U.S. Forest Service Celebrates CLT During Forest Products Week

by | Oct 24, 2018 | News

From October 21-27, 2018, we celebrate the value of America’s forests and recognize how vital they are to our well-being and national prosperity during National Forest Products Week. This week is recognized each year by a Presidential proclamation. At the USDA Forest Service, we work year round to create new opportunities for wood products that contribute to diversified rural economies and support sustainable forest management.

By supporting forest products markets, we have the opportunity to create safer communities by reducing wildfire risk, supporting rural economic development, and contributing to a more sustainable building sector. The Forest Service is working to develop the U.S. market for cross-laminated timber, or CLT, and other mass timber technologies.

CLT is a made from several layers of dried lumber boards stacked in alternating directions, glued and pressed to form rectangular panels. These panels have exceptional strength and stability and can be used as floors, walls and roofs in building construction, replacing or used along with traditional building materials such as concrete and steel. In fact, the International Code Council is examining whether or not tall wood buildings up to 18 stories will be included in the 2021 International Building Code. A final decision will be made later this year.

The state of Oregon has already adopted the proposed provisions for the International Code Council under its Statewide Alternate Method, and Washington State legislation already embraces mass timber construction. The U.S. Department of Defense is already using CLT in some of its on-base housing because of the incredible resiliency of the materials and their resistance to explosive forces.

We are on the precipice of major momentum in the marketplace with mass timber, with four factories in production, including two making architectural grade CLT; five factories coming online (either under construction or just completed); and three more factories recently announced in eight states. Compounded with the upcoming code decisions, we expect to see many more mass timber and CLT buildings in the near future.

From the USDA: https://www.usda.gov/media/blog/2018/10/22/forest-service-celebrates-cross-laminated-timber-during-forest-products-week

U.S. Forest Service: Build Better, Stronger, Faster With CLT

by | Apr 5, 2017 | News

The U.S. Forest Service is working to build markets for innovative forest products. One of these products, cross-laminated timber, also known as CLT, offers an opportunity for raising tall buildings with wood, opening up a completely new market for wood products.

And there’s tremendous opportunity to increase the market share for wood-based construction. Because of its high strength, CLT is an advantageous alternative to traditional building materials such as concrete, masonry, and steel. Because CLT panels resist compression, they are well-suited for building multistory structures, especially mid-rise buildings. Made from layers of dried lumber boards, stacked in alternating direction at 90-degree angles, glued and pressed to form solid panels, CLT has exceptional strength and stability and can be used as walls, roofs, and floors.

Additionally, CLT is highly resilient to fire, earthquakes, and even explosions. In fact in a recent series of live blast tests, CLT passed with flying colors. An examination of the results showed that the CLT structures suffered less degradation than expected and might outlast concrete and steel.

In terms of fire, CLT is like using a large log to start a campfire—it doesn’t ignite easily. And when it does burn, a char layer forms on the outside, protecting the inside and allowing the wood panel to maintain its structural integrity during fire scenarios.

Researchers have conducted extensive seismic testing on CLT and found that the panels perform exceptionally well in multi-story applications. When a seven-story CLT building was tested on the world’s largest shake table in Japan, it survived 14 consecutive earthquake simulations with almost no damage.

From the USDA: https://www.usda.gov/media/blog/2017/04/04/build-better-stronger-faster-clt