinAISIS200fornonstructuralmembersshouldbepermitted,sincetheseshoulddemonstrateequivalentperformancefortheintendedusetothosespecifiedinAISIS220.Alsoin2011,thelowerlimitonbasesteelthicknesswasdeemedunnecessaryandwaseliminated.A2Definitions

Codesandstandardsbytheirnaturearetechnical,andassuchspecificwordsandphrasescanchangetheintentoftheprovisionsifnotproperlydefined.Asaresult,itisnecessarytoestablishacommonplatformbyclearlystatingthemeaningofspecifictermsforthepurposeofthisstandardandotherstandardsthatreferencethisstandard.Inthestandard,blockingisdefinedtotransfershearforceortostabilizemembers.ThefollowingfiguresC-A2-1andCA2-2showexamplesofhowtrackorstudmembersareusedasblockinginvariousassemblies.

2

FigureC-A2-1,ApplicationofStudTrackBlocking

FigureC-A2-2,ApplicationofJoistBlocking

AISIS200-12-C


3

A3Material

ThesheetsteelapprovedforusewiththisstandardforstructuralmembersmustcomplywithASTMA1003/1003M(ASTM,2011a).ASTMA1003/1003Mcoversthechemical,mechanicalandcoatingrequirementsforsteelsheetusedinthemanufactureofcold-formedsteelframingmemberssuchasstuds,joists,andtrack.ASTMA1003/1003Misastandardthatwasdevelopedinordertoincorporaterequirementsformetallic-coated,paintedmetallic-coated,orpaintednonmetallic-coatedsteelsheetusedforcold-formedsteelframingmembersintoasinglestandard.MechanicalpropertiesdefinedinASTMA1003/A1003Mareminimumrequirements.Forexample,theminimumyieldstrengthofTypeHorL33[NS230]steelis33ksi[230MPa];materialwithhigheryieldstrengthispermitted,but33ksi[230MPa]isthedesignyieldstrength.Additionally,accordingtotheASTMA1003/1003MStandard,StructuralGradeTypesHandLsteelareintendedforstructuralmembersandNon-StructuralGradeTypeNSsteelisintendedfornonstructuralmembers.Itisnotedthatadditionalcountry-specificlimitationsforcurtainwallstudsareprovidedinAISISlOO[CSAS136](AISI,2012a;CSA,2012),A2.3.5,AppendixAorB.ClarificationsoftheuseoftypesH,L,andNSsteelswereprovidedin2012aspartofanexercisetosynchronizeallcodesandspecifications.WiththedevelopmentofAISIS220in2011,TypeNSofASTMA1003/A1003Mthatisapplicablefornonstructuralmemberswasremovedfromthisstandard.

A4CorrosionProtection

In2012,aspartofanexercisetosynchronizeallrelevantcodesandspecifications,theprovisionsofSectionA4.1wereconsolidatedfromAISIS201SectionB3,ASTMC645(ASTM,2011b)andASTMC955(ASTM,2011c).TheminimumcoatingdesignationslistedinTableA4-1ofthestandardassumenormalexposureandconstructionpractices.Othertypesofcoatingsthatprovideequalorbettercorrosionprotectionmayalsobeacceptable.Whenmoresevereexposureconditionsareprobable,considerationshouldbegiventospecifyingheaviercoatingweight[mass].Theminimumcoatingspecifiedbythisstandardassumesnormalexposureconditionsthatarebestdefinedashavingtheframingmembersenclosedwithinabuildingenvelopeorwallassemblywithinacontrolledenvironment.Whenmoresevereexposureconditionsareprobable,suchasindustrialatmospheresandmarineatmospheres,considerationshouldbegiventospecifyingaheaviercoating.Coatingisspecifiedbyweightormass.Thisstandarddoesnotrequiretheedgesofmetallic-coatedcold-formedsteelframingmembers,shoporfieldcutinaccordancewithSectionB2.2.1,punchedordrilled,tobetouchedupwithzinc-richpaint,whichisabletogalvanicallyprotectsteel.Whenbasesteelisexposed,suchasatacutorscratch,thesteeliscathodicallyprotectedbythesacrificialcorrosionofthezinccoating,becausezincismoreelectronegative(morereactive)thansteelinthegalvanicseries.Azinccoatingwillnotbeundercutbecausethesteelcannotcorrodeadjacenttothezinccoating.Therefore,anyexposureoftheunderlyingsteelatanedgeorscratchwillnotresultincorrosionofthesteelawayfromtheedgeorscratchandthuswillnotaffecttheperformanceofthecoatingorthesteelstructure(CFSEI,2007a).ItisnotedthatASTMA1004/A1004M(ASTM,2009)coversproceduresforestablishingtheacceptabilityofsteelsheetforuseascold-formedsteelframingmembers.Thispracticeistobeusedtoassessthecorrosion-resistanceofdifferentcoatingsonsteelsheetinalaboratorytest.Itisnotintendedtobeusedasanapplicationperformancestandardforthecold-formedsteelframing,but

4

AISIS200-12-C

istobeusedtoevaluatecoatingsunderconsiderationforadditiontoASTMA1003/A1003M(ASTM,2011a).Directcontactwithdissimilarmetals(e.g.copper,brass,etc.)shouldbeavoidedinordertopreventunwantedgalvanicactionfromoccurring.Methodsforpreventingthecontactfromoccurringmaybethroughtheuseofnon-conductivenon-corrosivegrommetsativebpenetrationsorthroughtheuseofnon-metallicbrackets(a.k.a.isolators)fastenedtoholdthedissimilarmetalbuildingproducts(e.g.piping)awayfromthecold-formedsteelframing.In2006,achangewasmadetothisstandardallowingtheuseofdissimilarmetalsincontactwithcold-formedsteelframingprovidedthespecificapplicationisapproved.Itwasrecognizedthatdissimilarmetalsincontactmightnotalwaysbeaproblem.Forexample,therearenogalvanicconcernswherethereisnomoisture.AspecialcaseofdissimilarmetalsoccursinCanadawhere,forcertainclimaticconditionsandbuildingheights,theuseofstainlesssteelbricktiesisrequired.Whenthesetiesareconnectedtosteelstudbackup,contactbetweendissimilarmetalscanoccur.Forguidanceonthisdissimilarmetalsissue,refertotheCanadianStandard,CAN/CSA-A370-04,ConnectorsforMasonry(CSA,2009).Whenthereisdirectcontactofcold-formedsteelframingwithpressure-treatedwood,thetreatedwood,cold-formedsteelframing,connectorand/orfastenermanufacturersshouldbecontactedforrecommendations.Methodsthatshouldbeconsideredmayincludespecifyingalesscorrosivepressuretreatment(sodiumborate,organicpreservativesystems,etc.),isolatingthecold-formedsteelandwoodcomponents,orchangingdetailstoavoiduseofpressure-treatedwoodaltogether.Designprofessionalsshouldtakeintoaccountboththeinitialcontactwithwetordampbuildingmaterials,aswellasthepotentialforthosematerialstoabsorbwaterduringthebuilding'slife,asbothcircumstancesmayacceleratecorrosion.In2007,theCold-FormedSteelEngineersInstituteupdatedthe2004AISIdocument"DurabilityofCold-FormedSteelFramingMembers"(CFSEI,2007a)togiveengineers,architects,buildersandhomeownersabetterunderstandingofhowgalvanizing(zincandzinc-alloycoatings)provideslong-termcorrosionprotectiontocold-formedsteelframingmembers.AdditionalinformationcanbeobtainedfromtheAmericanGalvanizersAssociationpublication"HotDipGalvanizingForCorrosionProtection-ASpecifier'sGuide"(AGA,2006)andtheCold-FormedSteelEngineersInstitute'spublication"CorrosionProtectionforCold-FormedSteelFraminginCoastalAreas"(CFSEI,2007b).In2011,corrosionprotectionrequirementsfornonstructuralmembersweremovedtoAISIS220(AISI,2011).A5Products

AISISlOO[CSAS136],(AISI,2012a;CSA,2012)permitstheminimumdeliveredbasesteelthickness(exclusiveofanycoatings)ofacold-formedsteelmembertobe95%ofthedesignthickness.ThisstandardthereforespecifiestheminimumbasesteelthicknessthatcomplieswithAISISlOO[CSAS136].Thethicknessdesignationsareconsistentwithstandardindustrypractice,aspublishedinAISIS201(AISI,2012c).Itisrecommendedthatthicknessmeasurementsbetakeninthemiddleoftheflatoftheflangeorivebofthecross-section.AISIS201hasadoptedastandarddesignatorsystemforidentifyingcold-formedsteelframingmembers.Theintentforusingastandarddesignatorsystemistoovercomethevarieddesignatorsthatareproducedbyeachindividualmanufacturer.Inaddition,thedesignatorisusedtoidentifynotonlyaspecificcold-formedsteelframingmember,butalsothesectionpropertiesofthatsamememberthroughtheuseofthemanufacturer'sproducttechnical

33for33mil(0.0329inch)(0.836mm)minimumthickness162for1.625inch(41.3mm)flangewidth"S"forstudorjoist350for3.50inch(89.9mm)webdepthCommentaryontheNorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012Edition

5

informationdocuments.Thefollowingpresentsanexampleofthestandarddesignatorforacold-formedsteelstud:350S162-33representsamemberwiththefollowing:350S162-33

In2012,aspartofanexercisetosynchronizeallrelevantcodesandspecifications,theminimumtolerancesforthemanufactureofstructuralmembersutilizedincold-formedsteelframingweremovedfromtheCommentarytotheStandardSectionA5.In2011,theminimumtolerancesforthemanufactureofnonstructuralmembersweremovedtoAISIS220(AISI,2011).Themanufacturingtolerancesforlength,ivebwidth,camber,bow,twist,etc.offramingmemberswereconsistentwithASTMC955(ASTM2011c)andASTMC645(ASTM,2011b).Toaidinshopandfieldverification,allframingmembersneedtocarryaproductidentificationtoindicateconformancewiththeminimumbasesteelthickness,coatingdesignation,minimumyieldstrength,andmanufacturer'sname.In2012,aspartofanexercisetosynchronizeallrelevantcodesandspecifications,theprovisionsofSectionA5.4ofthestandardwereconsolidatedfromAISIS201SectionC6,ASTMC645andASTMC955.In2012,colorcodingofindividualframingmembersorgroupsoflikememberswereremovedwithconsiderationthatthecolorcodingapproachmaycauseconfusionindifferentiatingbetweenstructuralandnonstructuralmembersofthesamethickness.Further,colorcodingisoptionalandthecriterion,ifneeded,existsinanon-mandatoryAppendixofASTMC645.

A5.2MinimumFlangeWidthIn2012,aspartofanexercisetosynchronizeallrelevantcodesandspecifications,theprovisionsofSectionA5.2wereconsolidatedfromASTMC645andASTMC955.TheminimumflangewidthforC-shapememberswasincludedinthestandardtoaccommodateabuttjointofsheathing.Theminimumflangewidthfortrackmemberswasincludedinthestandardtoaccommodateanedgejointofsheathing.

6

AISIS200-12-C

B.MEMBERDESIGN

B1Members

ThestrengthdeterminationsrequiredbythisstandardaretobeinaccordancewithAISISlOO[CSAS136](AISI,2012a;CSA,2012).FordesignguidanceontheapplicationofAISISlOO[CSAS136]totypicalcold-formedsteelconstructionrefertoDesignGuideforCold-FormedSteelFraming(AISI,2007)andCold-FormedSteelDesign(Yu,2010).B2MemberCondition

Toensurethatstructuralperformanceisincompliancewiththeengineereddesign,framingmembersmustnotbedamaged.Damageassessmentisnotwithinthepurviewofthisstandard.Thedesignprofessionalshouldbeconsultedwhendamagealtersthecross-sectiongeometryofaframingmemberbeyondthespecifiedtolerances.B2.1WebHoles

AISISlOO[CSAS136]stipulatesdesignrequirementsformemberswithstandardwebholes.Inthefield,these"webholes"mayalsobereferredtoas"punchouts","utilityholes","perforations"and"webpenetrations".Instructuralmembers,webholesaretypically1.5in.(38mm)widex4in.(102mm)longandarelocatedonthecenterlineofthewebdepth.Thewebholesaregenerallyspaced24in.(610mm)on-center.B2.2Cutting,Patching,andSplicingThisstandardplacesrestrictionsonacceptablemethodsforcuttingofframingmemberssothatcutedgesarenotexcessivelyroughorunevenandprotectivemetalliccoatingsarenotdamagedinareasawayfromcutedges.Shearingcold-formedsteelframingduringmanufacturing,fabricationandinstallationmaybeperformedinavarietyofways.Shearingmethodsincludebutarenotlimitedtothefollowing:Hydraulicshears,Hydraulicholepunches,Portablehydraulicshears,Hand-heldelectricshears,Aviationsnips,andPortableholepunches.Coping,cuttingornotchingofflangesandedgestijfenersisnotpermittedforstructuralmemberswithoutanapproveddesign.Forguidanceondesignforcopedmembersintrusses,refertoAISIS214(AISI,2012d).Structuralmembersmaybespliced;however,splicingofstudsandjoistsisnotacommonpracticeandisnotrecommended.Ifastructuralmemberrequiressplicing,thespliceconnectionmustbeinstalledinaccordancewithanapproveddesign.


7

C.INSTALLATION

CIIn-lineFramingIn-lineframingisthepreferredandmostcommonlyusedframingmethod.Theadvantageofin-lineframingisthatitprovidesadirectloadpathfortransferofforcesfromjoiststostuds.Thestandardstipulatesmaximumframingalignmenttominimizesecondarymomentsontheframingmembers.Theweakaxisbendingstrengthoftrackisminimalandthereforethetrackcannotfunctionasaloadtransfermember.Intheabsenceofin-lineframing,aloaddistributionmember,suchasastructuraltrack,mayberequiredforthisforcetransfer.Foracold-formedsteeljoistfloorsystem,thecapacityoftheinter-storyloadpathisdefinedbySectionC3.4ofAISISlOO[CSA136](AISI,2012a;CSA,2012)basedonwebcripplingofthejoistaloneorSectionC3.7ofAISISlOO[CSA136]whenabearingstiffenerisemployed.Industrypracticehasacceptedin-lineframingtomeanthatthejoist,rafter,trussandstructuralwallstudframingwouldbealignedsothatthecenterline(mid-width)iswithin%inch(19mm)ofthecenterline(mid-width)oftheloadbearingmembersbeneath.However,the%-inch(19-mm)allowableoffsetcreatesthepossibilityforamisalignmentintheloadpathfromanupperstoryloadbearingstudwall,throughajoistwithabearingstiffenerandontoaloadbearingstudorfoundationwallbelow.In2003,atotalof110end-andinterior-two-flangeloadingtestsofvariousfloorjoistassemblieswerecarriedoutattheUniversityofWaterloo(Fox,2003)todeterminetheeffectthatanoffsetloadinghasonthestrengthoftypicalfloors.ItwasconcludedthatanadditionallimitshouldbeplacedonthebearingstiffeneroffsettotheloadbearingmembersaboveorbeneathforcaseswherethebearingstiffenerisattachedtothebackofthejoistasdepictedinFigureCl-1inthestandard.Asanalternativetoin-lineframing,thestandardpermitstheuseofastructuralloaddistributionmemberthatisspecifiedinaccordancewithanapproveddesignorapproveddesignstandard.Asanaidtodesigners,strengthandstiffnesshavebeendeterminedexperimentallyforvariousloadbearingtoptrackassemblies(NAHB-RC,2003;Dawe,2005),includingstandardsteeltrack,deep-legsteeltrack,andsteeltrackwitha2xwoodtopplate.DesignguidanceforsomeofthetypicaltoptrackloaddistributionmembersisavailablefromtheCold-FormedSteelEngineersInstitute(CFSEI,2010a).C2InstallationTolerancesC2.1Foundations

Anunevenfoundationmaycauseproblems.ThespecifiedVi-in.(6.4-mm)gaphasbeendeemedacceptableindustrypractice.C2.2GroundContact

Tominimizethepotentialforcorrosion,caremustbetakentoavoiddirectcontactbetweenthecold-formedsteelframingandtheground.Inadditiontodirectcontact,itisimportanttominimizethepotentialforcorrosionresultingfromambientmoisture.Theapplicablebuildingcodeiscitedastheauthoritativedocumentthatwillprovideguidanceconcerningminimumseparationdistancesfromthegroundtotheframingmember,installationrequirementsformoisturebarriers,andthenecessaryventilationofthespace.C2.3Floors

Toavoidprematurefailureatasupportandtoachievein-lineframing,fullbearingofthe

8

AISIS200-12-C

joistonitssupportingwallisnecessary.Theintentofspecifyingthatthetrackandjoistwebsarenottobeindirectcontactwitheachotheristopreventfloorsfromcreatinganunwantednoise(e.g.squeaks).C2.4Walls

C2.4.1Straightness,PlumbnessandLevelnessWallstudsmustbeinstalledplumbtoavoidthepotentialforsecondarybendingmomentsinthemember.

C2.4.4EndBearingThestudmustbenestedandproperlyseatedintothetopandbottomtracktoprovideforadequatetransferofforcesandminimizeaxialdeflections.Eachflangeofthestudshouldalsobeattachedtothetrackstobracethetopandbottomofthestudagainstweakaxisandtorsionaldisplacements.Themaximumendgaptolerancespecifiedbythisstandardisbasedontraditionalindustrypractice.ThetolerancesspecifiedinstandardsectionC2.4.4areonlyforaxialloadbearingwalls,whichisdefinedinSection202oftheIBC(ICC,2012)asanymetalorwoodstudwallthatsupportsmorethan100poundsperlinearfoot(1459N/m)ofverticalloadinadditiontoitsownweight.Axialloadsinawallstudinexcessofthecapacityofthescrewconnectionbetweenthestudanditsseatingtrackswillbetransferredbetweenthestudandtrackinbearing.Inthissituation,ifastudisnotproperlyseated,relativemovementbetweenthestudandthetrackmayoccur,whichreducesorclosesanygapbetweentheendofthestudandthetrack.Todeterminetheinfluenceofthisrelativemovementbetweenthestudandthetrackontheserviceabilityofsheathedwallassemblies,atestingprogramwasconductedattheUniversityofMissouri-Rolla(Findlay,2005).TheUMRtestprogramonlyconsideredthestudandthetrackhavingthesamethickness.Forthinnerstudandtrackmaterials(0.054inches(1.37mm)orless),testingshowedthatrelativemovementbetweenthestudandthetrackwasaccommodatedthroughacombinationoftrackdeformationandscrewtilting.Inthesecases,theconnectionremainedintactandwascapableofresistingupliftforcesandpreventingstudweakaxisandtorsionaldisplacement.Forthickermaterials(greaterthan0.054inches),testingshowedthattherelativemovementbetweenthestudandthetrackcouldresultinshearfailureofthescrews.Inthesecases,testingindicatedasmallerendgaptolerance(e.g.,1/16inch(1.59mm))wouldbedesirabletolimitrelativemovementandpotentialscrewfailure.Inadditiontoasmallerendgaptolerancetoavoidpotentialscrewfailureintrackthickerthan0.054inches(1.37mm),asmallergaptolerancemayalsobedesirableformulti-storystructureswheretheaccumulationofgapclosuresmaybecomesignificant.Specialconsiderationsmayalsobedesirableforheavilyloadedcold-formedsteelstructuresandconditionssusceptibletodeflections.Onemethodtohelpachieveadequateendbearingandminimizeundesirablerelativemovementbetweenthestudandthetrackistospecifyasmaller1/16-in.(1.59-mm)maximumgap.Thisisarelativelysimplecriteriontoverify.However,the1/16-in.(1.59-mm)maximumgapisonoccasiondifficulttoachieve,particularlywith0.097in.(2.46mm)orthickertrack.Anothermethodtoachieveadequateendbearingistopre-compressthestudinsidethe


9

track.Thisisoftenaccomplishedwhenpanelizingthestudwallsandpre-compressingthewallpanelbeforeconnectingthetracktothestuds.Wallpanelizationandpre-compression,particularlyformulti-storycold-formedsteelconstruction,havebecomecommonpracticeinseveralregionsofNorthAmerica.Withpre-compression,itcanberelativelyensuredthatthestudwillbeseatedinthetrack,regardlessofthegapafterpre-compression.Atpresent,therearenospecificguidelinesfortheamountofpre-compressiveforcerequiredtoensureproperseating.Industrypracticehasbeentocompressthewallpaneluntilthestudsvisuallyseatinsidetheradiusofthetrackandbeforethestudsbegintobuckle.Jackingforcewillvarydependinguponthestudsizeandwallpanelheight,butistypicallyseveralhundredpoundsminimumperstud.Guidelinesforverificationofproperpre-compressionarenonexistent,buttypicallypre-compressionwillresultingapsof1/16in.(1.59mm)orlessforthemajorityofstud-to-trackconnections,withnogapexceeding1/8inch(3.18mm).Athirdmethodtohelpensureadequateendbearingistooversizethewebdepthofthetracktominimizeanygap.Trackoversized1/16to1/8in.(1.59mmto3.18mm)willusuallyhaveaflatwebbetweenthetrackradiithatisgreaterthanthedepthofthestud,enablingthestudtobeardirectlyonthewebinsteadofthetrackradii.Thismethodwilloftenbedesirablewhenbearingwallsarestick-framedinsteadofpanelizedandpre-compressed.Onedisadvantageisthattheoversizedtrackmaymakeaflatwallfinishmoredifficult.Forallthicknessofmaterials,testinghasshownthatthegapbetweenthesheathingandthefloorshouldbeequaltoorgreaterthanthegapbetweenthestudandthetrack.C2.5RoofsandCeilingsProperinstallationandalignmentofrooijoistsandceilingjo/sfsisnecessarytoensuretheproperloadtransferfromtherafterfceilingjoistconnectiontothewallframing.Toavoidprematurefailureatasupportandtoachievein-lineframing,fullbearingofthejoistonitssupportingwallframingmemberoraminimum1-1/2inch(38mm)endbearingisnecessary.

ScrewNominalSizeNominalScrewDiameter,d(inches)(mm)No.60.1383.51No.80.1644.17No.100.1904.83No.120.2165.491/4"0.2506.35oI10

AISIS200-12-C

D.CONNECTIONS

D1ScrewConnections

Dl.lSteel-to-SteelScrews

Screwsaretheprimaryfastenertypeusedincold-formedsteelframedconstruction,althoughthestandarddoesnotprecludetheuseofotherfastenertypes.In2001,ASTMC1513(ASTM,2010b)wasfirstpublished,coveringscrewsfortheconnectionofcold-formedsteelmembersmanufacturedinaccordancewithASTMSpecificationsC645andC955.Thisspecificationalsocoverstestmethodsfordeterminingperformancerequirementsandphysicalproperties.However,thetensileorshearstrengthmustbedeterminedbytestinaccordancewithAISIS904-08(AISI,2008).GeneralguidanceontheselectionofscrewsisgivenbytheCold-FormedSteelEngineersInstitutedocument"ScrewFastenerSelectionforCold-FormedSteelFrameConstruction"(CFSEI,2011).Properselectionandinstallationofscrewsarenecessarytoensurethedesignperformance.Screwsarespecifiedusinganominalsizedesignator,notbydiameter.TableDl-1definessuggestednominalscrewdiameters.TheinstallationrequirementsstatedinAISIS200arebasedonindustrypractice.Selectionofaminimumscrewsizeisbasedonthetotalsheetthicknessoftheconnection.Whererecommendationsarenotavailable.TableDl-2providessuggestedscrewsizeforsteel-to-steelconnectionsasafunctionofpointstyle,perASTMC1513,andtotalcombinedthicknessofallconnectedsteelmembers.

TableDl-1SuggestedScrewBodyDiameter

ScrewSizePointStyleTotalThicknessofSteel(inches)(mm)1/410.024-0.0950.61-2.41620.036-0.1000.91-2.54820.036-0.1000.91-2.541020.036-0.1100.91-2.791220.050-0.1401.27-3.561420.060-0.1201.52-3.051820.060-0.1201.52-3.05830.100-0.1402.54-3.561030.110-0.1752.79-4.451230.090-0.2102.29-5.331430.110-0.2502.79-6.351240.175-0.2504.45-6.351/440.175-0.2504.45-6.35124.50.145-0.3123.68-7.921250.250-0.5006.35-12.71/450.250-0.5006.35-12.7CommentaryontheNorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,2012Edition

HEXHEADLOWPROFILEHEAD

TYPICALLYSCREWFASTENEDTHRUTHINNERSTEELTOTHICKERSTEELASSHOWN.

THREADSSHALLPROTRUDETHROUGHSTEEL

FigureDl-1-ScrewGripRange

TableDl-2SuggestedScrewSizesForSteel-to-SteelConnections

1Combinedthicknessofallconnectedsteelmembers

11

12

AISIS200-12-C

D1.4StrippedScrewsItisunreasonabletoexpectthattherewillbenostrippedscrewsinaconnection.ResearchattheUniversityofMissouri-Rolla,(Sokoletal.,1999)hasshownthatthestructuralperformanceofasingle-shearscrewconnectionisnotcompromisedifscrewsintheconnectionhavebeeninadvertentlystrippedduringinstallation.Thisresearchservesasthebasisfortherequirementsofthestandard.D1.5SpacingandEdgeDistanceAISISlOO[CSAS136],(AISI,2012a;CSA,2012)stipulatesthatthecenter-to-centerspacingofscrewsbeatleastthree(3)timesthescrewdiameter.Duringinstallation,ifthisspacingisonlytwo(2)timesthediameter,researchattheUniversityofMissouri-Rolla(Sokoletal.,1999)hasshownthatthestructuralperformanceoftheconnectionisreduced.Guidelinesforcenter-to-centerspacingoflesstwo(2)timesthediameterarenotstipulatedbecausethescrewheaddiameterprecludesasmallerspacing.TheUniversityofMissouri-Rollaresearchservesasthebasisfortherequirementsinthestandard.D1.6GypsumBoardThestandardemploystheuseoftheapplicablebuildingcodeastheguideforprovisionsthatcovertheinstallationandattachmentofgypsumpanelstocold-formedsteelframing.ThemodelbuildingcodesintheUnitedStatesreferenceASTMC1007(ASTM,2011d)astheappropriatestandardforthegypsumboardattachmenttocold-formedsteelstructuralmembers.ThestandardrequiresthatscrewfastenersforgypsumboardtosteelconnectionsbeincompliancewithASTMC954(ASTM,2010a),ASTMC1002(ASTM,2007)orASTMC1513(ASTM,2010b),asapplicable,withabugleheadstyle.ASTMC954isforfasteningtosteelhavingathicknessfrom0.033inches(0.838mm)to0.112inches(2.84mm).ASTMC1002isforfasteningtosteelwithathicknesslessthan0.033inches(0.838mm).ASTMC1513isforfasteningtosteelwithathicknessnotgreaterthan0.118inches(2.997mm).D2WeldedConnections

Tomaintainacceptabledurabilityofaweldedconnection,theweldareamustbetreatedwithacorrosion-resistantcoating,suchasazinc-richpaint.Additionalguidanceonweldingofcold-formedsteelmembersisprovidedintheCold-FormedSteelEngineersInstitutedocument"WeldingCold-FormedSteel"(CFSEI,2010b).D3OtherConnections

Thestandardpermitstheuseofboltsandproprietaryfasteners,suchaspneumaticallydrivenpins,powder-actuatedfasteners,rivets,adhesives,andclinches.BoltscanbedesignedbyAISISlOO[CSAS136]equations.However,proprietaryfastenersmustbedesignedandinstalledinaccordancewiththemanufacturer'srequirements.ThesafetyfactortobeusedindesignistobedeterminedbyChapterFofAISISlOO[CSAS136].TheCold-FormedSteelEngineersInstitutepublishestechnicalnotespertainingtopowder-actuatedfastenersandpneumaticallydrivenpins(CFSEI,2012;CFSEI,2009).


13

E.MISCELLANEOUS

ElUtilities

El.lHoles

Thedesignshouldincludereferencestopre-punchholesizesorlimitationstoaccommodateelectrical,telecommunication,plumbingandmechanicalsystems.Field-cutholesaregenerallydiscouraged,butarenotuncommon.Field-cutholes,ifnecessary,arerequiredtocomplywithSectionB2.1ofthestandard.Thereareseveralmethodswherebyholescanbecutinthefield,suchasahole-punch,holesaws,andplasmacutters.Holesthatpenetrateanassemblycontainingsteelframingthathasafireresistanceratingwillneedtobedesignedwiththrough-penetrationfirestopsystems.Theacceptanceofthisfireresistancedesignisbasedontheapplicablebuildingcode.E1.2PlumbingDirectcontactwithcopperpipingshouldbeavoidedinordertopreventgalvanicactionfromoccurring.Methodsforpreventingthecontactfromoccurringmaybethroughtheuseofnon-conductivenon-corrosivegrommetsativebpenetrationsorthroughtheuseofnon-metallicbrackets(a.k.a.isolators)fastenedtoholdthedissimilarmetalbuildingproducts(e.g.piping)awayfromthesteelframing.Plasticpipedoesnotrequireprotectionifitisincontactwiththecold-formedsteelframingmember,butconsiderationshouldgiventotheinstallationofnon-metallicbracketstoholdthepipeawayfromtheholeinthesteelinordertopreventnoiseandpreventthesteelfromcuttingintothepipe.E1.3Electrical

Non-metallicsheathedwiringmustbeseparatedfromthecold-formedsteelframingmemberinordertocomplywiththeNationalElectricalCode(NFPA,2011).ContainedwithintheNationalElectricalCodeisaprovisionthatrequiresnon-metallicsheathedcableto"beprotectedbybushingsorgrommetssecurelyfastenedintheopeningpriortotheinstallationofthecable."Cablefollowingthelengthofaframingmemberwillneedtobesecured(e.g.supported)atsetlengths.Forthispurpose,smallholesinthewebmaybebeneficialfortheattachmentoftie-downs(e.g.nyloncableties,nylonzipperties,etc).Wheninstallingwiringorcableswithinaframingmember(e.g.throughorparalleltothemember),theintentoftheNationalElectricalCodefurtherrequiresthatthewiringorcablesbelocated1-1/4inches(32mm)fromtheedgeoftheframingmember.When2-1/2inch(64mm)-widewallstudsareused,therestrictionsconcerningedgeclearanceapply.E2Insulation

Thecavityinsulationmustbeinstalledsuchthatthewidthoftheinsulationextendsfromthefaceoftheivebofoneframingmembertothefaceoftheivebofthenextframingmember.Inthecaseofcold-formedsteelframing,designsshouldspecify"fullwidth"insulationinordertodifferentiatetheinsulationthatisnormallysupplied(e.g.nominalwidth).Toenhancethethermalperformanceofcold-formedsteelframedconstruction,boardinsulation(e.g.continuousinsulationorinsulatingsheathing)maybeusedinconjunctionwithcavityinsulation.Guidanceontheuseofboardandbattinsulationisgivenin"ThermalDesignandCodeComplianceforCold-FormedSteelWalls"(SFA,2008).Designsshouldalsotakeinto

14

AISIS200-12-C

considerationtheeffectsofmoisturewhenassessingtheapplicationofbothcavityandcontinuousinsulation,inthiscasedewpoint.TheASHRAEHandbookofFundamentalscontainsinformationusefulfordeterminingthevalueofdewpoint(ASHRAE,2009).


15

REFERENCES

(AGA,2006),HotDipGalvanizingForCorrosionProtection-ASpecifier'sGuide,AmericanGalvanizersAssociation,Aurora,CO,2006.(AISI,2012a),NorthAmericanSpecificationfortheDesignofCold-FormedSteelStructuralMembers,AISISlOO-12,AmericanIronandSteelInstitute,Washington,DC,2012.(AISI,2012b),NorthAmericanStandardforCold-FormedSteelFraming-GeneralProvisions,AISIS200-12,AmericanIronandSteelInstitute,Washington,DC,2012.(AISI,2012c),NorthAmericanStandardforCold-FormedSteelFraming-ProductData,AISIS201-12,AmericanIronandSteelInstitute,Washington,DC,2012.(AISI,2012d),NorthAmericanStandardforCold-FormedSteelFraming-TrussDesign,AISIS214-12,AmericanIronandSteelInstitute,Washington,DC,2012.(AISI,2011),NorthAmericanStandardforCold-FormedSteelFraming-NonstructuralMembers,AISIS220-11,AmericanIronandSteelInstitute,Washington,DC,2011.(AISI,2008),StandardTestMethodsforDeterminingtheTensileandShearStrengthofScrews,AISIS904-08,AmericanIronandSteelInstitute,Washington,DC,2008.(AISI,2007),DesignGuideforCold-FormedSteelFraming,DllO-07,AmericanIronandSteelInstitute,Washington,DC,2007.(ASHRAE,2009),ASHRAEHandbookFundamentals,AmericanSocietyofHeatingRefrigeratingandAir-conditioningEngineers,Atlanta,GA,2009.(ASTM,2011a),StandardSpecificationforSteelSheet,Carbon,Metallic-andNonmetallic-CoatedforCold-FormedFramingMembers,ASTMA1003/1003M-11,ASTMInternational,WestConshohocken,PA,2011.(ASTM,2011b),StandardSpecificationforNonstructuralSteelFramingMembers,ASTMC645-11,ASTMInternational,WestConshohocken,PA,2011.(ASTM,2011c),StandardSpecificationforLoad-Bearing(TransverseandAxial)SteelStuds,Runners(Tracks),andBracingorBridgingforScrewApplicationofGypsumBoardandMetalPlasterBases,ASTMC955-11,ASTMInternational,WestConshohocken,PA,2011.(ASTM,2011d),StandardSpecificationforInstallationofLoadBearing(TransverseandAxial)SteelStudsandRelatedAccessories,ASTMC1007-11,ASTMInternational,WestConshohocken,PA,2011.(ASTM,2010a),StandardSpecificationforSteelDrillScrewsfortheApplicationofGypsumPanelProductsorMetalPlasterBasestoSteelStudsFrom0.033in.(0.84mm)to0.112in.(2.84mm)inThickness,ASTMC954-10,ASTMInternational,WestConshohocken,PA,2010.(ASTM,2010b),StandardSpecificationforSteelTappingScrewsforCold-FormedSteelFramingConnections,ASTMC1513-10,ASTMInternational,WestConshohocken,PA,2010.(ASTM,2009),StandardPracticeforEstablishingConformancetotheMinimumExpectedCorrosionCharacteristicsofMetallic,Painted-Metallic,andNonmetallic-CoatedSteelSheetIntendedforUseasCold-FormedFramingMembers,ASTMA1004/A1004M-99(2009),ASTMInternational,WestConshohocken,PA,2009.(ASTM,2007),StandardSpecificationforSteelSelf-PiercingTappingScrewsfortheApplicationofGypsumPanelProductsorMetalPlasterBasestoWoodStudsorSteelStuds,ASTMC1002-07,ASTMInternational,WestConshohocken,PA,2007.(CFSEI,2012),PowderActuatedFastenersinCold-FormedSteelConstruction,TechNoteF301-12,Cold-FormedSteelEngineersInstitute,Washington,DC,2012.

16

AISIS200-12-C

(CFSEI,2011),ScrewFastenerSelectionforCold-FormedSteelFrameConstruction,TechNoteF102-11,Cold-FormedSteelEngineersInstitute,Washington,DC,2011.(CFSEI,2010a),TopTrackLoadDistributionMembers,TechNoteW104-10,Cold-FormedSteelEngineersInstitute,Washington,DC,2010.(CFSEI,2010b),WeldingCold-FormedSteel,TechNote560-bl,Cold-FormedSteelEngineersInstitute,Washington,DC,2010.(CFSEI,2009),PneumaticallyDrivenPinsForWoodBasedPanelAttachment,TechNoteF300-09,Cold-FormedSteelEngineersInstitute,Washington,DC,2009.(CFSEI,2007a),DurabilityofCold-FormedSteelFramingMembers,TechNoteDOOl-07,Cold-FormedSteelEngineersInstitute,Washington,DC,2007.(CFSEI,2007b),CorrosionProtectionforCold-FormedSteelFraminginCoastalAreas,TechNoteD200-07,Cold-FormedSteelEngineersInstitute,Washington,DC,2007.(CSA,2012),NorthAmericanSpecificationfortheDesignofCold-FormedSteelStructuralMembers,CAN/CSAS136-12,CanadianStandardsAssociation,Mississauga,Ontario,Canada,2012.(CSA,2009),ConnectorsforMasonry,CAN/CSA-A370-04(R2009),CanadianStandardsAssociation,Mississauga,Ontario,Canada,2009.Dawe,J.L.(2005),"ExperimentalEvaluationoftheStrengthandBehaviourof16-and18-gaugeColdFormedSteelTopTrackSystems-92mmand152mm,16"and24"Spans(W&W/O2X4and2X6WoodTopPlates,"UniversityofNewBrunswickStructuralEngineeringLaboratory,SaintJohn,NewBrunswick,Canada,2005.Findlay,P.F.(2005),"ServiceabilityIssuesPertainingtoLoadBearingandNon-LoadBearingSteelFramedWalls,"ThesispresentedtothefacultyoftheUniversityofMissouri-Rollainpartialfulfillmentofthedegree.MasterofScience,Rolla,MO,2005.Fox,S.R.(2003),"TheStrengthofStiffenedCFSFloorJoistAssembliesWithOffsetLoading,"AmericanIronandSteelInstitute,Washington,DC.(ICC,2012),InternationalBuildingCode,InternationalCodeCouncil,Washington,DC,2012.(NAHB-RC,2003),Cold-FormedSteelTopLoadBearingTracks,NAHBResearchCenter,UpperMarlboro,MD,2003.(NFPA,2011),NationalElectricalCode(NFPA70),NationalFireProtectionAssociation,Quincy,MA,2011.Sokol,M.A.,LaBoube,R.A.,andYu,W.W.(1999),"DeterminationoftheTensileandShearStrengthsofScrewsandtheEffectofScrewPatternsonCold-FormedSteelConnections,"CivilEngineeringStudy98-3,Cold-FormedSteelSeries,CenterforCold-FormedSteelStructures,UniversityofMissouri-Rolla,Rolla,MO,1999.(SFA,2008),ThermalDesignandCodeComplianceforCold-FormedSteelWalls,SteelFramingAlliance,Washington,DC,2008.Yu,W.W.andLaBoube,R.A.(2010),Cold-FormedSteelDesign,4*Edition,JohnWiley&Sons,NewYork,NY,2010.

American25MassachusettsAvenue,NWIronandSteelSuite800InstituteWashington,DC20001www.steel.org