Glazed floor tiles -- such as Aretica by Esquire, a Florim USA brand -- are single fired at extremely high temperatures, and are the hardest, most durable and arguably the most beautiful tile variety.

Increasingly, we are being asked to do PKs -- an acronym for “product knowledge” -- as an aid not only for distributor salespeople, but for contractors and architects as well. This is a good sign backed by good intentions. After all, the joke about industry experts is that they know more and more about less and less.

PKs go a long way in educating the distributors, contractors and architects who are always anxious for knowledge. They educate the “educators” who, in turn, are forced to extend and inform themselves rather than look foolish when doing a PK of their own.

PKs on ceramic tile are not usually done. Most people just believe that ceramic tile is ceramic tile is ceramic tile. Most end users are unaware of the differences between, for instance, a glazed wall and a glazed floor tile.

Glazed wall tiles do not have the breaking strength of glazed floor tile. Glazed wall tiles are predominantly available in 4 1/4-inch square format, although 6-by-6-inch sizes are becoming popular. Unfortunately, sometimes an end user will ask for a wall tile to be used on a shower floor. This is tantamount to asking for a slip/fall incident to happen. Glazed floor tiles are single fired at extremely high temperatures, and are the hardest, most durable and arguably the most beautiful tile variety.

Porcelain tile, being the tile type most impervious to moisture, is extremely hard and strong and can be used almost anywhere. As with mosaic tile, which also is impervious, porcelain tile bonding can be difficult due to the product’s virtually non-absorbent and dense characteristics. To achieve an acceptable bond, one must certainly use a thinset mortar with a latex additive, rather than a water-based alternative. The latex enhances the mortar’s “gluing” ability.

I noted that porcelain tile is impervious. I also should mention that, when installing tile as exterior cladding, you must consider absorption. This is particularly true in cold-weather climates, because water can enter the tile and, if subjected to freezing conditions, cause it to pop off the surface and fail.

I have seen this occur even in Las Vegas, which seldom experiences such weather conditions. In one particular instance, there was an unusual overnight drop in temperature just after a new wall tile installation had been completed. The following morning, all that remained of the installation was a pile of tile on the ground. Another Vegas example involved a hotel’s gigantic ceramic-lined swimming pool that popped overnight.

To put this condition in perspective, compare the water-absorption qualities of the following tiles. These are documented in American National Standards Institute (ANSI) A137.1.

Glazed wall tile -- water absorption may be non-vitreous at 7.0 percent but shall not exceed 20.0 percent average water absorption. (Glazed wall tile can hold a lot of water.)

Semi-vitreous tile -- water absorption of more than 3.0 percent but not more than 7.0 percent.

Vitreous tile -- water absorption of more than 0.5 percent but not more than 3.0 percent.

Impervious tile -- water absorption of 0.5 percent or less. As expected, the higher the tile’s rate of water absorption, the less dense it is.

Quarry tile -- may be either glazed or unglazed and is made by extruding natural clay. Ordinarily used in commercial areas, quarry tile is becoming popular in residential applications. The color of the clay used is the determining factor in the color of the finished tile. The most common format is 6 inches square.

Paver tile -- made by the dust-pressed method, and can be of glazed or unglazed porcelain or natural clay. Typically, these are 6 inches square or larger.

Porcelain tile -- either mosaic or paver, this tile variety generally is made by the dust-pressed method. Mosaics by themselves are generally 1/4- to 3/8-inch thick, and have a facial area of less than 6 square inches. To achieve a good bond with mosaics, you must allow a generous amount of your mortar to squeeze up and surround the tile’s sides.

Slip-resistant tile -- has greater slip-resistant characteristics than other tile types due to an abrasive admixture in the surface. A tile manufacturer will give the purchaser tiles with whatever slip-resistant quality the purchaser desires. Unfortunately, if you attempt to make a tile completely slip resistant, you ultimately restrict mobility and increase the odds of tripping.