Ceramic tile floors are an attractive and durable addition to high-traffic and wet areas in a home. But, like any floor, a ceramic tile floor can become soiled or stained if it isn't sealed properly and regularly. Different types of ceramic tiles and grout have distinct features that should be considered when choosing sealing products.
Unglazed Ceramic Tile
With unglazed ceramic tile floors (such as Mexican Saltillo, thin bricks, quarry tiles, encaustic tiles, ceramic mosaic and geometric tiles), it is important to consider that some sealants will add a finish that may not be the appearance that you wish to create. Sealers can create a shine whereas an unglazed tile has a matte-like or natural appearance. In addition, the type of grout used should also be considered. Some strongly colored grouts can leech color into porous tiles, creating stains along the grout lines. For this condition it is important to think about using a specific grout sealer. Sealers can also change the color of both tile and grout. When possible, test your product on an inconspicuous tile such as one in a corner or inside a closet.
Penetrating Surface Sealers
Some tile manufacturers recommend specific sealers for their products. With unglazed ceramic tiles, any quality penetrating surface sealer will work to seal both the tile and the grout. When both the tile and grout are being sealed at the same time, the sealer can be applied with a mop. The objective is for the floor and grout to be very clean at the time the sealer is applied, and then apply the sealer evenly so that there aren't any large puddles. However, some high-shine sealers leave a haze, so pre-test the sealant finish on your tile before doing an entire room.
Porcelain tiles are also ceramics but they are considered impervious to most staining, so the tile will generally not need an applied sealer finish. If a sealer is necessary then porcelain tiles should receive a breathable type of sealer. It is important not to allow any excess sealer to sit on porcelain tiles as this may become sticky if left on, producing an unpleasant new problem. However, the grout around porcelain tiles may not be as stain resistant and a penetrating grout sealer may be applied to just the grout. This can be a time-consuming process.
Glazed Ceramic Tiles
Glazed ceramic tiles come in many types, and with some glazings the tile may still be absorbent. This can be tested by taking a spare tile and pouring water on the glazed surface. If the tile changes color and absorbs the water, or some of the water, then you should consider treating the tile more like an unglazed tile, with a penetrating surface sealer. If the tile doesn't absorb water easily, then it is designed to be used without a sealer. You can still apply a breathable sealer if you are concerned about staining or ease of cleaning. You can also opt for the grout-only sealers.
Sealers are often determined by usage habits. If a porous floor is in a high-traffic area, with messy people and animals, then it can make sense to reduce staining. It is a good idea to consider other types of sealers or products designed for problems such as pet urine odors and mildew and mold prevention. It is also a good idea to steam clean your ceramic tile floors periodically to reduce grinding dirt into the surfaces. Inexpensive steam cleaners can keep most ceramic tile floors looking like new; simply dry the tiles after you clean them for the best appearance. You should reseal your floor when the sealer breaks down. You can test this by placing 2-3 tablespoons of water on a tile and grout section that is in a high traffic area of the floor and waiting for five minutes. If the water sinks in or if the tile/grout changes color from absorbing some water, then the surface sealer may no longer be working. Resealing should take place no more often than once a year.