We are working with a contractor and we are beginning to doubt he has the expertise to do the job correctly. We are re-doing a shower. The walls are travertine. The floor is a matching "river stone". Our initial concern developed because in just a couple of weeks the grout begin popping out of the grout lines. He had butted the tiles together and just filled the bevel. When we begin investigating this we came across the fact that some adhesives cause tile discoloration. This was news to him.
Bottom line does anybody know where we can go and get official recommendations or guidelines. Dahl Tile ( who we purchased the tile from) has been silent to our requests and we can not find a "Tile Setters of America" type website that might have "industry standards" for our situation.