Please&add&relevant&logo&here& Exposed(Wood(in(Fire(Resis/ve(Applica/ons( ( ( ( David&Barber,&Arup& & &&&& Disclaimer:+This+presenta1on+was+developed+by+a+third+party+and+is+not+funded+by+ WoodWorks+or+the+So=wood+Lumber+Board.&
The&Wood&Products&Council &is& a®istered&provider&with&the& American&InsAtute&of&Architects& ConAnuing&EducaAon&Systems& (AIA/CES),&Provider&#G516.& &! Credit(s)&earned&on&compleAon& of&this&course&will&be&reported&to& AIA&CES&for&AIA&members.& CerAficates&of&CompleAon&for& both&aia&members&and&nonpaia& members&are&available&upon& request.& & & This&course&is®istered&with&AIA& CES&for&conAnuing&professional& educaaon.&as&such,&it&does¬& include&content&that&may&be& deemed&or&construed&to&be&an& approval&or&endorsement&by&the& AIA&of&any&material&of& construcaon&or&any&method&or& manner&of&handling,&using,& distribuang,&or&dealing&in&any& material&or&product.& QuesAons&related&to&specific&materials,& methods,&and&services&will&be&addressed&at& the&conclusion&of&this&presentaaon.& & &
Course(Descrip/on( For&buildings,&the&fire&resistance&of&structural&elements&is&a&codePsApulated& requirement&oten&dictated&by&the&construcaon&type&chosen&rather&than&building& materials&used.&wood&structures&are&unique&in&that&they&can&be&unprotected&while& sall&providing&a&level&of&fire&resistance.&however,&both&designers&and&jurisdicaons& tend&to&be&unfamiliar&with&this&approach.&& This&presentaAon&will&cover&the&use&of&a&variety&of&exposed&structural&wood& products&(solid&sawn&lumber,&nail&laminated&amber,&glue&laminated&amber&and& cross&laminated&amber)&in&different&firepresistant&applicaaons&for&construcaon& Types&III,&IV&and&V.&Discussion&will&include&implementaAon&of&char&calculaAons,& consideraaons&for&connecaons,&and&informaaon&on&when&calculaaons&or&fire&tests& are&required&for&proving&fire&resistance&in&these&scenarios.&with&a&bezer& understanding&of&the&challenges&and&potenaal&soluaons,&azendees&will&be&able&to& confidently&pursue&exposed&wood&for&their&projects.&
Learning(Objec/ves( 1. & Review&provisions&of&the&InternaAonal&Building&Code&specific&to&the& use&of&unprotected&wood&products&in&firepresisave&members&and& assemblies.& & 2.&Discuss&calculaAon&of&fire&resistance&for&exposed&wood&members,& including&applicability&of&char&calculaaons.& & 3.&Highlight&opAons&and&configuraAons&for&connecAons&in&fire& resistanceprated&exposed&wood&systems.& & 4.&Explore&design&paths&for&proving&fire&resistance&acceptability&of& exposed&wood&systems,&including&the&use&of&alternaave&design& methods&and&materials.& &
Content! Why timber?! IBC Requirements! Fire fundamentals! Applications! Details! Summary
Why timber?! Sustainability! Aesthetics, Innovation! Changing technology
Current approach Efficient construction Prefabrication CLT Glulam NLT LVL
Current approach and the future Using combinations of materials Designing efficient and sustainable buildings 2000 2008 2012 2013 2017? Platform CLT Glulam/RC CLT CLT/Glulam Hybrid
Wood Construction and the IBC Combustible construction Type III, IV, V Non-combustible construction Type I, II Wood is combustible construction Issues to address for exposed wood: Interior finishes Fire resistance ratings (FRR)
Wood Construction and the IBC Type III: Up to 6 stories (B), 5 stories (R) 1 hr FRR load bearing structure, 2hr FRR load bearing external walls Type IV: As for Type III, but using heavy timber Type V: Low rise, few restrictions
What Does a Type III Building Look Like? The Wood floors and framing (interior) Up to 6 floors, with sprinklers Podium construction with concrete to lower floors Exterior walls are non-combustible, or wood covering (to 40ft) or FRT wood (to 60ft) 11 Duratherm Presentation
What Does a Type IV Building Look Like? Up to 6 floors, with sprinklers Wood beams, columns, floors, roof permitted Exterior walls are noncombustible, or FRT wood 12 Duratherm Presentation
A Modern Type IV Building Up to 6 floors, with sprinklers Exposing the wood Use of steel or concrete, where appropriate (hybrid construction) Glulam beams, columns; CLT floors and walls 13
Wood Construction and the IBC Types V, IV and III wood can be exposed
Wood Construction and the IBC Types V, IV and III wood can be exposed
Wood Construction Trending Methods Light frame vs mass wood Type IIIA, Type IV and Type VA classifications Seeing more 5 on 1 for R-2, 6 on 1 for B Differences in interpretation regarding Type IIIA and Type IV More wood as an interior finish From decoi Architects
Exposed Wood and Fire What s to know?
All materials have problems with fire Steel Loses strength and stiffness. Requires additional protection Concrete Unpredictably spalls. Use additional cover Wood Burns & forms a predictable self-insulating char
Fire fundamentals Mass wood structure encapsulated in gypsum compliance? Exposed wood being demanded by architects and developers What is the fire response of engineered wood products CLT, NLT, LVL, glulam
Exposed Wood Tested assemblies? Where is the UL listing Reliance on tested assemblies Exposed wood is not UL listed AHJ acceptance?
Exposed Wood Real engineering What does the code allow? What can be engineered? Understanding wood performance in fire Using existing research and test data Engineered calculations From decoi Architects
What is a Fire Resistance Rating? Structural resistance Integrity Insulation (from CLT Handbook, US Edition )
What is Interior Finish Flammability? Resistance to flame spread and a measure of smoke development - classes A, B and C ASTM E84 Standard Test Method for Surface Burning Characteristics of Building Materials ( Steiner tunnel ) From Nordic
What is Interior Finish Flammability? Type IV - exempt Wood = Class C Some wood products will achieve B AWC Design for Code Acceptance 1 Flame spread performance of wood products used for interior finish
Wood - Fire fundamentals! Charring! Well understood and researched
Wood - Fire fundamentals Wood performance in fire is predictable Load carrying under fire is reliable Design for fire resistance, through increasing wood cover Wood has inherent passive fire protection
Wood - Fire fundamentals FRR of wood NDS Chapter 16 Method explained in detail in TR-10 Part 3 provides all required design information TR-10 is a compliant methodology for providing exposed wood FRR
Wood - Fire fundamentals Determination of charring rate? History of fire tests:! Standard furnace tests! Tests in real fires! Carried out internationally! Correlations based on density, moisture, grain direction, sawn or engineered wood Figure 2-2 from TR-10
Wood - Fire fundamentals 90 minute FRR fire test on 270mm x 415mm glulam beam (from APA)
Wood - Fire fundamentals Long term (nominal) char rate = 1.5 in/hr Design char rate increased by 20%: Corner rounding Fissures Zero strength layer behind the char For 1hr exposure = 1.8in/hr For 2hrs = 1.58in/hr From APA
Wood - Fire fundamentals Calculating an FRR What is the area (b x d) needed? What additional wood cover is required, for an FRR (B x D) The difference (B b) is the sacrificial char layer TR-10 Fig 1-2
Fire protection fundamentals! Steel! Concrete! Wood
Wood - Fire fundamentals! Glulam, LVL, sawn lumber! NLT! CLT
Wood - Fire fundamentals! Glulam, LVL, sawn lumber Follow TR-10! NLT Follow TR-10! CLT Follow TR-10! IBC NDS TR-10 Section 722.1 Chapter 16 Part 3
CLT A panelized system for walls and floors Similar to concrete flat slab construction - no concealed spaces Highly accurate construction All pre-cut and delivered to site Screw-fixed into place Very strong and very durable
CLT - Fire fundamentals Does it char like normal wood? What is delamination? Is all CLT constructed the same?
CLT - Fire fundamentals
CLT - Fire fundamentals
CLT - Fire fundamentals
Connections Can be expressed where no fire rating is required Where exposed and need an FRR:! Bearing connections! Shear connections - concealed steel plates
FRR Connections Design to conceal the whole connection Issues:! Char rate at the connection! How much is concealed! Strength and stiffness of wood, that is decreasing in volume From Simpson Strongtie May need detailed analysis
CLT Connections Proven through fire testing Concrete topping? Lap splice Spline splice From KLH
Exposed Wood! Not all authorities are supportive of exposed wood! Sometimes an alternative materials submission is required to support use! Significant variance in interpretation of the IBC, with regard to exposed wood! The impact of exposed wood can be analysed and accounted for
Exposed Wood and Fire - Questions?
Ques/ons?( This&concludes&The&American& InsAtute&of&Architects&ConAnuing& EducaAon&Systems&Course& David(Barber( Arup& david.barber@arup.com&