IBC Design 721.1(2) 16-1.1

1-Hour Fire Rated Exterior walls rated for fire resistance from the inside only in accordance with Section 705.5 — 2" x 4" wood studs at 16" centers with double top plates, single…

IBC Table 721.1(2), Item 16-1.1 (q) (Exterior walls rated for fire resistance from the inside only in accordance with Section 705.5): 2" x 4" wood studs at 16" centers with double top plates, single bottom plate; interior side covered with 5/8" Type X gypsum wallboard, 4' wide, applied horizontally unblocked, and fastened with 2-1/4" Type S drywall screws, spaced 12" on center, wallboard joints covered with paper tape and joint compound, fastener heads covered with joint compound. Exterior covered with 3/8" wood structural panels, applied vertically, horizontal joints blocked and fastened with 6d common nails (bright)—12" on center in the field, and 6" on center panel edges. Cavity to be filled with 3-1/2" mineral wool insulation. Rating established for exposure from interior side only. Minimum finished thickness (face-to-face) — 1-hr: 4-1/2". Prescriptive assembly from the adopted building code — thicknesses are code minimums, see table footnotes for conditions.