Just when we were getting used to porcelain tile products, along comes an old product with a new focus.
Growth in the glass tile segment of the tile industry is nothing short of stellar. I have been around awhile, and am always continually amazed at the creativity in the tile industry. I struggle to think of any product market, cars, furniture, or even toys, that is blessed with the creative talent and dedication as good as those who work in the design part of the tile industry. This is readily apparent in the current glass tile offerings. But, as many of you know, my dedication is on the installation side of the tile equation so this is not an article about how to sell glass. Rather, it is an article about how to keep your money when you're installing glass tile.
Glass tile has been installed successfully using mortar beds for hundreds of years and mortar is still the preferred method of installation by trained industry professionals. However, today's building methods and practices often don't allow the opportunity for conventional (mud or mortar) installations and the qualified labor available for this type of work has always been in short supply. Today we are in a thinset or thinbed world where we bond directly to substrates. Glass tile can be successfully installed using these methods by experienced tile setters over cementious or dimensionally stable surfaces.
These standards contain detailed guidelines for successful installations established by many years of field experience and intensive testing by independent laboratories. As with any ANSI method, manufacturers' written instructions and local codes always prevail. Certain types of products, geographical areas, or construction practices may dictate additional considerations not addressed in the standards recommendation. Its intended use is a minimum guideline for successful installations.
There are many additional recommendations contained in the Tile Council of America Handbook under method EJ 171. These joints can be very disturbing to the end user if they are not aware of the necessity. On more than a few occasions I have been accused of trying to destroy the "look" sought after and paid for before I got on the job. Please educate yourself and the sales people in this critical performance area. There are many areas an installer can deal with on the job; destroying the dream sold to the customer by the salesperson is not one of them. The caulk or sealant needed for these joints should be made part of the sale and matched to the grout as closely as possible. This requires advanced ordering and consideration during the grout selection process. Another possibility is a premade movement joint offered by many manufacturers. You can often turn these into design statement making it a desirable part of the installation. We did it for years; it works.
Grout, as we have come to expect, also varies by product. Recommendations are based on joint with and the properties of the tile. Some glass tile scratches easily; most does not. Check for recommendations on either sanded or unsanded. This will also determine joint width as unsanded can not be used in a grout joint wider than 1/8-inch. Another serious consideration is drying time. Joints are better left ungrouted until the thinset has reached an initial cure. This can vary widely with type of thinset and environmental conditions. The bond to glass is very fragile during the initial drying stage and should not be disturbed until it has achieved adequate strength. With smaller tile, such as 1-by-1 or 2-by-2, a few days may be all that is necessary. However, as the tile gets larger, the drying time increases. Given ideal environmental conditions, you should think in terms of days, not hours for larger tile. Additional time is required for low temperatures or high humidity. Sealing glass tile serves no purpose. Grout can always benefit from a sealer but once again, drying time can be extended before the application of grout sealers.