Comparative fire performance of traditional lumber and engineered wood joists

This paper presents an evaluation of comparative fire resistance of traditional and engineered wood joists used in the construction of floor systems in residential housing. For developing this information, fire resistance experiments were carried out on four types of wood joists used in traditional and more modern residential construction. The test variables included type of wood joist, support conditions, and fire protection (insulation). Four types of wood joists, namely traditional lumber, engineered I-joist, castellated I-joist, and steel/wood hybrid joist, were considered in the study. The fire resistance tests were carried out by exposing the loaded wood joists to ASTM E-119 fire exposure. Data generated from fire resistance tests, including temperatures, displacements, and strains, is utilized to evaluate thermal and structural response of different types of wood joists. Results from these tests indicate that engineered joists have much lower fire resistance than traditional solid joist lumber.