How to Repair Cracks on an In-Ground Gunite Pool

An in-ground gunite pool is a concrete-based pool that also contains a layer of plaster that lines the inside of the pool walls and floor. Occasional shifts in the earth beneath the pool can cause stress fractures and cracks in the pool's surface. These cracks can be repaired immediately before the leaking water can present a long-term structural problem for the entire pool. To repair the cracks, however, your pool must be drained.

4-inch grinder saw
Waterproof silicone caulk
Plaster patch
Putty knife
Trowel

Instructions

- 1
  Drain the pool, using the filter's dedicated drainage system. Inspect the pool at this time for other hairline cracks in the structure that can be repaired while the pool is drained.
- 2
  Cut the crack with a grinder saw. Cut at least 1/2 half inch into the crack and extend the length of the crack by 1 inch on both sides. This will clean the crack and smooth out the surface prior to patching.
- 3
  Fill the crack about halfway with silicone caulk. Fill the rest of the crack with plaster patch, applying it with a putty knife. You must mix the plaster patch according to the product's instructions. Some plaster patches come already mixed.
- 4
  Even out the surface with a trowel. Make it as even as possible with the existing plaster. If the plaster will be exposed for several hours before the water reaches the height of the repair, cover it with a moist towel to prevent it from cracking.

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