As a tile backing board, cement board has better long-term
performance than paper-faced gypsum core products because it will
not mold, mildew or physically break down in the continued presence
of moisture or leaks. Cement board is not actually waterproof, but
it is highly resistant to absorbing moisture and has excellent
drying properties. In areas continually exposed to water spray
(i.e. showers) a waterproofing barrier is usually recommended
behind the boards or as a�trowel-applied
product to the face of the boards behind the finish system.
