Horizontal cracking of you pool tile is typical of underlying bond beam damage.
Your pool tile can often be the bellwether for the overall structural health of your pool. Cracked or popping tile can be a sign of damage to your swimming poolís bond beam, a structural component of your pool wall that sits on top giving it horizontal strength. If the bond beam shifts or breaks it can cause your pool tiles, which lay directly over the beam, to pop off or crack. Not all tile damage is a sign of structural damage to your pool though!
Pool tile differs from bathroom tile in that it is formulated to have a high free/frost resistance, high thermal shock resistance, very low water absorption, and high chemical resistance. It is possible to use the kind of tile you find in a DYI superstore but not recommended. If you must, try to find a floor grade tile Ė at least grade 3, higher is better. Avoid tile sheets where lots of tiles are place on a fiber grid. Tile mats do not ensure enough bonding area to the side of your pool. You will find that most modern pool tiles are glass although there are many pools where you will find legacy porcelain tiles. Replacing these tiles is often difficult because they are no longer made.
Before working on your pool tile, lower the water level in your pool to below your tile line.
Tile is falling off?
If a tile falls off it could be as a result of bond failure of the adhesive that was used to set the tile. It could also be a sign of a cracked bond beam. Look behind the tile for a horizontal crack. If you donít see a crack check your expansion joint between the pool deck and coping. If the caulking is bad or missing water could have run down behind your tile, froze, and popped it off the beam.
If the tile has fallen off leaving old thinset on either the tile or the wall itís a simple fix to put it back on. Remove the old grout and mud from the tile and its spot on the beam being careful not to damage either.
For a standard 6Ē x 6Ē tile put about 2 tablespoons worth of thinset on the back of the tile and spread it around a little, use more or less if you tile is larger or smaller. Press the tile firmly back into place and wiggle it around to ensure the thinset spreads evenly across the back of the tile. Be sure to keep space around the tile for grout. Take your grout and rub it into the empty joints around the tile. Itís easiest to just use your hands for this as you are not covering an entire wall. Once done, use a damp sponge to remove the excess grout. If a small chunk of the wall has pulled off with the tile, you should parge this back up with hydraulic cement before resetting the tile.
Tile is cracked?
A cracked tile may be caused by a cracked bond beam, freezing surface water pressing against the tile as it expands, or the tile may have been poor quality. I you canít find a match to replace the tile it is possible to repair it, but it wonít necessarily look good as new. The tricky part in repairing cracked tile that is still on the wall is removing it without further damaging it. You should cut out the grout surrounding the damaged tile using a grinder with a diamond cutting blade, a rotary tool, or an oscillating tool. Itís possible that after removing the grout the tile could just fall off. If you arenít so lucky try using a hammer and chisel or levering it out with a screwdriver.
Once you have gotten the broken tile off the wall you can repair it with either a thinset mortar or silicone tile adhesive. Once the adhesive has set follow the directions for replacing tile above.
Tile is chipped?
It is possible to repair a chipped tile surface even if you donít have the missing piece. Thoroughly clean the chipped tile and dry it off, use a hair dryer on the chipped portion for at least 20 minutes after it looks dry. Get a high-gloss, oil based paint that matches the color of your tile. Paint the chipped area with an oil based sealant and allow it to dry for 2 hours. Paint a thin coat of the high gloss paint over the chipped area and allow it to dry for 24 hours. Apply another coat of paint and let that dry for 24 hours as well. Once dry mix up some clear drying, 2 part marine epoxy and fill the chipped spot with the epoxy to the level of the tile surface.
Check out our tile repair section for the materials you need!