Designing for Fire Protection

Expanding the possibilities of wood design
[ Page 4 of 9 ]            
Sponsored by Think Wood and the American Wood Council
Jeffrey B. Stone, Ph.D. Based on the Code Conforming Wood Design Series by the American Wood Council and International Code Council

Design Tools for Assemblies

Many sources are available for identification and selection of tested fire-rated assemblies. Generally, publications from recognized testing laboratories are the source for listings. Fire-rated wood-frame assemblies can be found in listings contained in such publications as:

▶   Underwriters Laboratories (UL) Fire Resistance Directory

▶   Intertek Testing Services’ Directory of Listed Products

▶   Gypsum Association’s Fire Resistance Design Manual

Fire-rated assemblies may also be selected from one of the prescriptive assemblies provided in IBC Section 721 based on ASTM E 119 or UL 263 test results, or by calculating an assembly’s capacity using IBC Section 722. The AWC publication Design for Code Acceptance (DCA) 3 – Fire-Rated Wood Floor and Wall Assemblies is also helpful in determining the fire rating of wood-frame wall and floor/ceiling/roof assemblies, and is available free at
www.awc.org/codes/dcaindex.html.

To permit use of “non-listed” assemblies, IBC Section 722.6 also recognizes a methodology for calculating the fire endurance of load-bearing and non-load-bearing wood assemblies (floor, wall, ceiling and roof assemblies) through a calculation methodology called Component Additive Method (CAM). CAM was developed in the early 1960s by the Fire Test Board of the National Research Council of Canada and validated through full-scale wood-framed assembly fire tests. 

CAM calculates fire endurance to equal the sum of:

▶   the contribution of the fire exposed membrane,

▶   the time to failure of the framing members, and, if applicable,

▶   additional protection due to the use of cavity insulation or reinforcement of the membrane.

Section 722.6 contains the procedures by which fire-resistance ratings of wood assemblies can be established using this calculation method. AWC’s publication DCA 4 – Component Additive Method (CAM) for Calculating and Demonstrating Assembly Fire Endurance provides a history of the method and an in-depth explanation of its use and application.

For the Jackson Hole Airport in Wyoming, designers chose wood because of its varied grain and color palette, as well as its ability to perform structurally under a variety of loading conditions. The inherent fire performance of heavy timber construction was vital in allowing the wood to be exposed. Winner of a 2015 WoodWorks Wood Design Award.

Courtesy: The American Wood Council

For the Jackson Hole Airport in Wyoming, designers chose wood because of its varied grain and color palette, as well as its ability to perform structurally under a variety of loading conditions. The inherent fire performance of heavy timber construction was vital in allowing the wood to be exposed. Winner of a 2015 WoodWorks Wood Design Award.

Architect: Gensler. Structural Engineer: Martin/Martin. Photo: Matthew Millman.

For the Jackson Hole Airport in Wyoming, designers chose wood because of its varied grain and color palette, as well as its ability to perform structurally under a variety of loading conditions. The inherent fire performance of heavy timber construction was vital in allowing the wood to be exposed. Winner of a 2015 WoodWorks Wood Design Award.

At the David & Lucile Packard Foundation company headquarters, wood was an important part of the strategy to achieve LEED Platinum certification.

Architect: EHDD. Structural engineer: Tipping Mar Structural. Photo: Jeremy Bittermann.

At the David & Lucile Packard Foundation company headquarters, wood was an important part of the strategy to achieve LEED Platinum certification.

 

[ Page 4 of 9 ]            
Originally published in Engineering News-Record

Notice

Academies