Pool Waterproofing in Bali: How and Why

The Bucket Test: Leak or Evaporation?

Before assuming the worst, do this. Fill a bucket with pool water and stand it on the pool steps so it's partly submerged. Mark the water level inside the bucket and the pool level outside it. Leave the pump running normally for 24–48 hours, then compare. Evaporation affects both equally, so if the pool has dropped noticeably more than the bucket, you have a leak. In Bali, normal evaporation runs roughly 3–5mm per day; losses well beyond that point to the shell or the plumbing.

Why Bali Pools Are Demanding

Pools face more stresses at once than almost any other structure on a villa. The shell is under constant hydrostatic pressure from the water inside; it heats and cools with every tropical day; chlorine attacks the surface continuously; and the whole structure moves as the building's foundation settles into Bali's volcanic and clay soils. Near the coast, salt air adds another load. Under all that, a hairline crack at the floor-to-wall junction — the single most common failure point — can lose several centimetres a week while looking completely intact.

Shell Leak or Plumbing Leak?

This distinction decides everything, because the repairs are completely different. A shell leak is water escaping through the concrete or finish — cracks, failed membrane, bad penetrations at lights and fittings. A plumbing leak is water escaping from the inlet, outlet or filtration pipework buried around the pool. We separate them with two tests: dye testing at suspected points in the shell (the dye is drawn into an active crack), and pressure testing of the pipework. Only once we know which it is do we quote, because chasing the wrong one wastes money.

How We Re-Waterproof a Pool

For an active structural crack, polyurethane injection seals it at the point of entry — the resin expands on contact with water and fills the crack. For dormant cracks and tired surfaces, crystalline treatment seals the concrete capillaries from within. Where the existing system has failed across the whole pool, we drain it, clean the shell, treat every crack and penetration, and apply a new system matched to the existing finish, then reinstate tile or render over it. Infinity pools get extra attention at the overflow channel and the thin view-edge wall, where constant wetting, drying and movement make leaks most likely.

Catch It Early

The reason to act on a slow pool leak quickly isn't the water bill — it's everything around the pool. A leak that runs for months undermines decking, erodes garden beds, feeds damp into adjacent retaining walls, and can destabilise the ground the pool sits on. Caught early with a bucket test and a dye check, most pool leaks are a contained, affordable repair. Left alone, they become a structural job. For the full service see our pool waterproofing page, compare systems in the materials guide, and check guide rates on the pricing page.