Oriented Strand Board

Oriented strand board (OSB) is an engineered wood product that's made with flakes or large chips of wood. The panels are formed from layers glued together with their strands at 90-degree angles to one another. The cross-orientation of the layers adds strength to the panels and makes OSB well-suited for use as a structure board in sheathing and underlayment. It can be cut with all power saws but since it's a structure board, it's not suited to shaping, sanding or other milling operations.