Installers work hard to produce a finished tile installation that is both pleasing to the eye and functional. To accomplish this task, the installer must have the hand skills necessary to complete the work correctly the first time using the best quality materials available.
When stopping the tile installation adjacent to another floor finish such as carpet or hardwood, it is important to protect the edge of the tile, whether a full tile or a cut edge. To do this, many manufacturers produce various trim shapes (profiles) that not only protect the tile edge; they also create a smooth transition to the adjoining flooring product.
One of the more commonly used profiles is the “L” angle which is available in a variety of colors and finishes to complement almost any decorating theme. The horizontal leg is embedded under the tile in thin-bed mortar while the vertical face of the angle shields the tile edge from potential damage which can be caused by other flooring product installers, foot traffic or objects moving across the transition. These edge treatments allow for grout to be installed between the profile and the tile, yielding a neat and professional appearance.
The functionality and appearance of these edge treatments serve a great purpose, but they only do so if they are installed correctly. Unfortunately, many installers have not been properly trained in the right way to install these profiles. If there is not enough mortar on top of the profile to support the tile (as shown in the attached photo), they have a good possibility of cracking.
As was stated above, the profile is to be “embedded” in the thin-bed mortar. This means there must be mortar both below and above the strip. After keying the thinset into the wood or concrete surface, trowel the mortar in one direction. Place the strip into the mortar and press it into place.
At this point, additional mortar must be applied in one of two ways. Either apply additional mortar with the notched side of the trowel in the same direction as the previously spread mortar on top of the profile, or back butter the edge of the tile. The tile is then moved perpendicularly (back and forth) to the direction of the mortar, yielding full coverage.
Installing these profiles correctly will provide a long-lasting tile job, but taking shortcuts will most likely result in failure.