Comparative fire performance of traditional lumber and engineered wood joists

Purpose This paper aims to present an evaluation of comparative fire resistance on traditional and engineered wood joists used in the construction of floor systems in residential housing. Design/methodology/approach Fire resistance experiments were carried out on four types of wood joists, namely, traditional lumber, engineered I-joist, castellated I-joist and steel/wood hybrid joist, used in traditional and modern residential construction. The test variables included type of wood joist, support conditions and fire protection (insulation). Findings Results from these tests indicate that webs of engineered I-joists and castellated I-joists are highly susceptible to fire, and failure generally occurs through the burn-out of the web. In addition, engineered I-joists have much lower fire resistance than traditional solid joist lumber. The application of an intumescent coating on an engineered I-joist significantly enhances its fire resistance and yields a similar level of fire resistance as that of a traditional lumber joist. Originality/value The presented fire tests are unique and provide valuable insight (and information) to the behavior and response of four types of wood joists when subjected to gravity loading and fire conditions. </jats:sec