IBC Design 721.1(3) 12-1.1

2-Hour Fire Rated 1-1/2" deep steel roof deck on steel-framing… — Gypsum-vermiculite plaster on metal lath…

IBC Table 721.1(3), Item 12-1.1: 1-1/2" deep steel roof deck on steel-framing insulation of rigid board consisting of expanded perlite and fibers impregnated with integral asphalt waterproofing; density 9 to 12 pcf secured to metal roof deck by 1/2"-wide ribbons of waterproof, cold-process liquid adhesive spaced 6" apart. Steel joist or light steel construction with metal roof deck, insulation, and Class A or B built-up roof covering.. Ceiling: Gypsum-vermiculite plaster on metal lath wire tied at 6" intervals to 3/4" furring channels spaced 12" on center and wire tied to 2" runner channels spaced 32" on center. Runners wire tied to bottom chord of steel joists. Minimum slab thickness — 2-hr: 1". Minimum ceiling thickness — 2-hr: 7/8". Prescriptive assembly from the adopted building code — see table footnotes for conditions.