Who Says Concrete Is Just For Slabs? -- Octagon, a concrete tile from Coronado Stone Products, convincingly emulates the look of ceramic and natural stone products. Photo courtesy of the Concrete Tile Manufacturers Association.

In 1975, U.S. tile consumption was made up primarily of quarry tile, 4 1/4-inch glazed wall tile, or unglazed mosaic. The overall consumption figure for 1975 was approximately 320 million square feet. By 1980, that figure increased approximately 37 percent. The rapid increase in consumption was due partly to the introduction of double-fired tile, which resulted in the introduction of more aesthetically pleasing tile that could also be used for flooring.

But this was not the only factor that accounted for the growth in consumption. Development of dry-set mortars made the cost of ceramic installations much less expensive -- not only from a material standpoint but also because the mortars allowed for faster installation. No longer were depressed slabs needed to allow for thick-bed installations.

At that point in time, the modes of tile distribution were also changing. The hundreds of foreign manufacturers then entering the U.S. marketplace needed warehousing and distribution channels. The direct method of manufacturer to tile contractor could not work in these cases. In my opinion, these three developments accelerated the tremendous growth of ceramic tile.

The process of setting ceramic tiles, though fundamentally the same as in years past, has evolved due to the increasing sizes of tile and growing popularity of hard, very low-absorbency porcelain tiles. For example, to meet the ANSI A108 required coverage (transfer) of setting materials, manufacturers have developed medium-bed mortars that not only improve transfer but, in some cases, fill slab voids and thus preventing cracking.

Because large-format tile cannot be effectively beat in using the old troweling patterns, a new method of troweling has also been developed to increase coverage. For porcelain tile, a dry-set mortar cannot be used. Instead, a latex-modified thinset is required to avoid hollow spots and disbonding. The latex provides an adhesive capability that is necessary when porcelain is used.

The larger-sized tile has also presented another problem -- specifically, an increased chance of cracking. The need for protection led to the development and use of crack-isolation membranes. Currently, ASTM balloting is underway to help bring stability and uniformity among available membrane choices. This initiative is long overdue, particularly because many installers are using products that may or may not be suitable, depending on slab conditions.

Though it’s installed essentially in a similar fashion to ceramic, marble tile has unique characteristics which need to be addressed. For example, certain black and green varieties of marble tend to curl from exposure to the water in a thinset mix. For these suspect tiles, an epoxy setting material is called for. As a matter of course, I recommend a white thinset for all others because marble is very porous and you’ll want to avoid potential discoloration -- especially in white, translucent stone. Another point to remember is to use small grout joints and only use unsanded grout to avoid scratching the marble tile.

In recent years, concrete tiles have enjoyed dramatically increased popularity. For example, concrete tiles now are being used in Disney theme park projects worldwide. Concrete tiles are available in myriad options of size, shape, texture, and color.

Concrete tiles are produced by three manufacturing processes -- poured, extruded or ram pressed. Manufacturers of concrete tile draw upon the very old art form of casting positive shapes from negative molds.

One point to remember is that concrete tiles should be sealed. Obviously, I’ve only scratched the surface of this topic. More comprehensive information on concrete tile may be obtained from the newly formed Concrete Tile Manufacturer’s Association. You can reach the association on the Internet at www.concretetile.org.