Concrete walls or formwork blocks are insufficient to ensure that no water penetrates or leaks. Identify weaknesses in the structure and install a compatible joint.
For a watertight pool, a waterproof coating can be applied to the floor (raft) and walls of the pool. The coating makes the pool watertight and resists water pressure.
Contrary to popular belief, tiles and mosaics, like swimming pool covers, have a mechanical function of protection and finishing, not waterproofing. Waterproof pool covers are therefore indispensable under decorative coverings, such as paint or tiles.