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Fire Safety Challenges of Tall Wood Buildings – Phase 2: Task 3 - Cross Laminated Timber Compartment Fire Tests



Joseph Su, Pier-Simon Lafrance, Matthew S. Hoehler, Matthew F. Bundy


This study quantifies the contribution of cross laminated timber (CLT) building elements to compartment fires and characterizes the effect of gypsum board on delaying or preventing involvement of the CLT in the fire under varied ventilation conditions. Six compartments (9.1 m long x 4.6 m wide x 2.7 m high) were assembled out of prefabricated CLT panels. Each panel was factory assembled using five plies of 35 mm thick lumber for a total thickness of 175 mm. A polyurethane adhesive was used to hold the plies together. The compartment had a rough opening in Wall W2 (front) of 1.8 m wide x 2.0 m high in four tests and 3.6 m wide x 2.0 m high in two tests. The inside of the compartments was fully or partially lined using multiple layers of 15.9-mm thick Type X gypsum board. Real residential contents and furnishings were used to provide a fire load density of 550 MJ/m2. The fire tests were conducted without sprinklers and without firefighting intervention. Test 1-1 served as a baseline for the tests with the 1.8 m x 2.0 m rough opening in the front wall of the structure (Wall W2). Three layers of the gypsum board were used to cover the CLT walls and ceiling in Test 1-1 so that the CLT would neither contribute to the fire nor develop char during the test. Test 1-2 served as a baseline for the tests with the 3.6 m x 2.0 m rough opening in the front wall of the structure (Wall W2). An exposed wall (W1) was tested in both ventilation configurations (Test 1-3 and Test 1-5). Test 1-4 and Test 1-6 involved an exposed ceiling and a combination of exposed ceiling and wall, respectively, with the 1.8 m x 2.0 m rough opening.
Fire Protection Research Foundation


Fire, Cross Laminated Timber, Compartment Fire
Created February 14, 2018, Updated April 27, 2020