Homeowners and interior design professional who want a fashion-forward, fresh look select glass tile accents more frequently than ever. Glass tile harmonizes with either traditional, transitional or contemporary architecture, adding a splash of style. For years, glass tile was only used for accent and trim pieces, with ceramic tile filling the field; there was not much thought given to the installation materials, which were generally the same as those used for the ceramic tile. Modern design trends continue to push the envelope with glass tile, moving beyond the traditional accent pieces – glass tile is now being used as field tile with sizes 12″ x 12″ or larger, and with these new marble tiles come new challenges.
Ensure color consistency behind glass tile. Since glass can be the sole material in an installation, it is essential to choose a bonding mortar that meets its unique demands. In most cases, the color of the thin-set mortar was not an issue when installing opaque ceramic tile. But with clear and translucent glass, the mortar appears through the tile: if the color varies in the mortar, it will in the glass tile too.
To eliminate variations across a glass tile installation, choose a glass tile mortar with a bright white shade that is controlled to a consistent standard color. The color consistency will ensure a uniform appearance on the face of the glass tile, even in large installations that require multiple batches of mortar. As an added bonus, the bright white shade of the mortar can enhance the color of the clear or translucent glass tile.
Eliminate mortar voids. A typical ceramic tile installation involves spreading a thin-set mortar on the surface with a notched trowel, then pressing the ceramic tile into the mortar to collapse the ridges and improve contact between the tile and mortar. Unfortunately, this practice can leave many voids in the mortar behind the tile. While this would not be a concern with opaque ceramic tile, the randomly distributed air pockets or voids may be visible through clear or translucent glass.
The mortar should still be spread with a notched trowel onto the substrate, but it should also be spread (back-buttered) in an even, thin film onto the back of the glass tile. Now, when the two mortared surfaces are pressed together, the back of the tile is already covered, so any remaining voids from the mortar ridges are hidden and do not show through the glass tile. Keep in mind that standard thin-set mortars can shrink and pull away from the tile, causing voids and air bubbles during the curing process, so make sure that the mortar resists shrinkage too.