Internal: 2K cementitious with reinforced corners; detail penetrations. For new/external faces: pre‑applied HDPE. Use crystalline as supplementary negative‑side treatment. Perform 72‑hr fill test.
LQ-POOL
Summary
Swimming pool leakages demand watertightness under constant hydrostatic pressure and chemical exposure. Treat new or accessible externals from the positive side; for retrofits, deliver a robust internal (negative-side) system that is compatible with tiling.
Symptoms
- Water loss and dampness on outer walls
- Efflorescence behind tiles or along overflow channels
- Leaks at inlets, outlets, lights, and other penetrations
Probable causes
- Inadequate joint detailing and rigid coats over moving cracks
- Poor pipe penetration treatment and tile bed delamination
- Discontinuous terminations or unprotected laps on external membranes
Standard remedy overview
1) Positive side (new or accessible)
- Pre-applied HDPE bonded membranes at raft and walls with protected laps
- Proper terminations and mechanical protection
2) Internal negative-side system (retrofit or repair)
- 2K cementitious membrane (potable-safe) to target DFT with reinforcement at corners
- Detailed treatment at inlets/outlets, lights, sumps, and overflow channels
- Crystalline slurry as a supplementary densifier where specified
Recommended technologies
- 2K cementitious (potable-safe) for internal faces
- HDPE pre-applied bonded membranes for positive-side builds
- Crystalline slurry as supplementary negative-side treatment
Quick SOP
1) Cure concrete; grind/clean; form 20×20 mm fillets
2) Internal: 2K cementitious in two crosswise coats; reinforce corners and details
3) Positive side (if possible): pre-applied HDPE with protected laps and terminations
4) 72-hour fill test; rectify and re-test; proceed to tile with C2 adhesive and epoxy grout
Decision guide
- New pools or accessible externals → positive-side HDPE
- Retrofits with persistent damp behind tiles → internal 2K cementitious (potable-safe)
- Cracks requiring load transfer → epoxy injection with surface membrane overlay
Acceptance criteria
Video Masterclass
SpecX Masterclass: Swimming Pool Leakages — Coming soon
Disclaimer
Notes
Ensure chemical compatibility of internal coatings with pool chemistry; maintain flexible detailing at all penetrations.