Dear Marcia:
If the waterproofing membrane is still in place and unscathed, the tiles or the grout cannot be the problem.
Needless to say, from here I can't even begin to guess what the cause of your leak could be.
There's a company called American Leak Detection (
www.americanleakdetection.com)
with franchises a little bit all over the country
.
You may consider inquiring with them.
Ciao and good luck,
Mauri
Article ID: 143
Created On: Fri, Jun 29, 2007 at 2:46 PM
Last Updated On: Fri, Jun 29, 2007 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]
Online URL: https://marblecleaning.org/knowledgebase/article.php?id=143