Summary
The majority of swimming pool leaks occur at the point the shell is penetrated by a light housing, water inlet or drain. Other reasons are as a result of poor construction (particularly around the construction joint) and inadequate waterproofing prior to tiling or plumbing issues. Unfortunately there are no quick and easy fixes. There are two general methods. The first is applying a cementious capillary active component which penetrates and crystallizes into a surface through the action of water. The second is to use a slurry or mortar which forms a watertight membrane.
1. Check pool leakage is not a result of a defective stop valve in swimming pool surge tank, excessive evaporation or insufficient overflow
2. Isolate adjacent electrical supplies (i.e. lighting).
3. Cover all adjacent areas walkways securely
4. Remove tiles (retaining some if in-pool structures i.e. stairs to be re-built)
5. Remove topping to concrete substructure incl. pool structures i.e. stairs
6. Check around light fittings / inlets / drains break out surround if required.
7. Cut 5cm inspection channel at construction joint around pool circumference
8. Plug light housings / inlets and drain surrounds with a recommended chemical mortar. Starter bar penetrations to be sealed with waterproof epoxy.
9. Apply crystal growth compound or slurry to pool shell. Allow 24-48 hours.
10. Refill pool and bucket test to access any leakage vs. normal evaporation
11. Rebuild pool structures, tile layout and re-tile.
12. Install relevant stonework / Sandwash etc