Types of ceramic tile, sealing and more
Ceramic tiles are one of the oldest flooring materials in the world and among the most beautiful. Traditionally made from clays or mixtures of clay types, they can be found covering floors throughout most of the world, particularly in North Africa and much of the Middle East. Intricately patterned ceramic tile floors can be seen in houses in Italy and Spain. Tiles lined the interiors of some Egyptian tombs. Clay tiles laid on church floors in Mexico shortly after the first Conquistadors arrived are still beautiful despite centuries of constant wear.
For your house, what type of tile do you have in mind? You can choose from floor tile, counter tile, and wall tile; glazed, high gloss, or slip resistant; indoor and outdoor.
Types of Ceramic Tile
Ceramic tile comes in a wide variety of sizes and colors. Each piece may range from one inch to 24 inches across. It can be hexagonal, octagonal, round, square, or diamond shaped. Both handmade and mass produced tiles are rated for durability, hardness, and ability to resist water absorption.
The main types of tile are glazed or unglazed porcelain, mosaic, quarry, and pavers.
Glazed porcelain tile consists of two parts: the glazed surface and the body, which is known as the bisque. Most ceramic tile is given a glazed coating and then baked, much like pottery. Glazes can be high or medium gloss, matte finish, and even slip resistant. They are made in literally thousands of different colors and patterns. Glazed tiles are essentially waterproof unless cracked or chipped.
Ceramic porcelain floor and wall tiles are usually made from refined clays, mixed with the manufacturer's own secret formulas for strength, durability, and color. The smaller tiles, four inches and under, are usually mounted on netting and can thus be placed in groups rather than individually.
Mosaic tiles are those two inches or less across. They may be glazed or unglazed. In unglazed tiles, the color is consistent throughout, which means they are nearly impossible to wear out. Mosaic tile is usually porcelain, which is a particularly hard tile that also has the lowest water absorption rates. Small hexagonal porcelain tiles are still to be found in commercial bathrooms and hallways around the country because of their great durability.
Quarry tiles are square, unglazed tiles made from common clays or shale. They are baked at high temperatures to help increase strength and reduce porosity. Quarry tiles are commonly red in color and range in size from six inches on a side up to 12 inches and are about 1/2 inch thick.
Pavers are similar to quarry tile but normally are thicker, up to one inch, and are built for heavy wear areas. They are large in size, commonly 12 inches on a side and sometimes bigger. Like quarry tiles, they are made from common clays and fired at high temperatures.
Unglazed pavers are commonly used outdoors but serve well indoors, too. Widely known as saltillo or Mexican pavers, these tiles are mostly made by hand. Because of this, they are irregular and not all the same thickness or color, which adds to their rustic charm. Saltillo needs to be sealed once or twice a year so they don't absorb excess water. If you're lucky, you might find one with a cat or dog print on it.
Sealing the Tile
Glazed tiles are nearly impervious to water and in themselves do not need to be sealed. But grout is absorbent and needs to be sealed. Both tile and grout must be cleaned before they are sealed, particularly in bathrooms and countertops, where moisture helps promote mold.
If the grout is loose or cracked, break it out with a screwdriver tip or grout saw and repair it before sealing. Small cracks can be repaired by pressing some grout in with your fingertip. Water can soak through cracked grout, get under the tile, and possibly rot the substrate. If that happens, then all of the tile may have to be pulled up.
Unglazed tiles, such as saltillo and pavers, should be sealed to help keep them clean and stain free. New saltillo should be sealed before they are grouted to help prevent mortar from sticking to them. Sealing also prevents colored grout from bleeding into the tile. If a spot or two of thinset is wiped from part of a saltillo, manufacturers recommend wiping the whole tile so that the wipe mark will not show.
There are two primary types of tile sealants: penetrating and surface. Penetrating sealer soaks into the tile itself rather than remaining a surface film.
A surface sealer lays a thin coating on top of the paver and alters its appearance. One example is a gloss or semi-gloss sealer that gives the paver a wet appearance.