In carpentry, what is a "backer board" used for?

A backer board is specifically designed to provide a stable and moisture-resistant surface for the installation of tile and other finishes in walls, particularly in areas that may be exposed to water, such as bathrooms and kitchens. This type of board acts as a substrate that helps to ensure the tiles adhere properly and stay in place over time, thereby preventing issues such as cracking or peeling that can occur if installed directly over drywall or other unsuitable surfaces.

The use of backer board is crucial in construction and remodeling projects where durability and water resistance are priorities. For instance, cement backer board is commonly used in wet areas, as it does not deteriorate when exposed to moisture. This selection enhances the longevity and quality of the finished surface, making it essential for tile installations.

While other options mention supports or coverings, they do not align with the specific function of a backer board in the context of flooring or wall tile applications. Thus, backer board’s primary purpose is to ensure a robust foundation for tiles, which is critical to the integrity of the finished project.