Weather-Resistant Sheathing. Drywood is a structural wall and roof panel with an integral weather barrier that eliminates the need for roofing felt, waterproof membranes, or housewrap. Joints are sealed with a 4-inch-wide asphalt-based seam tape (sold separately). The sheathing can support shingles, slate, tile, wall veneers, and siding. Standard offerings include 4x8 OSB panels in 1/2-inch and 5/8-inch thicknesses for $20 and $25 respectively. Larger and thicker sizes can be special-ordered. Drywood Products, 309/303-0514, drywoodproducts.com