A succession of more water-resistant and waterproof backerboards now gives the industry more faith in long lasting installations of ceramic tile and stone in wet areas. Upon its introduction, the backer board we now know as a Cementitious Backer Unit (CBU) almost immediately became the backer unit of choice.
Another improvement over WR gypsum board was accomplished by the introduction of Coated Glass Mat Water-Resistant Gypsum board. This product complies with ASTM C-1178 and appears in the 2003-2004 Tile Council of America (TCA) Handbook in detail W 245-03 and as a new detail for floors in detail F 151-03.