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

Oregon Becomes First State To Legalize Mass Timber High Rises

by | Aug 17, 2018 | News

Thanks to a recent addendum to Oregon’s building code, the state is the first in the country to allow timber buildings to rise higher than six stories without special consideration.

Portland has become something of a hotbed for timber innovation as of late. Carbon12, PATH Architecture’s eight-story glulam and cross-laminated timber (CLT) tower with a steel core, recently became the country’s tallest timber building and was set to be surpassed by LEVER Architecture’s 12-story Framework. Alas, that project was put on hold due to mounting financial difficulties last month, but it seems the precedent that the project achieved in securing a building permit from the State of Oregon and City of Portland will live on.

The timber allowance comes courtesy of Oregon’s statewide alternate method (SAM), a state-specific program that allows for alternate building techniques to be used after an advisory council has approved the “technical and scientific facts of the proposed alternate method.” The allowance comes after the International Code Council (ICC)–the nonprofit group that Oregon models its building codes after–established the ICC Ad Hoc Committee on Tall Wood Buildings in 2015 to explore the benefits and challenges of using timber in tall buildings.

A Committee Action Hearing was held in April of this year, where the Ad Hoc Committee, made up of code experts, stakeholders, and industry members presented their findings. All 14 of the committee’s suggestions were adopted, introducing standards and best practices for fireproofing, the load-bearing potential of CLT and heavy timber, water resistance, sealing, seismic ratings, and more.

Three new building classifications were introduced as a result: Type IV A, timber buildings permitted up to 18 stories and 270 feet tall, Type IV B, timber buildings with a maximum height of 12 stories and 180 feet, and Type IV C, which is permitted to rise nine stories and 85 feet tall at maximum. The shortest of the timber typologies is allowed to use exposed structural timber as an interior finish, whereas the tallest, type A, must enclose all exposed surfaces and include a three-hour fire-resistance rating for the structural elements.

Read more on this from The Architects Newspaper at https://archpaper.com/2018/08/oregon-legalize-mass-timber-high-rises/.