I have had problems with grout cracking and water leakage in my
year-old tile shower. I have discovered that the builder used green
water resistant gypsum board instead of concrete board. He also used
steel edge trim pieces in a few places which are rusting under the
tiles and are not secured properly (I don't think they should even be
there).

The local building inspector told me that while the green stuff
"technically" meets city code, the department does NOT recommend its
use in showers. Because there is nothing in the code to prohibit its
use, they let it pass during the building inspection.

US Gypsum is ambiguous - it does recommend concrete board under
ceramic tile, but as far as the greenrock it just says

"Panels are not intended for use in areas subject to constant moisture
such as interior swimming pools, gang showers and commercial food
processing"

There is no mention of residential showers.

I wonder what approach I should use.... I am sure the builder will not
want to rip out the entire installation and replace the greenrock.

Comments? How hard should I fight this?

John

John Davies TLCA 14732
http://home.comcast.net/~johnedavies/
'96 Lexus LX450
'00 Audi A4 1.8T quattro
Spokane WA USA