In order for wood structures to rise above six stories without special building official permission, changes to the International Building Code are needed. In cooperation with the American Wood Council, the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), and the Forest Service’s State and Private Forestry, Forest Service researchers at the agency’s Forest Products Laboratory in Madison, Wisc., recently recreated five fire scenarios in a two-story, full-scale test building constructed with cross laminated timber (CLT). They shared the results with the members of the International Code Counci's ad-hoc committee on Tall Wood Buidings. The test building, constructed at the ATF’s Fire Research Laboratory in Beltsville, Md., consisted of two identical, furnished one-bedroom apartments. The scenarios tested various arrangements of exposed and unexposed CLT with open doors between living and sleeping areas. Additionally, automatic sprinkler system effectiveness was evaluated.
The tests demonstrated that even with exposed CLT, it was possible to construct CLT apartments that could survive a complete burnout of the contents even with exposed CLT.