IBC Design 721.1(2) 13-1.2

2-Hour Fire Rated Noncombustible studs—interior partition with gypsum wallboard each side — 0.018" (No. 25 carbon sheet steel gage) channel-shaped studs 25" on…

IBC Table 721.1(2), Item 13-1.2 (Noncombustible studs—interior partition with gypsum wallboard each side): 0.018" (No. 25 carbon sheet steel gage) channel-shaped studs 25" on center with two full-length layers of 1/2" Type X gypsum wallboard (e) applied vertically each side. First layer attached with 1"-long, No. 6 drywall screws, 8" on center around the perimeter and 12" on center on the intermediate stud. Second layer applied with vertical joints offset one stud space from first layer using 1-5/8"-long, No. 6 drywall screws spaced 9" on center along vertical joints, 12" on center at intermediate studs and 24" on center along top and bottom runners. Minimum finished thickness (face-to-face) — 2-hr: 3-5/8 (d)". Prescriptive assembly from the adopted building code — thicknesses are code minimums, see table footnotes for conditions.