As a countertop covering, ceramic tile offers many advantages over other materials such as wood, mica, or other laminates. Ceramic tile offers greater resistance to heat, scratching, discoloration, etc. than most other materials, while at the same time affording a look that adds to the overall beauty of the room. Another major advantage of ceramic tile is that it can easily be applied over existing surfaces, including mica, when redecorating. When installing ceramic tile on countertops, certain preparations are necessary. The reason for this is the uniqueness of the joining of backsplash and countertop surface, in what appears to be one integral joint forming a right angle. However, a proper countertop calls for the backsplash to be mechanically isolated from the countertop. The reason for this is to prevent cracking where the two join, which can result from counter movement or settling of the building.

This mechanical isolation is accomplished through a combination of techniques. Referring to illustration #1, it can be seen that the mortar bed on the countertop, whether thick or thin, is not continuous to the back wall, or under the cove joining the backsplash. This isolation allows the counter and wall to move independently of each other in the event settling or movement does occur. The thin space is created simply by cutting a line in the backer board before the tile is laid.

The second mechanical isolation technique, which is used in conjunction with the space in the mortar bed, calls for the use of metal lath on both the horizontal and the vertical surfaces. The purpose of the lath is to isolate the mortar on which the tile is embedded from the substrate surface, to prevent the transmission of any movement (settling, etc.) from the substrate to the tile itself. As can be seen in illustration #2, any cracking of the mortar in contact with the substrate surface will not be transmitted through the lath to the mortar behind the tile.

One more step that should be taken to assure that the countertop and backsplash installations will last indefinitely, is the use of some type of waterproof backing between the mortar bed and the substrate surface.When the installation is in mortar, a sheet of waterproof Kraft paper should be bonded to the substrate surface before the lath is applied. One exception to this is when a remodeling job is being done over mica or other finished counter surface. In the case of mica, the surface should be rough sanded and the tile applied with adhesive such as Super-Tek Dual Purpose. Dual Purpose may also be used for applying tiles to the backsplash.

As with any installation, careful thought to tile placement before actually setting tiles will result in an attractive, as well as long-lasting, countertop.

Illustration 17.1: Backer Board method Click Here for Details

Illustration 17.2: Lath in 3/4" to 1" of Mortar Bed Click Here for Details