When shopping around for tile it’s important to remember that not all floor tiles are created equal. In fact, every single tile manufactured and sold has an intended use, whether that is outdoor or indoor, decorative or commercial. To understand what tile you need, you will need to consider the space you intend to tile. Each box of tile is labeled with five or six ratings: grade, PEI, water absorption, coefficient of friction, frost, and tone. Understanding how to read these labels is the key to getting the most bang for your buck and essentially how to choose tile flooring for your home.
All tile comes with a grade from one to three. Grade one is the highest quality grade. Grade three is the lowest quality. Although grade two is very similar to grade one, it is almost always less expensive. Opt for grade two if it will save you money or even grade three if you only intend to use the tile for your walls. Grade three is not as durable as grades one and two, and should not be used for floor tiles.
The PEI rating is the wear rating. It stands for Porcelain and Enamel Institutes wear rating. Only glazed tile receive a PEI rating as they measure the glazed tile’s ability to resist abrasion. Ceramic tile rated PEI I and II should only be used as wall tile. They tend to be decorative and cannot withstand foot traffic. Tile rated PEI III offer moderate resistance to wear. Tile rated PEI IV are highly resistant to wear and tile rated PEI V are the most resistant. Tile that carries a PEI of III or IV are appropriate for use in residential areas—anything more than that is overkill.
A tile’s W.A. rating will tell you how much of the tile’s weight in water it absorbs and whether or not it is the right tile to use in a wet area such as a bathroom or outdoors. W.A. ratings have four categories. They are expressed as a name and the percentage of water absorbed by a tile. Nonvitreous tile absorbs more than 7% of its weight in water. Because of this nonvitreous tile is inappropriate for outdoor use or in other wet areas. Semiviteous tile absorbs between 3% and 7% of its weight in water. It too is only appropriate for use in dry, indoor areas. Vitreous tile absorbs 0.5% to 3% of its weight in water. Vitreous tile is appropriate for use outdoors and or in a moisture heavy room. Impervious tile absorbs the least amount of water–less than 0.5% of its weight. It too can be used outdoors or in a room where moisture is present. Because of its low absorption rating, this category is also referred to as porcelain. However, this label also comes with a price premium. A virtreous ceramic floor tile will do the same job you need it to without the heavy price tag.
Coefficient of Friction
Abbreviated as C.O.F, Coefficient of friction is a fancy term for slip resistance and is very important if you are considering installing floor tile. The lower the C.O.F. number the less friction the floor will provide and the more slippery it will be. A C.O.F. greater than .50 is recommended for standard residential applications. Consider going even higher if you are tiling your bathroom. The higher the number, the less likely you’ll be to slip when getting out of the tub or shower.
Frost tells you whether the tile can or cannot withstand freeze and thaw cycles. If you’re using a tile indoors, this rating doesn’t matter.
Tone only applies when there is intentional variation from tile to tile to mimic the look of natural stone. If you’re looking for a tile with consistent color, toned tile is probably not the best fit for you.