Ceramic and porcelain tiles are popular throughout homes on countertops, floors and walls. Porcelain tiles look very much like ceramic, causing many people to wonder what the difference is. Although porcelain tiles are a type of ceramic tile, there are differences in durability, strength and cost.
Ceramic and porcelain tiles are man-made products: clay combined with ferrous sand and water, then fired in a kiln to harden. Most ceramic tiles have a glaze over the top of the clay body, but some are unglazed. Porcelain tiles can be glazed or unglazed. Porcelain is made with clay that is purer and more compact than regular ceramic clay, and it is fired at a much higher temperature. The result is a product that is denser, less absorbent and stronger.
Porcelain tiles cost a little more than ceramic tiles because they use more refined clay, and the firing and handling processes are more costly. Both products have a wide cost range, depending on the size, thickness and pattern of the tile. Porcelain tiles that are unglazed and homogenous (made of the same material throughout the entire tile) tend to be the most expensive.
Tiling is a common do-it-yourself project for the home. Ceramic tiles are easier to cut, because porcelain is harder and denser. Ceramic tiles also bond more readily with the backboard when put in place. This makes them simpler for the non-professional to install.
Tiles are stained and then fired. The firing process can affect the shade of the stain or glaze used, causing colour variation from one batch to another. For that reason, tiles are sold in dye lots. It is important to order enough tiles so that the same dye lot is used throughout.
Porcelain tiles are more resistant to humidity and changes in temperature than ceramic tiles, because they are denser. This makes them more useful in outdoor applications, where they are less likely to crack from freezing temperatures than ceramic.
Porcelain tiles are stronger than ceramic, making them more likely to be used as flooring. Unglazed porcelain tiles are most durable for flooring, because they have no glaze to wear away from constant traffic. Even if they chip, they are composed of the same material throughout, so damage is not very noticeable.
For help in choosing ceramic tiles, the PEI rating gives the amount of scratch resistance of the tile. According to Home Addition Plus, a PEI of 1 is best used on walls, PEI 2 is for bathrooms and kitchens, PEI 3 is for other residential applications including floors and PEI 4 and 5 are for commercial use.
Porcelain tiles are denser than ceramic and therefore less able to absorb materials that are likely to stain. Unglazed ceramic tiles are fairly porous and are likely to stain. Ceramic tiles with a heavy, quality glaze do not stain easily. Tiles are held in place by grout, which is a very porous material. Grout is more likely to discolour and stain than either type of tile.