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Fire Endurance of Open-Web Steel-Joist Floors With Concrete Slabs and Gypsum Ceilings.


pdf icon Fire Endurance of Open-Web Steel-Joist Floors With Concrete Slabs and Gypsum Ceilings. (2064 K)
Ryan, J. V.; Bender, E. W.

BMS 141; 19 p. August 23, 1954.

Keywords:

floors; joists; steels; concrete slabs; gypsum; ceilings; fire tests; plaster

Abstract:

The results presented were obtained in a program of 18 fire tests on open-web steel-joist floors, 16 of which were protected by ceilings of gypsum-perlite plaster on gypsum lath "furred" directly to the joists. Variables included plaster thickness, plaster mixes, spacing of furring channels, system of lath clips, reinforcing in the ceilings, and type floor slab. An acoustical plaster finish was applied to one ceiling. The range of fire endurances obtained, from 1 hour to 4 hours 26 minutes, was sufficient to cover the requirements for floors in many building codes. The importance of the ceiling's protective function was demonstrated in two tests without ceilings, in each of which failure occurred at 7 minutes.