1 inch thick Durable pehd sheet for outdoor-Cus-to-size HDPE Apr 27, 2022 · Sheet the walls like you would a floor by staggering the joints. Remember to leave a 1/8 inch gap between the sheets, I just use a 3 ¼ inch nail to space the sheet rrectly. Nail or screw the sheeting 8 inches on the studs and screw or nails the joints to 6 inches.