Two layers of 1/2” (12.7 mm) ToughRock® Fireguard C® gypsum board or 1/2” (12.7 mm) DensArmor Plus® Fireguard C®. Base Layer: Screw-attached to 1-5/8” (41 mm) steel studs located at corners of heavy steel W14 x 233 (metric W360 x 347) column with 1” (25 mm) Type S screws 24” (610 mm) o.c. Face Layer: Attached with 1-5/8” (41 mm) Type S drywall screws 12” (305 mm) o.c. into studs. 1” (25 mm) corner bead applied each corner with 1-3/8” (35 mm) 4d coated nails 12” (305 mm) o.c.
