Consumers look to you as an expert on tile; be sure to give them the straight facts.

A technician tests the breaking strength of various tiles.
Initially, I considered entitling this article, "Ceramic Tile for Geniuses and Dummies," as a play on the titles of that popular series of how-to books. However, I reconsidered when I realized that no one would admit to being a ceramic tile dummy and, therefore, I'd be discouraging readers from delving into what truly is an important topic.

We hear it all the time: "My father (or uncle or cousin) has been in the business for 50 years and he always did it this way. He taught it to me, so it must be right." Or: "I know what I'm doing and don't need any more information."

Have you ever gone into a floor covering store, a tile outlet or a big-box store and met the super salesperson? You know, the one who says, "Sure you can tile over oriented strand board (OSB). I do it all the time. And sure, throw down a sheet of Luan underlayment -- that'll level your floor and work real well. Caulk, what is that? I never caulk any joints, because they don't look good and aren't needed anyway." In truth, these assertions are all fallacies of the uneducated.

Perhaps you've encountered that "interior designer" who says something to the effect of, "I don't care about specifications or industry recommendations, I just want the look" or "I don't want any control joints, they spoil the look."

But are such statements true and reasonable? Do they sound like they're coming from a genius -- or a dummy? And what about you? Are you a dummy or a tile genius? Probably, if you are human and working in this business, you fall somewhere in between those extremes. You have some knowledge but could use more. I've been in the tile business for 33 years and every day at work something new comes to my attention. You can never learn enough.

Unfortunately, when consumers hear these misguided pronouncements, they accept them as facts because they were uttered by "the experts." And that doesn't even take into account the advice of self-styled tile gurus on the Internet, or folks who write handyman columns or magazine writers who intermingle fact and fiction. Sadly, this type of bad information is promulgated all too frequently in our world.

Ceramic tile itself can be a complex subject. Take, just for an example, the tall tale about the color of the clay and how it affects tile performance. Relatively speaking, there is no such effect on performance -- quality is important, not the color of the clay.

Color, which is just one of the components in ceramic tile, indicates nothing. If your manufacturing plant is located near a good red clay deposit, that may make your finished tile red. If your plant is near a gray clay deposit, that may make it gray. If you're selling red-bodied tile in preference to gray bodied, of course you'll say red is better. You'd most likely take the opposite position if it's gray-bodied tile that you're selling.

In one of my presentations, I work with four different colors of clay tile. One measurement of tile performance is breaking strength. The American industry recommendation is 250 pounds per square inch (PSI). These four different-colored tile bodies have breaking strengths of 253, 256, 261 and 263 PSI. Is it magic that they all happen to be very close to the industry recommendation? I think not. In fact, that is why ceramic tile is an engineered clay product. The color of the clay does not indicate the performance of the tile.

Facts are facts. If a salesman says one color is better than the other, then report him to the tile police for a discriminatory violation!

Let's slice down the layers of complexity and make it simple. There are two major types of tile. The first is quarry tile, which is made by extrusion -- also termed the "wet" process -- from natural clay or shale. The second is tile that is made by the pressed-dust or "dry" method.

You may be wondering how a pressed-dust body can produce a strong tile. After all, dust isn't very strong, is it? In fact, this process is one in which the mineral components of the tile body are milled to very small particles (like dust) and then pressed under very high pressure to form the tile body. If all the particles are the same size and very small, they will compact into a strong body that, when heated in a kiln, will fuse into a strong, dense and low water-absorbing body.

The Tile Council of America utilizes this machine to conduct Modus of Rupture (MOR) tests according to International Standards Organization (ISO) recommendations.
The dust-press product category includes wall tile, mosaic tiles and floor tile. Both dust-pressed and quarry tile can be glazed or unglazed. Glaze is a ceramic surfacing material that is used to give the finished product a particular appearance.

A glaze is applied to many popular porcelain tiles, as well. And, since I broached the subject, just what are porcelain tiles anyway? They are tiles with water absorption of less than 0.5 percent. Any ceramic tile may be glazed or unglazed. When a porcelain tile is glazed, it is the glaze rating that indicates the durability of the wear surface. The fact that it is "porcelain" does not necessarily indicate the wear surface is indestructible.

Glazing today is a very sophisticated matter. Modern, high-volume plants incorporate a plethora of devices -- such as silk-screeners, waterfalls, sprays, dry-glaze dispersers, printing rollers and texturizing machines -- on a conveyor glaze line. Some factories have 15 or more applications of glaze material on one line before the tile is fired.

Why? To make the tile look natural and random. It is far more difficult to replicate the look of nature than to make a regular flat-colored glazed tile. Glazes are a thin finish that can and will eventually wear off of the tile. Selection of the area of use for different glaze ratings is important. Currently the world tile industry is using the following glaze wear rating system:

  • 0-Decorative tile only (look but don't scrub).
  • 1-Non-traffic area tile (put it on the wall).
  • 2-Light traffic (like bathroom traffic subject to slippers and bare feet).
  • 3-Residential inner rooms (kitchens, sunrooms, etc.).
  • 4-Light commercial (office buildings, showrooms, entryways).
  • 5-High traffic (shopping malls, fast food outlets, etc.).

Based on the telephone calls I receive at the CTEF and written information being published, I'd have to say that porcelain is probably one of the most misunderstood tile products. As I previously mentioned, this tile that has water absorption of less than 0.5 percent, which makes porcelain tile very strong and dense.

Because porcelain is so dense, it can be left unglazed and used on the floor. If this is the case, the tile will have no glaze to wear out and therefore will stay the same color and maintain the same look for a very long time -- maybe thousands of years.

Because porcelain tiles are the same color throughout their entire body (through-body tile), they can be polished and ground to size just like stone. However, I must emphasize that when a porcelain tile is glazed, it is the glazed surface that takes the wear, not the body. There are glazed porcelains on the market that only make a glazed wear rating of 2. There are also porcelains on the market that are not frost proof or even frost resistant. Granted, they are not the norm, but they are out there for sale today at a source near you!

I hope this article stimulates your thought process about ceramic tile. Product education is the key to happy customers and profitable sales and installations. I do not know of a single manufacturer in the tile industry that would not be happy to sit down with your group and help you along with all the little nuances of their product. If you want a broader and non-proprietary view, you're always welcome to contact me at the Ceramic Tile Education Foundation.