Waterproofing Cost in Singapore: What You'll Actually Pay (2026)
Prices checked October 2026 against the published price lists of 526 contractors listed on Homees, MOM's 2025 wage data and Qanvast's 2026 report. How we price →
Waterproofing is the least glamorous line in any renovation and the one you absolutely cannot skimp on. In 2026, standalone re-waterproofing of a toilet runs **S$400–S$800**, a standard waterproofing package (membrane + flood test) is **S$800–S$1,200**, and a full job that includes hacking, membrane and re-tiling lands at **S$1,500–S$3,000+** per bathroom. Priced by area, the membrane itself is about **S$25–S$100 per sqm**.Here's the honest part: a quote that's 30% cheaper because it quietly drops the waterproofing membrane or the flood test will cost you five times more in two years, when the leak reaches your neighbour below and you're paying for structural repairs. This is the silent guardian of the whole flat. Spend properly here.
| Work | Typical cost | Notes |
|---|---|---|
| Standalone re-waterproofing | S$400 – S$800 per toilet | Targeted, ~2–3 sqm |
| Standard package (membrane + flood test) | S$800 – S$1,200 | Per bathroom |
| Full: hack + membrane + re-tile | S$1,500 – S$3,000+ | Per bathroom |
| Liquid / PU membrane | S$25 – S$100 per sqm | By system & coats |
| Balcony waterproofing | S$25 – S$40 per sqm | Outdoor |
| Roof (landed) | S$30 – S$60 per sqm | S$3,000–S$6,000 typical |
Indicative 2026 ranges. Final price depends on area, wall coverage, screed depth and whether hacking/re-tiling is included.
Two ways to do it
Full waterproofing is the proper job: hack off the tiles, apply a primer, lay the membrane, protect it with a cement screed, then re-tile. Most contractors now use a 3-step PU (polyurethane) membrane system. It's the most reliable and what you want for a real bathroom renovation or any resale flat.
Overlay / chemical injection skips the hacking — a non-invasive fix for minor leaks, around S$800–S$1,500 per unit. It's cheaper and faster, but it's a patch, not a rebuild. A trustworthy contractor diagnoses the root cause of a leak before proposing either; if someone quotes a method before finding the source, be wary.
Cost by area and method
| Job | Cost |
|---|---|
| Standalone re-waterproofing (toilet, ~2–3 sqm) | S$400 – S$800 |
| Standard package (membrane + flood test) | S$800 – S$1,200 |
| Full hack + membrane + re-tile | S$1,500 – S$3,000+ |
| Overlay / chemical injection (minor leaks) | S$800 – S$1,500 |
| Liquid / PU membrane | S$25 – S$100 per sqm |
| Cementitious screed over membrane | S$45 – S$75 per sqm |
| Balcony | S$25 – S$40 per sqm |
| Roof (landed terrace) | S$30 – S$60 per sqm |
For a typical HDB bathroom (4–6 sqm floor + 10–14 sqm of wet wall), the waterproofing portion alone runs roughly S$480–S$1,900 depending on how much wall is covered and the screed depth.
The flood test is mandatory — don't let anyone skip it
After the membrane goes down, the bathroom floor is flooded and left for 24–48 hours to prove there are no leaks before the tiles seal everything in. This water ponding test is non-negotiable — it's the only way to catch a failure while it's still cheap to fix. If your quote doesn't mention it, push back. A contractor confident in their work runs it as standard.
The HDB 3-year BTO rule
If you have a BTO flat, HDB prohibits removing the bathroom/toilet wall and floor tiles for 3 years from key collection — specifically to protect the original developer-installed waterproofing membrane. So new bathroom waterproofing only comes up after that 3-year window, or in a resale flat.
When you do waterproof, the work should follow BCA's Good Industry Practices for Internal Wet Areas and SS 637:2018. The technical details matter: the membrane must form a continuous angle fillet (about 25mm radius) at every wall-to-floor junction, be dressed cleanly around floor traps, and extend over pipe collars. These can't be patched on afterward — they're built into the sequence. Waterproofing, plumbing rerouting and hacking all need HDB approval, which your contractor or ID applies for.
Why you never cheap out here
A failed waterproofing job doesn't stay your problem. Water seeps to the unit below, rots structural beams, corrodes metal and triggers repair bills that easily exceed S$5,000 — plus a very unhappy neighbour. The membrane and the flood test are the cheapest insurance in your whole renovation. Get the warranty in writing too: 3–10 years is normal, with a 5-year PU warranty common. Check whether it's a manufacturer (product) warranty or an installation (contractor) warranty — you want clarity on both.
Sample budgets
Waterproof 2 bathrooms (standard package, membrane + flood test): roughly S$1,600–S$2,400.
Full bathroom renovation waterproofing (hack + membrane + re-tile, per bathroom): S$1,500–S$3,000+ — note this overlaps with your hacking and tiling budgets, so don't double-count.
Balcony (~8 sqm): about S$200–S$320 for the membrane, more if re-tiling.
The costs people forget
- Wall coverage & screed depth — these swing the per-bathroom price more than the floor area does.
- Detailing (angle fillets, floor-trap and pipe-collar dressing) — part of a proper job, not an extra to negotiate away.
- Permit & approval time for HDB.
- Re-tiling — if you hack to waterproof, you're also paying to tile again (see the tiling guide).
- Warranty type — product vs installation; get it in writing with start date and exclusions.
Rules worth knowing
- BTO 3-year rule: no removing bathroom tiles for 3 years from key collection.
- BCA Good Industry Practices + SS 637:2018 govern internal wet-area waterproofing.
- HDB approval required for waterproofing, plumbing rerouting and hacking.
- Flood test before tiling — standard practice, insist on it.
How to keep the bill sensible (without cutting corners)
- Never drop the membrane or flood test to save money — it's the worst possible saving.
- Diagnose the root cause of any leak before choosing a method — overlay may be enough for a minor issue.
- Compare itemised quotes (materials, labour, test), not lump sums — the cheap lump sum is hiding something.
- Get the warranty in writing and know whether it's product- or installation-backed.
- Coordinate with tiling and plumbing so you're not paying twice for hacking and make-good.
Comparing waterproofing contractors on Homees.co is the easiest way to line up itemised, warranty-backed quotes.
FAQ
How much does waterproofing cost in Singapore? Standalone re-waterproofing of a toilet is about S$400–S$800; a standard package with membrane and flood test is S$800–S$1,200; and a full job with hacking, membrane and re-tiling is S$1,500–S$3,000+ per bathroom. By area, the membrane is roughly S$25–S$100 per sqm.
What is the HDB 3-year waterproofing rule? HDB prohibits removing bathroom and toilet wall and floor tiles in a BTO flat for 3 years from key collection, to protect the original waterproofing membrane. New waterproofing typically only happens after this period or in a resale flat.
Is the flood test really necessary? Yes. After the membrane is applied, the floor is flooded for 24–48 hours to confirm there are no leaks before tiling. It's the only way to catch a failure cheaply. If a quote omits it, ask why.
What's the difference between full waterproofing and overlay? Full waterproofing hacks the tiles and applies a fresh membrane and screed before re-tiling — the reliable, lasting option. Overlay or chemical injection is a non-invasive patch (S$800–S$1,500) for minor leaks, cheaper but less durable.
How long does waterproofing last / what warranty should I get? Warranties run 3–10 years, with a 5-year PU system common. Get it in writing and check whether it's a manufacturer (product) warranty or an installation (contractor) warranty.
Why is waterproofing so important? A failed membrane lets water reach the unit below, rotting beams and corroding metal, with repair bills easily over S$5,000. It's the cheapest insurance in a renovation — never the place to cut costs.
Does waterproofing need HDB approval? Yes, along with any plumbing rerouting and hacking. Your contractor or interior designer applies for the permits, and the work should follow BCA Good Industry Practices and SS 637:2018.
Sources
- Renovation Contractor Singapore — Toilet waterproofing Singapore 2026: HDB 3-year rule
- Fortified — Plumbing cost Singapore 2026 (waterproofing per sqm)
- HERA Bathroom — The cost of retiling a bathroom in Singapore (2026)
- Waterproofing SG — Bathroom waterproofing cost: complete pricing guide
- The Vinyl Flooring — How much will waterproofing cost?
Prices are indicative market ranges as of 2026 and vary by area, method, wall coverage and warranty. Waterproofing in wet areas should follow BCA Good Industry Practices and SS 637:2018.
