Nano Waterproofing in Singapore: No Hacking, No Mess

Nano waterproofing is a clear, penetrating sealant applied over existing tiles and grout. It soaks into tiny pores and hairline gaps and cures into a water-repellent barrier, stopping minor seepage without hacking. It works best for seepage through grout and tile joints, not for a waterproofing membrane that has completely failed.

Last updated November 2026

How nano waterproofing works

Tiles look solid, but grout lines and the tiles' surface are full of tiny pores and hairline cracks. Over time, water passes through them, reaches the screed, and finds its way into the slab and the unit below.

A nano sealant is made of very fine particles in a liquid carrier. When applied, it penetrates deep into those pores instead of sitting on top like paint. As it cures, it forms a water-repellent (hydrophobic) layer inside the grout and tile surface, so water beads up instead of soaking in.

Most nano coatings are designed to be clear, so your bathroom looks the same afterwards.

The process, step by step

1. Inspect and confirm: make sure the leak is coming through tiles and grout, not a broken pipe or a failed floor trap joint
2. Deep clean: remove soap scum, mould and dirt so the sealant can penetrate
3. Dry the surface: the area must be dry for the coating to absorb properly
4. Repair weak spots: re-grout badly damaged joints and seal gaps around pipes and the floor trap where needed
5. Apply the nano sealant: usually in more than one coat, covering grout lines and tile surfaces
6. Cure: leave it untouched for the curing time stated for the product

When nano waterproofing is the right choice

• Seepage through grout and tile joints
• Small, recent leaks caught early
• Bathrooms or balconies you don't want to hack (new tiles, BTO restriction, budget, time)
• As preventive protection for older grout

When it's NOT the right choice

• The membrane has completely failed: water already moving freely through the slab needs re-waterproofing
• Broken or leaking pipes: a plumbing repair, not a coating
• Cracked floor slab or structural cracks: need proper repair or PU injection
• Hollow, loose or broken tiles: water gets in behind them; they need replacing first
• Leaks that have run for years: usually mean damage the coating can't reach

If your bathroom falls into one of these, we'll recommend full re-waterproofing or PU injection instead, rather than sell a coating that only buys a few months.

Nano vs other methods

Looking after a nano-treated bathroom

• Use mild cleaners; harsh acids and bleach can wear the coating faster
• Keep an eye on grout lines and the area around the floor trap
• Fix cracked or loose tiles quickly before water gets behind them
• If a damp patch reappears below, get it checked early

Nano waterproofing for HDB flats

Because nano waterproofing doesn't involve hacking floor or wall finishes, it doesn't need an HDB renovation permit, and it's one of the few options for BTO flats still within the 3-year restriction on removing bathroom finishes. If you're dealing with a leak into the unit below, see our guide to ceiling leaks, including who is responsible.