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Fire Endurance Test of Selected Residential Floor Constructions.



Jin B. Fang


A series of 10 load-bearing, wood-and steel-framed residential floors was evaluated for structural fire resistance in a fire endurance furnace. Nine wood-frame and one light gauge steel-frame, protected and unprotected floor/ceiling assembles, each measureing 3.05 x 2.44 m in size, were exposed from the underside to either the newly developed high-intensity, short-duration fire exposure or the standard ASTM E119 time-temperature curve. The fire endurance time based on the passage of flames to the unexposed face of the floor with unprotected wood joists varied from 6 to 9 minutes under the newly developed fire exposure and l6 to l8 minutes subject to the standard ASTM fire. Under the identical fire exposure, the exosed steel-framed floor failed in approximately 4.5 minutes compared to 9 minutes for the unprotected wood-frame floor. The wood floors evaluated in the test furnance had a shorter fire resistance period in comparison with those tested previously under room fire conditions probably due to faster charring rates and additional heat contirubution from the burning of combustible materials in the structure with the excess air present in the furnance.
NIST Interagency/Internal Report (NISTIR) -


fire endurance, fire tests, floors, flame through, furnace, joists, steels, wood


Fang, J. (1982), Fire Endurance Test of Selected Residential Floor Constructions., NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed April 19, 2024)
Created April 30, 1982, Updated February 19, 2017