Does Cement Board Need Waterproof

Concrete backer-board, once commonly referred to in the field by the brand name Wonderboard(r), is a cement product designed as a sheathing material for walls and floors. … Most concrete backer-boards on the market today are not water-resistant, but all are waterproof.

Is cement board waterproofing necessary?

Contrary to popular thought, tile and grout are not waterproof, and some moisture will penetrate even if sealant is used. … However, if you choose to use concrete backerboard, which is much stronger and more durable than gypsum board, a water vapor membrane must be placed underneath it or a sealant applied on top of it.

Can you shower with just cement board?

There are several acceptable applications of cement board in the shower. All applications pair up the tile board with some kind of waterproofing material, whether a liquid membrane, plastic sheeting, an uncoupling membrane like Schluter Kerdi, or a board that is already faced with waterproofing.