Cross Laminated Timber (CLT) Gains Code Approval – New Opportunities for Wood in Non-Residential Structures

American Wood Council – Leesburg, Va. (November 12, 2012) – A proposed code change by the American Wood Council (AWC) to expand the use of cross laminated timber through the building code’s heavy timber construction classification has been approved by the International Code Council (ICC). The recently approved change will lead the way for new U.S. markets for this emerging wood product in non-residential buildings.

The ICC held its final action hearings Oct. 21-28, 2012 in Portland, Ore. where ICC members made final decisions on proposed language for the 2015 International Building Code (IBC). This now-approved code will be published in late-2014 and will be immediately available for jurisdictions to adopt in 2015. The IBC is one in a series of codes that is being updated by the ICC for 2015.

“Having worked closely with ICC code and fire officials, AWC was able to quickly answer questions raisedabout the proposal during the earlier ICC committee hearings in May,” said AWC Vice President of Codes and Regulations Kenneth Bland. “The strong support for the proposal shown by ICC members in Portland is validation of the ICC process when all stakeholders work together to maintain state-of-the-art codes.”

Prior to the hearings, as part of a project to produce a U.S. design manual forcross-laminated timber, AWC conducted a successful ASTM E119 fire endurance test on a CLT wall at NGC Testing Services in Buffalo, N.Y. The wall, consisting of a 5-ply CLT (approximately 7 inches thick), was covered on each side with a single layer of 5/8″ Type X gypsum wallboard. The wall was loaded to the maximum attainable by the test equipment, although it remained significantly below the full design strength of the CLT specimen. It was then exposed to a standard fire that reaches over 1800 degrees Fahrenheit in the first 90 minutes of exposure.

“While only seeking a 2-hour rating as required by the building code provisions, the test specimen lasted 3 hours 6 minutes. This may also open up additional possibilities in a few specialized locations where a 3-hr fire resistance rating might be required,” said AWC Vice President of Engineering Brad Douglas.

The test culminated nearly a month of intense planning and cooperation by the North American wood products industry to get the test run in advance of the recent ICC hearings.

For more information, contact Buddy Showalter at AWC (202-463-2769).