ASK THE EXPERTS QUESTION I am in need of your expertise! We received photos of an instal- lation of glass mosaic tile that did not exactly go smoothly. A client wanted someone to come check it on site to see if it is an installa- tion issue, so I am in need of some industry advice. Could you speak to the photos below? ANSWER It appears from these photos that this installation suffers from a lack of proper grout joint / sheet align- ment and possibly inadequate sub- strate flatness, (but that could be an optical illusion). Was this tile manufactured to meet the standards and toleranc- es of ANSI A137.2? This is the American standard specification for the manufacture of glass tile. It and ANSI A137.1 (for the manu- facture of ceramic tile) include the manufacturer quality control and test requirements for sheet-mount- ed mosaic tiles. If these mosaics were not mounted to meet the specifications found in these stan- Sponsored by Ask the Experts Q&As are culled from member inqui- ries to NTCA’s Technical Support staff. To become a member and make use of personal, targeted answers from Technical Support staff to your installation ques- tions, contact Jim Olson at jim@tile-assn.com. 22 TileLetter | November 2018