IBC Design 721.1(3) 10-1.1

2-Hour Fire Rated 1-1/2"-deep steel roof deck on steel framing.… — Ceiling of gypsum plaster on metal lath.…

IBC Table 721.1(3), Item 10-1.1: 1-1/2"-deep steel roof deck on steel framing. Insulation board, 30 pcf density, composed of wood fibers with cement binders of thickness shown bonded to deck with unified asphalt adhesive. Covered with a Class A or B roof covering.. Ceiling: Ceiling of gypsum plaster on metal lath. Lath attached to 3/4" furring channels with 0.049" (No. 18 B.W. gage) wire ties spaced 6" on center. 3/4" channel saddle tied to 2" channels with doubled 0.065" (No. 16 B.W. gage) wire ties. 2" channels spaced 36" on center suspended 2" below steel framing and saddle tied with 0.165" (No. 8 B.W. gage) wire. Plaster mixed 1:2 by weight, gypsum-to-sand aggregate. Minimum slab thickness — 2-hr: 1-7/8" · 1-hr: 1". Minimum ceiling thickness — 2-hr: 3/4" · 1-hr: 3/4". Prescriptive assembly from the adopted building code — see table footnotes for conditions.