With modern tile design stipulating the use of large floor tiles on the walls of showers, bathroom walls and backsplashes, the line between floor and wall tile has become blurred. This may lead to confusion with some homeowners as to what designates a tile as "wall" or "floor" and when tiles can be used in various applications. While floor tiles are fine for wall use, wall tiles are not necessarily good for floors.
Wall Tile Manufacturing
Wall tiles, designated for use solely on the walls, are typically made from a material called slip. Slip is a mixture made from dried, crushed clay and mixed with water. The resulting material is a liquid clay that can be poured into moulds.
Wall tiles made of slip are thin and porous. They are dried and covered with a thin glaze before being fired to high temperatures.
Floor Tile Manufacturing
Ceramic floor tiles can be made of wet clay that is extruded or moulded on machines, or of compressed clay dust. The resulting tile is thicker and denser than ceramic tiles made of slip, giving them more durability. Ceramic floor tiles may be fired in a kiln once for light residential use, or twice for heavy, commercial use.
Wall Tile Glazes
Wall tiles can be glazed in one of three glaze types--the typical, glossy glaze, a crackled or crazed finish or a flat, matt finish. Glossy glazes are thin and brittle, as well as slick when wet. Using them on a floor may result in chips, cracks or breakage in the glaze, exposing the porous clay beneath.
Crackled glaze is fragile, since these cracks go straight through the glaze to the tile below. If used on the floor, they can collect dirt, stains or result in chips.
Matt glazed wall tiles may be used occasionally on floors in light traffic situations, but always check with the manufacturer before doing so.
Floor Tile Glazes
Ceramic floor tile glazes are typically matt or textured in finish to help prevent slips and falls. The glaze on a floor tile also is fired to a much higher temperature, resulting in a more durable glaze that is less likely to crack, chip or scratch in high-traffic areas.
Sizes of Ceramic Tiles
Ceramic wall tiles are most commonly made in a handful of sizes including four-inch, 4 1/4-inch, 3-by-6-inch, six-inch and eight-inch. Ceramic floor tiles are more commonly found in larger sizes, from six inches to 24 inches. This is because of the thickness of the floor tiles; they can support larger sizes without breaking the way a thin wall tile would.