Direct answer
The layer under pool tile must hold water on the structural shell. Petroseal commonly specifies polyurea or a documented multi-coat liquid system with seamless application at sumps, returns, and coves before any ceramic finish. Thickness is verified by gauge per method statement—not assumed from coat count alone.
Tile suppliers and pool contractors in Lahore may omit this layer in quotes; consultants should require the primary system in the BOQ before tile work is awarded.
System options
| Shell condition | Primary direction | Notes |
|---|---|---|
| New cast concrete pool | Petroseal polyurea system | Fast cure; seamless; see TDS/brochure |
| Complex geometry / fittings | Polyurea or PU with reinforced details | Penetration collars mandatory |
| Liner-based pool | PVC liner system | PLC/PVC liner products where spec calls liner |
| Renovation with access | Strip to shell; re-waterproof then tile | Do not tile over unknown legacy layer |
Tile interface
Use tile adhesive and grout classes compatible with the waterproofing manufacturer’s published guidance. Softening or re-emulsification of the primary coat from wrong adhesive chemistry causes leaks that appear as tile failures. Petroseal technical sales can coordinate with tile applicators on compatible systems.
QA holds
- Substrate moisture and pull-off test where specified
- DFT readings on shell before tile
- Penetration inspection photos
- No foot traffic on uncured coating
- Sign-off before tile mobilisation