Backerboard is the generic term for the sheet material that's installed beneath ceramic tile. Although backerboard has been around for 25 years, it didn't hit the mainstream until the 1980s. Before then, tile was set on a mortar bed or on water-resistant drywall. A mortar bed is still the Cadillac of tile backers, but mortar beds are expensive to install, and it's hard to find someone who knows how to do them. As a result, they're usually reserved for high-end work. Water-resistant drywall, called green board because of its green facing paper, costs much less and can be hung by the drywallers. But while green board resists water better than ordinary
