Fire Safety of Timber Buildings

Fire%Safety%of%Timber%Buildings:%A%Research%Review%

David&Barber&Arup,&Washington&DC&[email protected]&24=26&September&2014&

Course%Descrip@on%

Recent&architectural&trends&in&sustainable&urban&densificaEon&have&spurred&a&movement&toward&increasingly&larger&buildings&made&from&Ember&products&or&a&combinaEon&of&wood&and&other&materials.&Many&Ember&building&concepts&are&moEvated&by&their&suggested&advantages&in&sustainability&resulEng&from&the&use&of&wood&as&a&renewable&and&low=carbon&construcEon&material.&In&furthering&wood's&evoluEon&as&a&structural&material&in&urban&seLngs,&designers&are&interested&to&beMer&understand&the&implicaEons&of&Ember&use&with&regard&to&fire&and&life&safety.&&Ensuring&&occupant&safety&and&the&protecEon&of&property&requires&assessing&the&fire&performance&of&structural&systems&and&design&applicaEons.&This&presentaEon&will&include&the&findings&of&a&study&performed&in&coordinaEon&with&the&Fire&ProtecEon&Research&FoundaEon.&&&

Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.

Learning%Objec@ves%

1.&Explain&the&current&state&of&fire&and&life&safety&codes&and&standards&as&they&relate&to&allowing&Ember&as&a&structural&material.&

2.&Describe&the&current&understanding&of&fire&performance&of&tall&Ember&buildings,&including&results&of&fire&tesEng&and&examples&of&high=rise&Ember&buildings.&

3.&IdenEfy&areas&for&future&tesEng&and&research&needed&to&demonstrate&safety&in&tall&Ember&buildings.&

4.&Understand&the&importance&of&effecEve&risk&communicaEon&with&Ember&building&stakeholders.&

&

“The&Wood&Products&Council”&is&a&Registered&Provider&with&The&American&InsEtute&of&Architects&ConEnuing&EducaEon&Systems&(AIA/CES),&Provider&#G516.&&!Credit(s)&earned&on&compleEon&of&this&course&will&be&reported&to&AIA&CES&for&AIA&members.&CerEficates&of&CompleEon&for&both&AIA&members&and&non=AIA&members&are&available&upon&request.&&&

This&course&is&registered&with&AIA&CES&for&conEnuing&professional&educaEon.&As&such,&it&does&not&include&content&that&may&be&deemed&or&construed&to&be&an&approval&or&endorsement&by&the&AIA&of&any&material&of&construcEon&or&any&method&or&manner&of&handling,&using,&distribuEng,&or&dealing&in&any&material&or&product.&___________________________________________

QuesEons&related&to&specific&materials,&methods,&and&services&will&be&addressed&at&the&conclusion&of&this&presentaEon.&&

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6

Introduction •  Buildings have to be safe during building use •  Fire safety includes:

-  Safety from fire -  Occupant evacuation -  Emergency operations

-  Safety from structural failure -  Structural stability

7

Introduction •  Everyone is aware that wood burns

8

Timber Fire Performance •  Fire performance -  Light timber vs. heavy timber

9

Timber Fire Performance •  Light timber framing -  2x studs and joists -  I-joists, trusses

•  Stick frame construction

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Timber Fire Performance •  Fire protection -  Light timber

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Timber Fire Performance •  Heavy timber frame products meeting prescriptive min. sizes -  Solid sawn -  Engineered wood products

Glue laminated wood (Glulam) Laminated Veneer Lumber (LVL)

12

Timber Fire Performance •  Heavy timber frame products -  Engineered wood products

Cross Laminated Timber (CLT)

13

Timber Fire Performance •  Fire protection -  Heavy timber

Sacrificial char layer Solid “cold” timber

14

Timber Fire Performance •  Fire performance -  Light timber vs. heavy timber

15

Timber Fire Performance •  Charring -  Well-understood -  Predictable -  ~0.025 in/min [0.7mm/min]

16

Timber Fire Performance •  Timber Frame 2000 -  Cardington, UK -  Fire resistance of a mid-rise timber building

17

Timber Fire Performance •  Natural fire testing: -  Light timber framing -  Combustible lining vs. gypsum lining -  Sprinklered vs. non-sprinklered

Sprinkler protection Combustible lining Gypsum board lining

18

Timber Fire Performance •  CLT assemblies -  Charring rate consistent with wood (~0.025 in/min [0.7mm/

min]) -  Predictable behavior -  Improved performance with gypsum board protection

19

Timber Fire Performance •  Fire protection for connections

20

Timber Fire Performance •  Timber composite assemblies -  CLT box beams -  Fire performance based on testing -  Over 2-hour ratings for assemblies

21

Timber Fire Performance •  Fire performance -  Composite members -  Timber concrete floors

22

Further Research •  Penetrations -  Fire-stopping

23

Further Research •  Contribution of timber to room

fires -  Delamination -  Self-extinguishment

24

Further Research •  Perception of risk -  Improved understanding of fire

performance of timber needed across the industry

25

Building Regulations in Timber •  International regulations

26

Building Regulations in Timber •  International regulations

Country Applicable Building Code Maximum # of Stories Sprinklered Unsprinklered

Australia 2013 Building Code of Australia (BCA) 3 3

Austria Austrian Building Codes 8 (*72 feet) 3

Canada 2010 National Building Code of Canada (NBCC)

4 3

Germany 2012 Federal Building Code 8 (*59 feet) 3

Sweden 2013 Planning and Building Act 8 2

United Kingdom

2010 Building Regulations 5** 4**

United States 2012 International Building Code (IBC) 5 4

* Indicates a height limit in addition to a maximum story limit

27

Building Regulations in Timber •  Prescriptive Design -  Code changes

•  Performance based design -  Alternative solution to prescriptive codes

28

Gaining Approval •  Option 1 – Prescriptive route -  TF 2000, UK -  FPInnovations, North America

•  Long term solution -  Requires significant justification -  Testing, understanding, discussion, agreement

-  Takes a significant amount of time -  3-year code cycles (USA)

Fire Safety

29

Gaining Approval •  Option 2 – Performance route -  All tall timber structures to date -  UK, Australia, Europe, Canada

-  Up to the discretion of the approval authority -  Technical justification for safety -  No different to any other innovative building solution

Fire Safety

30

Gaining Approval •  Fire protection strategies -  Passive -  Encapsulation -  Compartmentation -  Egress

-  Active -  Sprinklers -  Detection and alarm

31

Gaining Approval •  Improved understanding of fire risks -  Penetrations -  Connections -  Contribution exposed timber to room fires -  Potential for self-extinguishment

Fire Safety

32

Gaining Approval •  Address Perception of risk -  Improved understanding -  Technical justification -  Risk communication

33

Risk Communication

•  We cling to the myth that timber construction presents risks, while concrete and steel do not. Nonsense. Every material presents risks, but we manage them in different ways…

-  Russell Fortmeyer, Arup

34

Timber Buildings •  Heavy timber frame construction -  Post and beam construction

35

Timber Buildings •  Heavy timber frame construction -  CLT Panelized construction

36

Timber Buildings •  Heavy timber frame products -  Composite wood products

Post-tensioned timber

37

Timber Buildings •  Heavy timber frame products -  Composite wood products

Timber-concrete composite floors

38

Contemporary Examples •  Panelized construction -  Stadhaus, London, UK, 2009

39

Contemporary Examples •  Panelized construction -  Stadhaus, London, UK, 2009

40

Contemporary Examples •  Panelized construction -  Forte Building, Melbourne, Australia, 2013

41

Contemporary Examples •  Panelized construction -  Forte Building, Melbourne, Australia, 2013

42

Contemporary Examples •  Post and beam construction -  Life Cycle Tower One, Austria, 2012

43

Contemporary Examples •  Post and beam construction -  Wood Innovation Design Centre, Prince George, Canada, 2014

44

Timber Buildings •  Global precedent

45

Future Timber Buildings •  Feasibility studies

“Office Building of the Future”, CEI Architecture, 2013 Timber Tower, SOM, 2013

46

Future Timber Buildings •  Feasibility examples -  Case for Tall Wood

30-story high-rise, Michael Green Architecture, 2012

47

Next Steps •  USDA Grant -  10+ story timber building -  $2mil for design development -  Full design team

•  Holistic Timber Design -  Acoustics -  Facades -  Structural -  Seismic, vibrations, stability

-  Sustainability -  Fire / Life Safety

48

Acknowledgements •  Fire Protection Research Association •  National Fire Protection Association •  WoodWorks •  American Wood Council

Ques@ons?%

This&concludes&The&American&InsEtute&of&Architects&ConEnuing&EducaEon&Systems&Course&

David%Barber%

Arup,%Washington%DC%

[email protected]%