Mass Timber Construction

CLT primary applications are floors and decks. These are some of the more cost-effective structural building materials available. CLT has recently increased in popularity in the US and has been used most notably in Europe.

Cross lamination provides stability, strength and rigidity, making CLT a viable alternative to masonry, concrete or steel.

ICC: CHAPTER 6 TYPES OF CONSTRUCTION, 2015 International Building Code (IBC) | ICC Digital Codes (iccsafe.org)

Nov 30 2018 – New building codes in Washington State to allow mid and high-rise mass timber buildings up to 18 stories.

On Friday, November 30, the Washington State Building Code Council (SBCC) voted to approve code changes that will allow for the structural use of mass timber in buildings as tall as 18 stories. This makes Washington the first state in the nation to allow tall mass timber buildings into its building code, without pursuing an alternate method.

The previously set building code limited mass timber’s structural use to a maximum of 6 stories. Several mass-timber projects below 6 stories have been completed in Washington in recent years, including a set of pilot CLT classrooms funded by the State of Washington.

Washington’s code changes will update the 2015 International Building Code to incorporate all of the International Code Council’s Tall Wood Building Code proposals voted on in Richmond, VA in October, 2018. It will permit three new types of mass timber building construction — Type IV A, B, C — allowing for the structural use of mass timber at 18, 12, and 9 stories. The action comes after more than two years of comprehensive research and testing, including full-scale fire tests, completed by the International Code Council Ad Hoc Committee on Tall Wood Buildings.