The American Wood Council (AWC) has released an updated Technical Report (TR) 10, Calculating the Fire Resistance of Wood Members and Assemblies.
“The emergence of mass timber as a competitive product in the construction marketplace has increased designers’ interest in the fire performance of mass timber. Recognizing that increased interest, the principal changes to this edition provide new examples and background on mass timber members and assemblies,” said Brad Douglas, AWC vice-president of engineering. “TR10 will assist in the design of efficient and building-code-compliant loadbearing wood members and assemblies by providing background information, examples of calculations, and end-use tables for a variety of structural wood products.”
Primary revisions to TR10 include the following.
- Expansion of design provisions for calculating the contribution of gypsum board protection in Chapter 4, “Design Procedures for Exposed and Protected Wood Members.” The revised provisions provide information for calculating both the increased structural fire resistance and thermal resistance provided by various types of protection.
- Calculation of thermal separation times were updated in Example 5 (Exposed Cross-Laminated Timber floor design) and Example 6 (Exposed Cross-Laminated Timber wall design) to more closely estimate the benefits of protection.
- Example 8 (Protection of Steel Ledger Connection) and Example 9 (Protection of Beam-Column Connection) were updated to include information on use of gypsum board as required to protect connections of mass timber members in the new Type IV-A and IV-B buildings permitted in the 2021 International Building Code (IBC); and a new Example 10 (Protection of Tension Splice Connection) was added at the request of designers seeking an example of a completely concealed mass timber connection.