I am doing a remodel and the drywall guy left the shower stud bays uncovered
so the tile guy put up paper and cement and is ready to tile. In the
kitchen and over the bathroom vanities, he drywalled it. Is it ok to have
the tile guy either put up lath and cement or wonder board on top of the
drywall as a backing for the tile. He says he doesn't want to rip it out if
he doesn't have to. Some guy in a store recommended a sealer ... Red Guard
and said if you put that on the drywall (green board) it helps the cement or
thinset to bond. The tile guy says that is very expensive and not
necessary. He also says that good caulking between the vanities and wall is
good for water protection. He says that bitchitaneing that joint is also
not necessary. I am afraid that water that seeps through a failed grout
line can make its way to the drywall behind and cause problems. Any help or
advice would be appreciated.
I don't like to put tile on dry wall, or green board, in a kitchen or
bathroom situation if there is even a remote chance of moisture (or high
humidity) getting to it.
Durock over existing drywall will work and would be my preference if you
can tolerate the extra thickness. I know of no way to truly seal gypsum
Even in areas where no water is anticipated I like to cut the drywall
back about 1/2 to 5/8 inch above any counter or other horizontal surface
and let the tile extend down to the counter with no drywall behind it
for that distance. That way if any water gets under the tile (and it
will...sometime) there is no gypsum board to get wet and swell.
Bithuthene is an asphalt derived mastic that is used to apply a water
proofing membrane, usually on roofs or sometimes over concrete
exteriors. I'd not use it in a kitchen or bath.
Michael Roback wrote:
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