Cement-based sheet material used as a substrate for tile on walls, floors, and counters. The material of choice in any wet area such as a kitchen or bathroom because it is unaffected by water. Also called cement board, wonder board, or green board.
A sacrificial board placed behind a workpiece during a cutting or shaping process. The backer board supports the wood to prevent chip-out as the blade or cutter exits the workpiece, shown right.