Glass Tile Selection and Installation Guide – TCNA 2016 Handbook
The recommended substrates for glass tile installations are similar to ceramic tile installations, however, extra attention should be given to substrate stability, rigidity, and preparation. Substrates should be sufficiently flat to allow uniform coverage and avoid excessive mortar thickness. Glass tile is generally more vulnerable to crack propagation than ceramic tile. The glass manufacturer may recommend use of a crack isolation membrane for large format glass tiles.
Mortars specifically formulated for glass tile must be used. When installed over an impervious substrate, setting materials may take longer to cure. Some manufacturers may require use of a specific mortar.
Grout recommendations for glass tile vary based on aesthetics and joint size. Most manufacturers recommend unsanded grout to prevent scratching. Because glass tile is impervious, additional setting time may be necessary to allow the grout to firm prior to cleaning.
Make sure to check your TCNA Handbook or ANSI standards when installing glass tile.