I am remodeling a bathroom and planning to use a cement- based tile backer-board. Should I consider using a waterproof membrane as well even though the backer-board is cement?
The confusion seems to be associated with the word cement. Although cement is not typically affected by water exposure, cement is not waterproof. The typical tile backer-board is thick. Water can pass through many of the backer-boards leaving the board and tile surface structurally intact but, over time, can cause extensive damage to the walls, floors and ceilings behind or around the tile installation. Applying TexRite HydroRite as a waterproof membrane to the backer-board before the tile or stone installation is a good practice, especially treating the joints, the weakest area of the backer-board installation. CAUTION: Always check the local building codes for guidelines on waterproofing and vapor barriers, when remodeling bathroom areas.
