Room-Corner Tests with Exposed Timber

Fire experiments were conducted to observe the effect of varying amounts of exposed timber wall and ceiling assemblies in a standard room-corner fire test. The standard test, NFPA 286 (Fire Tests for Evaluating Contribution of Wall and Ceiling Interior Finish to Room Fire Growth) is based on a room with a door opening at the front and a gas burner located against a back corner. Pass or fail criteria for flashover are provided for the test, with the test lasting up to a maximum of 15 min. Three experiments were conducted that comply with the 2021 International Building Code for amount of exposed mass timber. For each experiment, the propane burner profile was identical. Instrumentation used during the experiments included thermocouples, a heat flux transducer, and a heat release rate exhaust hood. Based on the time to flashover criteria in the standard, flashover was not observed in any of these three tests.