Plywood

Plywood for solar panels

5/8 plywood as a minimum, depending on local codes/recommendations. Waterproof underlayment (Ice and Water) is just more expensive. Doesn't matter much once you poke a bunch of holes in it. Use Sashco Big Stretch. . Plywood is an engineered wood product that you can use for a range of different projects — from outdoor construction to building furniture and other décor items. Solarply installs like traditional sheathing but it has a foil coating on 1 face which reduces up to 97% of the radiant heat transfer from the roof to the attic. I'd go cement board It wouldn't be. . A house protected by Solarbord Radiant Barrier Sheathing has a head start on comfort. [PDF Version]