3/4"-4'X8' T&G ORIENTED STRAND BOARD | Every Weyerhaeuser Edge panel is strong, stiff, and stable-it's manufactured flat, installs flat, stays flat, and has been engineered to precise specifications to resist problems like cupping, warping, and sagging. With self-gapping tongue-and-groove edges, Weyerhaeuser Edge panels make installation fast and easy. Apply panels perpendicular to support joists. Use appropriate fasteners at the recommended schedule and gap panels 1/8" on the ends of each panel. All edges are sealed for moisture and weather resistance. Each sheet is Association Grade stamped and also carries the span ratings. Check the Building Code for the application required in your area. Other manufacturers are substituted at times, Weyerhaeuser is our main supplier.