IBC Design 721.1(3) 28-1.1

2-Hour Fire Rated Wood I-joist (minimum I-joist depth 9-1/4" with a… — Base layer of 5/8" Type C gypsum wallboard…

IBC Table 721.1(3), Item 28-1.1: Wood I-joist (minimum I-joist depth 9-1/4" with a minimum flange depth of 1-1/2" and a minimum flange cross-sectional area of 2.25 square inches; minimum web thickness of 3/8") @ 24" o.c. Unfaced fiberglass insulation or mineral wool insulation is installed between the I-joists supported on the upper surface of the flange by stay wires spaced 12" o.c.. Ceiling: Base layer of 5/8" Type C gypsum wallboard attached directly to I-joists with 1-5/8" Type S drywall screws spaced 12" o.c. with ends staggered. Minimum 0.0179"-thick hat-shaped 7/8-inch furring channel 16" o.c. (channels doubled at wallboard end joints), placed perpendicular to the joist and attached to each joist by 1-5/8" Type S drywall screws after the base layer of gypsum wallboard has been applied. The middle and face layers of 5/8" Type C gypsum wallboard applied perpendicular to the channel with end joints staggered. The middle layer is fastened with 1" Type S drywall screws spaced 12" o.c. The face layer is applied parallel to the middle layer but with the edge joints offset 24" from those of the middle layer and fastened with 1-5/8" Type S drywall screws 8" o.c. The joints shall be taped and covered with joint compound. Minimum slab thickness — 1-hr: Varies". Minimum ceiling thickness — 2-hr: 2-3/4". Prescriptive assembly from the adopted building code — see table footnotes for conditions.