Fire Endurance of Open-Web Steel-Joist Floors With Concrete Slabs and Gypsum Ceilings.
Fire Endurance of Open-Web Steel-Joist Floors With
Concrete Slabs and Gypsum Ceilings.
Ryan, J. V.; Bender, E. W.
BMS 141; 19 p. August 23, 1954.
floors; joists; steels; concrete slabs; gypsum;
ceilings; fire tests; plaster
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.