Mesh backing is applied to small mosaic tiles, typically 1 inch by 1 inch, to speed up installation. Mosaic tiles are generally made of three materials: ceramic, glass or porcelain. Of the three types, ceramic is the most common. It is also the most porous and will have the shortest lifespan in a shower. Glass and porcelain tiles are both non-porous and strong, offering the best performance in showers and other wet areas. The difference between glass and porcelain is cosmetic. Glass tiles are translucent, while porcelain tiles are glazed and opaque.
Tile installed in showers requires the use of a waterproof backing. This backing protects the frame from any water that might leak through the grout. It also protects the tile adhesive from moisture that might leach through the walls. Most tile manufacturers make recommendations as to which backing to use with their products. These include adhesive sheets, concrete backer board and even mortar-like products applied with a trowel. Other products, like backer boards with a water-resistant gypsum core, fiberglass backing and waterproof coating are often used in bathroom tiling projects.
Standard thin-set or mastic are appropriate for ceramic tile installation, but impervious materials like glass and porcelain require adhesives with better sticking power. Latex modified thin-set, or latex modified Portland cement mortar are recommended for glass and porcelain tile. Epoxy grout is recommended for porcelain and glass tile due to its impervious surface and greater flexibility. Standard cement grout is suitable for ceramic tile, although it should be sealed regularly to maintain water-resistance.
Use a three-sixteenth-inch V-notched trowel for spreading adhesive. Back-butter glass and porcelain tiles to ensure adhesion. To back-butter, use the smooth edge of your trowel and spread a thin layer of adhesive across the backs of your tiles. Gently push the mesh panel into the adhesive and wiggle it in place. Only apply the amount of adhesive to the wall that you can tile in 10 to 15 minutes. After this time, the adhesive will begin to dry and the adhesive bond won't hold. Apply grout 24 to 48 hours after installation.