Two layers 1” (25.4 mm) ToughRock® Shaftliner or DensGlass® Shaftliner inserted in H-Studs 24” (610 mm) o.c. Metal covered using 6” (152 mm) wide 1/2” (12.7 mm) DensArmor Plus® Fireguard C® panels or 1/2” (12.7 mm) ToughRock® Fireguard C® gypsum board.