Plywood and Panels

Plywood consists of layers of wood veneer laminated together with the grain of the wood alternating direction on each layer. Plywood is used in a variety of applications. The two biggest uses are for sheathing and underlayment. Sheathing is literally the skin over framing members, either joists, studs or rafters. Underlayment is used as a secondary layer over a base layer to add a stiff flat surface for finish materials such as flooring or a tile countertop.