IBC Design 721.1(3) 13-1.1

1-Hour Fire Rated Double wood floor over wood joists spaced 16" on… — Gypsum plaster over 3/8" Type X gypsum…

IBC Table 721.1(3), Item 13-1.1: Double wood floor over wood joists spaced 16" on center.. Ceiling: Gypsum plaster over 3/8" Type X gypsum lath. Lath initially applied with not less than four 1-1/8" by No. 13 gage by 19/64" head plasterboard blued nails per bearing. Continuous stripping over lath along all joist lines. Stripping consists of 3"-wide strips of metal lath attached by 1-1/2" by No. 11 gage by 1/2" head roofing nails spaced 6" on center. Alternate stripping consists of 3"-wide 0.049" diameter wire stripping weighing 1 pound per square yard and attached by No. 16 gage by 1-1/2" by 3/4" crown width staples, spaced 4" on center. Where alternate stripping is used, the lath nailing shall consist of two nails at each end and one nail at each intermediate bearing. Plaster mixed 1:2 by weight, gypsum-to-sand aggregate. Minimum ceiling thickness — 1-hr: 7/8". Prescriptive assembly from the adopted building code — see table footnotes for conditions.