FIRE SPRINKLER INTERNATIONAL 2014
21 MAY 2014
LONDON, ENGLAND
FIRE HAZARDS IN TIMBER BUILDINGS
AND THEIR NEED FOR SPRINKLERS
Casey C. Grant, Research Director
Fire Protection Research Foundation
Quincy, Massachusetts USA
Fire Hazards in Timber Buildings
and their Need for Sprinklers
AGENDA
1) Overview and Background
2) Timber Building Construction
3) Building Regulations for Timber
4) Timber Fire Performance
5) Knowledge Gaps & Future Direction
1) Overview and Background
“FIRE HAZARDS IN TIMBER BUILDINGS AND THEIR
NEED FOR SPRINKLERS”
• Focus of this presentation:
o Fire hazards…
o Timber buildings…
o Tall wood buildings…
• Key focus: “Fire Safety Challenges
of Tall Wood Buildings”
• FPRF Report, Dec 2013
• Report Author: Arup
• Phase 1 Study
• Available on FPRF Website
www.nfpa.org/foundation
1) Overview and Background
FPRF PROJECT BACKGROUND
• Recent architectural trends include design
and construction of increasingly tall buildings
with structural components
• Using components of laminated wood
referred to by names such as:
•
•
•
cross laminated timber (CLT),
laminated strand lumber (LSL)
glued laminated timber (Glulam)
• Construction currently underway on buildings
up to 10 stories in Australia, Austria, Canada and Norway
• Motivation includes sustainability and green approach
(use of renewable construction materials)
• Questions on claims of safety exceeding other construction
1) Overview and Background
FPRF PROJECT ORIGIN AND DEVELOPMENT
• Need exists to clarify building performance under
credible fire scenarios.
• Questions on characteristics (e.g., fire service
operations, interior/exterior flame spread, structural
stability, fire exposure hazard, etc)
• Project funded by PIRG – Property
Insurance Research Group
• Project contractor was Arup
• Project started earlier in 2013
• Phase 1 completed December
2013
1) Overview and Background
FPRF PROJECT SCOPE AND TASKS
• Focus on buildings 6 stories and greater
• Intent is to consider fire protection features that are
functioning, or are partially or fully impaired
• Objectives (overall):
• Characterize the fire performance of tall wooden structures.
• Define the necessary design and material requirements
to achieve a level of safety and property
protection equal to or above steel structures.
• Communicate the results to serve as a guide
for architects, engineers, and code officials.
• Phase 1 Task 1: Literature Review
• Phase 1 Task 2: Gap Analysis
1) Overview and Background
REPORT: INTRODUCTION
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•
•
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1.1) Phase 1 of the Fire Safety Study
1.2) Background
1.3) Context: Visions of Tall Timber
1.4) Principles of Fire Safety
1.5) Timber Building Fundamentals
1.6) Timber Fire Fundamentals
1) Overview and Background
REPORT: TASK 1 LITERATURE REVIEW
• 2.1) Overview
• 2.2) Testing Data on Timber Structural
Components in Fire
• 2.3) Ongoing Research Studies
• 2.4) Review of Fire Incidents in
Timber Structures
• 2.5) Review of Existing Design
Guidelines
• 2.6) Global Case Studies of
High-Rise / Tall Timber
Framed Buildings
1) Overview and Background
REPORT: TASK 2 GAP ANALYSIS
• 3.1) Overview
• 3.2) Structural and NonStructural Component
and Sub-System Fire Tests
• 3.3) Compartment Fire
Dynamics
• 3.4) Environment
• 3.5) Economics
• 3.6) Society
• 3.7) Prioritization
1) Overview and Background
SUPPORTING INFO: TALL BUILDING FIRE PROTECTION
• Report: “High Rise Building Fires”
• Fire Stats on U.S. High Rise Buildings
• For 2007 through 2011
1) Overview and Background
SUPPORTING INFO: TALL BUILDING FIRE PROTECTION
• Annual average: 15,400 fires; 46 civilian fatalities;
530 civilian injuries; $219M property damage
• Risk is lower in high rise buildings
• Reason: higher levels of built-in fire protection
(e.g., fire resistive construction, sprinklers)
Fire Hazards in Timber Buildings
and their Need for Sprinklers
AGENDA
1) Overview and Background
2) Timber Building Construction
3) Building Regulations for Timber
4) Timber Fire Performance
5) Knowledge Gaps & Future Direction
2) Timber Building Construction
EXAMPLES OF FEATURES AND CHARACTERISTICS
• Heavy timber frame products
- Engineered wood products
Glue laminated
wood (Glulam)
Laminated Veneer
Lumber (LVL)
Cross Laminated
Timber (CLT)
2) Timber Building Construction
EXAMPLES OF FEATURES AND CHARACTERISTICS
• Heavy timber frame products
- Composite wood products
Post-tensioned
timber
Timber-concrete
composite
2) Timber Building Construction
EXAMPLES OF FEATURES AND CHARACTERISTICS
• Heavy timber frame construction
- Panelized construction
2) Timber Building Construction
EXAMPLES OF EXISTING TIMBER BUILDINGS
• Historical examples
Yiangxian Pagoda,
China, 1056
Urnes Stakirke,
Norway, 1132
Leckie Building,
Vancouver, Canada, 1908
2) Timber Building Construction
EXAMPLES OF EXISTING TIMBER BUILDINGS
• Contemporary examples
- Post and beam construction
Life Cycle Tower One
Austria, 2012
Bullitt Center
Wood Innovation Design Centre
Seattle, WA 2013 Prince George, Canada, 2014
2) Timber Building Construction
EXAMPLES OF EXISTING TIMBER BUILDINGS
• Contemporary examples
- Panelized construction
Stadthaus
London, UK 2009
Via Cenni
Milan, Italy 2013
Forte Building
Melbourne, Australia 2013
2) Timber Building Construction
FEASIBILITY EXAMPLES OF TALL TIMBER BUILDINGS
40-story office building
CEI Architecture, 2013
Timber Tower
SOM, 2013
30-story high-rise
Michael Green
Architecture, 2012
Fire Hazards in Timber Buildings
and their Need for Sprinklers
AGENDA
1) Overview and Background
2) Timber Building Construction
3) Building Regulations for Timber
4) Timber Fire Performance
5) Knowledge Gaps & Future Direction
3) Building Regulations for Timber
INTERNATIONAL REGULATIONS
Maximum # of Stories
Country
Applicable Building Code
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**
* Indicates a height limit in addition to a maximum story limit
3) Building Regulations for Timber
U.S. REGULATIONS
Maximum # of Stories
Applicable Building Code
Sprinklered
Unsprinklered
2013 International Building Code
(IBC)
5*
4*
2012 National Fire Protection
Association (NFPA) 5000
6*
5*
* Number of heavy timber stories permitted
Fire Hazards in Timber Buildings
and their Need for Sprinklers
AGENDA
1) Overview and Background
2) Timber Building Construction
3) Building Regulations for Timber
4) Timber Fire Performance
5) Knowledge Gaps & Future Direction
4) Timber Fire Performance
CHARRING
• Well understood…
• Predictable…
• ~0.7mm/min (0.03 in/min)
4) Timber Fire Performance
EXAMPLES FROM LITERATURE REVIEW
• Timber Frame 2000 (TF 2000)
- Cardington, UK, 1999
- Fire resistance mid-rise
timber building
4) Timber Fire Performance
EXAMPLES FROM LITERATURE REVIEW
• Natural fire testing, Frangi and Fontana, 2005
- CLT structure
- Sprinklered vs. non-sprinklered
- Exposed wood vs. gypsum lining
Sprinkler protection
Gypsum board
lining
Exposed CLT
4) Timber Fire Performance
EXAMPLES FROM LITERATURE REVIEW
• Light timber assemblies
- Improved fire resistance with gypsum board layers
and thickness
- Design equations (Just, Schmid and Konig, 2010)
4) Timber Fire Performance
EXAMPLES FROM LITERATURE REVIEW
• CLT assemblies (Osborne, Dagenais, Benichou, 2012)
- Charring rate consistent with wood (~0.7 mm/min [0.03 in/min])
- Predictable behavior
- Improved performance with gypsum board protection
4) Timber Fire Performance
EXAMPLES FROM LITERATURE REVIEW
• Timber composite assemblies (O’Neill, 2012)
- Fire performance based on testing
- Up to 2-hour ratings for assemblies
4) Timber Fire Performance
EXAMPLES FROM LITERATURE REVIEW
• Environmental impact of fire protection (Wieczorek, Ditch &
Bill 2010)
- Tests demonstrate the positive impact of sprinklers:
o
Reduction in greenhouse gas emissions by 97.8%
o
Reduction in water usage between 50% and 91%
o
Significant improvement in water runoff quality
o
Reduction in fire-damaged contents
Fire Hazards in Timber Buildings
and their Need for Sprinklers
AGENDA
1) Overview and Background
2) Timber Building Construction
3) Building Regulations for Timber
4) Timber Fire Performance
5) Knowledge Gaps & Future Direction
5) Knowledge Gaps & Future Direction
TOPICS BEING CONSIDERED
• System level testing
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• e.g., with exposed steel
• Wood contribution to compartment fire
Composite assemblies
Connections
Delamination
Penetrations & firestopping
Economics
• Fire protection
• Life cycle costs
• Not being questioned
at this time: appropriate
sprinkler design
5) Knowledge Gaps & Future Direction
RECOMMENDATIONS FOR FUTURE RESEARCH
1) Fire testing of new and innovative
timber and hybrid solutions;
2) Full-scale / large-scale fire testing
of mock up tall timber frames;
3) Natural fire testing in full-scale /
large-scale tall timber frames;
4) Economic analysis to quantify
construction, operation and costs
of tall timber buildings; and
5) Emphasis on effective risk
communication and education
5) Knowledge Gaps & Future Direction
BUILDINGS UNDER CONSTRUCTION
• Additional challenges…
Contact Information:
Casey Grant, P.E.
Fire Protection Research Foundation
One Batterymarch Park, Quincy, MA USA 02169-7471
Phone: 617-984-7284 Email: cgrant@nfpa.org
FPRF Website: www.nfpa.org/foundation
www.NFPA.org/Foundation