Water resistant greenboard sheetrock should not be used for walls that will be subjected to heavy amounts of moisture. This includes but is not limited to, shower stalls and tub enclosures. Greenboard is water resistant but not water proof and will disintegrate if it is exposed to excessive amounts of moisture. It no longer is approved for use (ANSI A108) as a wet substrate. Depending on moisture conditions, this product is acceptable for use as a ceramic tile substrate in residential backsplashes and bathroom wainscotings. Wood studs should be spaced a maximum of 16" on center. Ceiling studs should be spaced a maximum of 12" on center if ceramic tile is to be applied. The use of a vapor barrier is not recommended for this type of product.
We recommend the use of 1/2" thick cementitious ceramic tile backerboards for use in bathrooms for tub and shower enclosure walls. Wood studs should be spaced a maximum of 16" on center.
In high moisture areas, a moisture barrier (such as 15 pound roofing felt) should be installed over wall studs before installing the ceramic tile backerboard to the wall. |