1. business and industrial
2. construction

6
Step 6 – Further Design Assistance
(Appendices)
ThepreviousStepsintheGuiderequireconsiderationofadditionalinformationontopics
closelylinkedtothedesignoffireandsoundconstruction.Thefollowingappendicescover
structuraldesignconsiderations,DeemedtoSatisfyfirerequirementsnotcoveredbythis
Guide,otherdesignreferencesandaGlossary.
Appendix A – Resolving Structural
Design Considerations
ThefollowingissuesshouldbetakenintoaccountinthestructuraldesignofClass2,3and9c
buildings:
Taller buildings
mean more wind
and greater loads.
• Lightermassthanmasonryconstruction–greaterattentionneedstobegiventoresistanceagainst
overturning.
• Greatereffectfromwindloadsthanexpectedfromtimber-frameddetachedhouses.Thisisduetoa
greaterheight-to-widthratio,resultinginaneedforattentiontoresistancetooverturning.
• Greaterimposedloadsthantimber-frameddetachedhousesbecauseoftheextraloadsassociated
withthefire-ratedwallandfloorelements.
• Needtoaccommodatelargernumberofpeoplethandetachedhousing,resultinginlargerapplied
loads.
• Mustbeconstructedusingspecificmethodsforattachmentofliningstoachievefireratings.
Seasoned or
engineered timber
can minimise
shrinkage in
higher structures.
• Greaterpotentialforshrinkageintallertimberbuildings.Shrinkagecanbeminimisedby:
–usingseasonedtimberorengineeredtimber;
–constructingbearersandjoistsinthesameplane;
–detailingtoavoiddifferentialshrinkagebetweendissimilarmaterials,e.g.steeltotimber;timber
tomasonry;and
–allowingforshrinkagewithrespecttoplumbing.
Itisrecommendedthataprofessionalstructuralengineerbeemployedtoaddresstheaboveissues
andstructuralperformanceingeneral.ThefollowingstandardsandGuidelinesshouldbecalledupon
toassist:
• AS1170.0–Structuraldesignactions–GeneralPrinciples.
• AS1170.1–Structuraldesignactions–permanent,imposedandotheractions(2002)providesthe
basisfordeterminationofappropriatedead,livedesignloadsandloadscombinations
• AS1170.2–Structuraldesignactions–windactions–whichprovidesthebasisforwindloads.
• AS1170.4–Structuraldesignactions–EarthquakeactionsinAustralia–whichprovidesguidance
anddesignproceduresforearthquakeforces.
• AS1720.1–Timberstructures–designmethods.
• ThoughwrittenforClass1buildings,AS1684–Residentialtimber-framedconstruction–canbe
usedasageneralguideforconstructionpracticesandsomedesignofmembersinbuildingsup
totwostoreys,providedtheappropriateadjustmentsaremadetotherelevantcriteriaincluding:
permanent,imposedandwindloads.Thisincludesallowablenotchingintoframingmembers.More
specificengineeringdesignofmembersisrequiredforthreeandfourstoreybuildings.
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
Page 62
Inadditiontotheabove:
• Selectdetailsthatminimisetheeffectsofshrinkage(especiallysincedifferentialshrinkagemayhave
anadverseimpactonthefunctionoffire-ratedwallandfloorelements).
• CheckthatdoublestudwallsboundingSoleOccupancyUnitsarecapableofsupportingmultistoreyloadpathsfromabove.Enlistinternalwallsifrequired.
• Checkthatanyelementssupportingloads(includingbracingelements)aretreatedasfire-resistant
constructionanddesignedaccordingly.Thisusuallyincludesallexternalwallsofthebuilding.
• Whererequired,solidtimberwithoutprotectivefire-gradeliningscanbedesignedtoperformasafireresistantelementbyallowingforanextracharringlayer.Aformulaisrequiredtoassistindetermining
thecorrectsizeandhelpisprovidedbyaseparatetimberindustrydocument(referreferencelist).
•
Appendix B – Deemed to Satisfy
Fire Requirements Not Covered
by this Guide
Thispublicationtriestoassistuserswantingtousetimber-framedconstructionunderoftheBCA’s
DeemedtoSatisfyfire-resistanceprovisions.Evenso,manyoftheseprovisionsextendbeyond
thescopeofthispublication.InordertohelpusersobtainamoreholisticunderstandingofBCA
requirements,checklistsareprovidedinTablesB1,B2andB3.
TheselistscoverthemainissuesraisedinPartsC1,C2andC3oftheBCA(beingthethreekeyparts
contributingtotheDeemedtoSatisfyProvisions).Thechecklistsaimtoinformreadersofwhatisand
isnotcoveredinthisGuide.Byknowingthis,userscanconfidentlyspeakwithconstructioncertifiers,
regulatorybodies,designers,headcontractorsandsubcontractorsabouttheroleoftimber-framed
constructionincomplyingwiththeBCA’sDeemedtoSatisfyProvisions.
Table B1: Checklist for BCA Part C1: Fire-Resistance and Stability.
BCA
Clause
Issue
Isassistanceonthisissueprovidedinthis
publication
C1.0
DeemedtoSatisfyProvisions
Yes
C1.1
TypeofConstruction
Yes–referSection4.2
C1.2
Calculatingthe'riseinstoreys'
No
C1.3
Buildingsofmultipleclassification
No
C1.4
Mixedtypesofconstruction
No
C1.5
TwostoreyClass2,3or9cbuildings Yes–referSection4.2
C1.6
Class4partsofbuildings
No
C1.7
Openspectatorstandsandindoor
sportsstadiums
No
C1.8
Lightweightconstruction
Yes–butonlyforthetimberpartsoflightweight
construction.Requirementsforfire-gradelinings
andothercomponentsaretheresponsibilityof
others,refertoSection4.4.7
C1.09
NorequirementsintheBCA
NA
C1.10
Firehazardproperties
No–adviceonsuitablespeciesandapplication
canbefoundonwww.timber.net.au
C1.11
Performanceofexternalwallsinthe
fire
No–Thisitemonlyappliestoconcreteexternal
walls
C1.12
Non-combustiblematerials
No–Notnecessarybutnotethatplasterboardand
fibre-cementsheetsaredeemednon-combustible
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
Page 63
Table B2: Checklist for BCA Part C2: Compartmentalisation and Separation.
BCA
Clause
Issue
Isassistanceonthisissueprovidedinthis
publication
C2.0
DeemedtoSatisfyProvisions
Yes
C2.1
ApplicationofPart
Yes–generalinformationonrelevantclauses
requiredtobeconsideredforadesign
C2.2
Generalfloorareaandvolume
limitations
No–butmayberelevanttoClass9cbuildings
C2.3
Largeisolatedbuildings
No–butmayberelevanttoClass9cbuildings
C2.4
Requirementsforopenspacesand
vehicularaccess
No–butmayberelevanttoClass9cbuildings
C2.5
Class9aand9cbuildings
Yes–Class9cbuildings
C2.6
Verticalseparationofopeningsin
externalwalls
Yes–designertointerpretrelevancethenif
required,selectanappropriatelyratedtimberdetail
C2.7
Separationbyfirewalls
No–designertointerpretrelevancethenif
required,selectanappropriatelyratedtimberdetail
C2.8
Separationofclassificationsinthe
samestorey
No–butreferpublicationBCACompliantSound-
andfire-ratedTimber-FramedConstruction–
DesignandConstructionGuideforClass5,6,
9aand9bBuildings–office,shopsandpublic
buildings
C2.9
Separationofclassificationsin
differentstories
No–butreferpublicationBCACompliantSound-
andfire-ratedTimber-FramedConstruction–
DesignandConstructionGuideforClass5,6,
9aand9bBuildings–office,shopsandpublic
buildings
C2.10
Separationofliftshafts
No–designertointerpretrelevancethenif
required,selectanappropriatelyratedtimberdetail
C2.11
Stairwaysandliftsinoneshaft
No
C2.12
Separationofequipment
No–designertointerpretrelevance,thenif
required,selectanappropriatelyratedtimberdetail
C2.13
Electricitysupplysystem
No–designertointerpretrelevance,thenif
required,selectanappropriatelyratedtimberdetail
C2.14
PubliccorridorsinClass2and3of
buildings
Yes–gotoSection5.10.1
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
Page 64
Table B3: Checklist for BCA Part C3: Protection of Openings.
BCA
Clause
Issue
Isassistanceonthisissueprovidedinthis
publication
C3.0
DeemedtoSatisfyProvisions
Yes
C3.1
ApplicationofPart
No–generalinformationonrelevantclauses
requiredtobeconsideredforadesign
C3.2
Protectionofopeningsinexternal
wall
No–butrelevanttoabuildingdesign
C3.3
Separationofexternalwallsand
associatedopeningsindifferentfire
compartments
No–butmayberelevanttoabuildingdesign
C3.4
Acceptablemethodsofprotection
No–butrelevanttoabuildingdesign
C3.5
Doorwaysinfirewalls
No–butmayberelevanttoabuildingdesign
C3.6
Slidingfiredoor
No–butmayberelevanttoabuildingdesign
C3.7
Protectionofdoorwaysinhorizontal
exits
No–butmayberelevanttoabuildingdesign
C3.8
Openingsinfire–isolatedexits
No–butmayberelevanttoabuildingdesign
C3.9
Servicepenetrationsinfire-isolated
exits
No
C3.10
Openingsinfire-isolatedliftshafts
No
C3.11
Boundingconstruction:Class2,3
and4buildings
Yes
C3.12
Openingsinfloorsandceilingsfor
services
Yes–refertoSections4.4.6and5.6
C3.13
Openinginshafts
Yes–refertoSection5.6
C3.14
Norequirements
No
C3.15
Openingsforservicesinstallation
No–butrelevanttoabuildingdesign
C3.16
Constructionjoints
Yes–refertoSections5.4
C3.17
Columnsprotectedwithlightweight
constructiontoachieveanFRL
No–butmayberelevanttoabuildingdesign
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
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Appendix C – Design References
Design References
Australian Building Codes Board
• BuildingCodeofAustralia(BCA)2009–Volume1&2
Australian Standards
• AS1530.4–Methodsforfiretestsonbuildingmaterials,componentsandstructures–
Fire-resistancetestsonelementsofconstruction.
• AS1684–ResidentialTimberFramedConstructionStandard.
• AS/NZS1267.1Acoustics–Ratingofsoundinsulationinbuildingsandbuildingelements.
• AS/NZS2908.2–Cellulosecementproducts–Flatsheets.
• AS4072.1–Componentsfortheprotectionofopeningsinfire-resistantseparatingelements–
Servicepenetrationandcontroljoints.
WoodSolutions.
Free resources
are available at
woodsolutions.com.au
Thefollowingpublicationsareavailableasfreedownloadsatwoodsolutions.com.au:
• #01Timber-FramedConstructionforTownhouseBuildingsClass1–
DesignandconstructionguideforBCAcompliantsound–andfire-ratedconstruction.
• #03Timber-FramedConstructionforCommmercialBuildingsClass5,6,9aand9b–
DesignandconstructionguideforBCAcompliantfire-ratedconstruction.
Test and Assessment Reports
BodycoteWarringtonfire(Aus)
• 22567AAssessmentReport:Thelikelyfireresistanceperformanceoftimber-framedwallslined
withplasterboardiftestedinaccordancewithAS1530.42005,September2008.
• 22567BAssessmentReport:ThelikelyfireresistanceperformanceofMRTFCwallfloorjunctions
iftestedinaccordancewithAS1530.42005,September2008.
• RIR22567BRegulatoryInformationReport:ThelikelyfireresistanceperformanceofMRTFC
wallfloorjunctionsiftestedinaccordancewithAS1530.42005,September2008.
• 2256701TestReport:Fireresistancetestofatimberwallfloorjunctioningeneralaccordance
withAS1530.42005,September2008.
• 2256702TestReport:Fireresistancetestofawallbeamjunctionwhentestedingeneral
accordancewithAS1530.42005,September2008.
ExovaWarringtonfireAustralia
• 2365300TestReport:Fireresistancetestoffloorjunctionsincorporatingtimber
andplasterboardingeneralaccordancewithAS1530.42005,November2009.
• 2365400TestReport:Fireresistancetestoffloorjunctionsincorporatingtimber
andplasterboardingeneralaccordancewithAS1530.42005,November2009.
• 2365500TestReport:Fireresistancetestoffloorjunctionsincorporatingtimber
andplasterboardingeneralaccordancewithAS1530.42005,November2009.
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
Page 66
Appendix D – Glossary
BCA
BuildingCodeofAustralia–Volume1–Class2to9Buildings.
Cavitybarrier
Anon-mandatoryobstructioninstalledinconcealedcavitieswithinfire-ratedwallorfloor/ceiling
systems.
Discontinuousconstruction
Awallsystemhavingaminimumof20mmcavitybetweentwoseparatewallframes(leaves)withno
mechanicallinkagebetweentheframesexceptattheperipheryi.e.topandbottomplates.
Constructionjoint
Discontinuitiesofbuildingelementsandgapsinfire-ratedconstructionrequiredbytheBCAto
maintainfireresistance.RefertoDeemed-to-SatisfyProvisionC3.16,Volume1,BCA.
Exit
Includesanyofthefollowingiftheyprovideegresstoaroadoropenspace:
• aninternalorexternalstairway
• arampcomplyingwithSectionDoftheBCA
• adoorwayopeningtoaroadoropenspace.
Fire-gradelining
Eitherfire-gradeplasterboard,fibre-cementoracombinationofboth,usedtoprovidetherequiredFire
ResistanceLevel(FRL)forwallsorfloor/ceilingsystems.Individualliningsmanufacturersshouldbe
contactedtodeterminetheextenttowhichagivenliningmaterialprovidesfire-resistingproperties.
Fire-isolatedstairorramp
AStairorrampconstructionofnon-combustiblematerialsandwithinafire-resistingshaftorenclosure.
Fire-isolatedpassageway
Acorridororhallwayoffire-resistingconstructionwhichprovidesegresstoafire-isolatedstairwayor
ramp.
Fire-protectivecovering
• 3mmfire-gradeplasterboard;or
• 2mmcellulosefibre-reinforcedcementsheetingcomplyingwithAS2908.2;or
• 2mmfibrousplasterreinforcedwith13mmx13mmx0.7mmgalvanizedsteelwiremeshlocated
notmorethan6mmfromtheexposedface;or
• Othermaterialnotlessfire-protectivethan13mmfire-gradeplasterboard.
Note:Fire-protectivecoveringmustbefixedinaccordancewithnormaltradepractice(e.g.joints
sealed).
FireResistanceLevel(FRL)
Theperiodoftimeinminutes,determineinaccordancewithSpecificationA2.3(oftheBCA)forthe
following:
• Structuraladequacy
• Integrity
• Insulation.
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
Page 67
Fire-resistingmineralwool
Compressible,non-combustible,fire-resistingmaterialusedtofillcavitiesandmaintainfireresistance
orrestrictthepassageofsmokeandgasesatgapsbetweenotherfire-resistingmaterials.
NOTE:Themineralwooltobeusedinallapplicationsinthismanual,mustbefire-resistingand
thereforemusthaveafusiontemperatureinexcessof1160ºC.‘Rockwool’typeproductsgenerally
meettheserequirements,while‘glasswool’productsdonot.
Fire-resisting(Fire-rated)
Asappliedtoabuildingelementmeans,havingtheFRLrequiredbytheBCAforthatelement.
Fire-resistingconstruction
ConstructionwhichsatisfiesVolume2oftheBCA.
Fire-resistingjunction
Theintersectionbetweenafire-ratedwallorfloor/ceilingsystemandoranotherratedornon-rated
system,whichmaintainthefireresistanceattheintersection.
Ensure your sealants
have the same
fire rating as the
materials they seal.
Fire-resistingsealant
Fire-gradematerialusedtofillgapsatjointsandintersectionsinfire-gradeliningstomaintainFire
ResistanceLevels.
Note:Thematerialshouldalsobeflexibletoallowformovementandwhererequiredwaterproofas
well.
Fire-sourcefeature
Either:
• thefarboundaryofaroadadjoiningtheallotment;or
• asideorrearboundaryoftheallotment;or
• anexternalwalloranotherbuildingontheallotmentwhichisnotofClass10.
Habitableroom
Aroomfornormaldomesticactivitiesandincludesabedroom,livingroom,loungeroom,musicroom,
televisionroom,kitchen,diningroom,sewingroom,study,playroom,familyroomandsunroom,but
excludesabathroom,laundry,watercloset,pantry,walk-inwardrobe,corridor,hallway,lobby,clothesdryingroom,andotherspacesofaspecialisednatureoccupiedneitherfrequentlynorforextended
periods.
Internalwalls
Wallswithin,betweenorboundingseparatingwallsbutexcludingwallsthatmakeuptheexteriorfabric
ofthebuilding.
Note:FirewallsorcommonwallsbetweenseparatebuildingsorclassificationsareNOTinternalwalls.
Lightweightconstruction
Constructionwhichincorporatesorcomprisessheetorboardmaterial,plaster,render,sprayed
application,orothermaterialsimilarlysusceptibletodamagebyimpact,pressureorabrasion.
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
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Non-combustible
AppliedtoamaterialnotdeemedcombustibleunderAS1530.1–CombustibilityTestsforMaterials;
andappliedtoconstructionorpartofabuilding–constructedwhollyofmaterialsthatarenotdeemed
combustible.
PerformanceRequirements
Theobjectives,functionalstatementsandrequirementsintheBuildingCodeofAustraliathatdescribe
thelevelofperformanceexpectedfromthebuilding,buildingelementormaterial.
Rw
RefertoWeightedsoundreductionindex.
Unit
Sole-Occupancyunit.
Weightedsoundreductionindex(Rw)
TheratingofsoundinsulationinabuildingorbuildingelementasdescribedinAS/NZS1267.11999.
#02 • Timber-framed Construction for Multi-residential Buildings Class 2, 3 & 9c
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