If you're planning a bathroom renovation in Bali, or you've just moved into a villa and tiles are already starting to come loose, this article explains exactly what's happening and what proper waterproofing should look like.
The most common failure pattern I see in Bali villas goes like this: tiles were installed without a proper waterproof membrane underneath. The shower runs, water gets past the grout joints (they're never perfectly sealed, especially as they age), soaks into the concrete, and starts breaking down the adhesive bond. After 12–24 months, tiles start sounding hollow when you tap them. Within another year, some are rocking or lifting.
This isn't a tile quality problem. It's a waterproofing problem.
Before any tile adhesive goes down in a wet area, a waterproof membrane is applied to the substrate. In Bali, the most common products are cement-based waterproofing slurries (like Sika or Aquaproof) applied in 2 coats, or sheet membranes. The membrane goes:
The membrane needs to cure fully (usually 24–48 hours) before tiling begins. Tiling over wet membrane is a common shortcut that defeats the purpose.
If you're buying or renting a Bali villa and want to check: tap the floor and wall tiles. A solid sound means good adhesive contact. A hollow sound means the adhesive didn't penetrate or the tile has delaminated — either way it's a sign of future problems. Also check the grout around the shower base and in corners — if it's cracking or dark-stained, water is getting in.
For a new renovation: ask to see the membrane applied before tiling starts. If the tiler can't show you the membrane, assume it wasn't done. Our bathroom tiling service includes membrane as standard.
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