IBC Design 721.1(2) 15-1.16

2-Hour Fire Rated Exterior or interior walls — 2" x 6" wood studs at 24" centers with double top plates, single…

IBC Table 721.1(2), Item 15-1.16 (q) (Exterior or interior walls): 2" x 6" wood studs at 24" centers with double top plates, single bottom plate; interior and exterior side covered with two layers of 5/8" Type X gypsum wallboard, 4' wide, applied horizontally with vertical joints over studs. Base layer fastened with 2-1/4" Type S drywall screws, spaced 24" on center and face layer fastened with Type S drywall screws, spaced 8" on center, wallboard joints covered with paper tape and joint compound, fastener heads covered with joint compound. Cavity to be filled with 5-1/2" mineral wool insulation. Minimum finished thickness (face-to-face) — 2-hr: 8". Prescriptive assembly from the adopted building code — thicknesses are code minimums, see table footnotes for conditions.