Drain your pool below the tiles that need replacing and let the area dry. Use a submersible pump to drain out enough water to leave the damaged area exposed and dry. Once the area is clear, turn off the pump and let the calacata tile dry off completely. It’s best to do this in bright sunlight, which will dry the tile quickly.

If you’re only replacing a couple stone tiles along a top edge, you’ll only need to drain enough water to expose the area and keep it from being splashed. If you’re redoing your entire pool, drain all of the water and let it sit for a day or 2, until it’s fully dry. There are also special adhesives available for re-attaching single marble tiles underwater. However, your repair will be much more effective and durable if you drain your pool first.

Use a grout saw to remove the grout around any cracked mosaic tiles. This tool essentially looks like a screwdriver with a saw blade on the end of it. Push the blade end against the grout and saw it back and forth to cut through the grout. Keep cutting through until you remove all of the grout around the tiles that need to be replaced.

Use a hammer and chisel to remove any damaged tiles. Place the tip of the chisel in the joint of the cracked tile, then tap it with the head of the hammer to break the tile away from the mortar. Keep tapping until the whole pool tile design comes away, then repeat on any other damaged cement tiles. If your tiles are small, you can use a small flathead screwdriver instead of a chisel.

Inspect the beam behind the polished tile for any necessary repairs. Look for cracks, open seams, an uneven surface, or missing chunks in the beam. If the damage is greater than some damaged tiles, you’ll need to shore up the base with hydraulic cement or a plaster mix. This is essential for ensuring the longevity of your pool as well as creating a flat surface for the pool tile to stick to.

If the damage looks like it could be extensive, contact a professional full-service pool company to help diagnose and repair the problem.