Unlike showers and tub surrounds, most backsplashes are installed on regular drywall. In these applications special concerns should be addressed to limit potential water damage.
Laminate Backsplash Concerns
A laminate counter is very cost effective compared to granite slabs or fancy imported marble and tile. Laminate counters fall into two basic groups, the simple flat style and those that have a molded curve in the back so that the counter and the backsplash are a single piece. The latter are watertight from the factory and maintenance is pretty much eliminated.
Laminate counters that are not molded from a single piece usually have a separate piece of the same laminate material. This piece is about 4" tall and is the same thickness as the counter. It comes in a length the same as the main width of the counter. Additionally, there is a smaller length often called a sidesplash, that is used running front to back on the short edge of the counter. This is usually adhered to the wall with construction adhesive or adhesive caulk. To protect the particleboard core of the laminate, a bead of caulk should be used to seal the joint along the entire corner. Caulk that matches the color of the laminate or basic clear will look good and provide the protection you need. Because the core of laminate counters are vulnerable to moisture, routine inspection of the caulk line will keep it sound. The area directly behind the sink is the area that sees the most water, so check there regularly to be sure the caulk is solid.
Sealing Tile Backsplashes
Tile backsplashes are perhaps the most common type found in homes these days, as they can be used with laminate counters, tile counters and solid slab surfaces such as Corian and granite. The corner joint in these installations can be caulked or grouted. Grouted corners can give a uniform appearance that matches the field tiles, but unfortunately this joint is very prone to cracking and separating. When cracks occur in the corner joint, caulking and regrouting are both viable options.
Fixing a cracked grout line is not terribly difficult and can be repeated over and over as needed, but there is a better way, however, that I have been using for years with great success:
During the tile installation I place tile spacers below the bottom course of tile. 3/16” is the size I use most often. When grouting time comes, I mask off the gap between the counter and the wall tiles with some painter’s tape. If the counter is tile, I like to grout this before the wall tiles are installed. With the corners protected from stray grout, I grout the wall tiles. I then let the grout cure and be cleaned up as usual. After the wall grout is set (usually the next day) I pull the tape and clean out the corner channel. This corner then gets caulked.
Caulk is available in nearly every available grout color, both sanded and un-sanded. This “grout” colored caulk is normally stocked at most big box stores in many of the more common colors. (If not it can be special ordered. Obviously getting your order in before the projects starts is a good idea if you are planning to use more exotic colors.)
When the colored caulk is fully cured, this caulk line is almost impossible to distinguish from the grout, so the installation appears seamless. After the required cure has elapsed, the grout is sealed with a penetrating sealer. This helps with cleaning issues and protects the substrate behind the tile. Having a waterproof and flexible barrier in the corner provides years of protection.
When the time comes, a simple re-caulking brings this vulnerable location back up to tip-top shape.
Solid Slabs and Solid Backsplashes
Installing a continuous strip of granite, as a short backsplash, on a granite counter is very much like the laminate installs above but since granite is water proof already a simple bead of caulk can be used to adhere the bottom of the backsplash to the top of the counter. This is all that is generally needed to prevent water from wicking its way under the backsplash. As an added measure, some folks will caulk the corner again once the back is set.