Updated 2026-10-10 · by Seepwise
Short answer: Published 2026 contractor guides put a toilet waterproofing package (membrane, screed and ponding test) at about S$800 to S$2,500 per toilet, plus about S$800 to S$1,500 for hacking and disposal. Spalling patches were quoted from about S$300 to S$1,200 in 2017. Landed roofs have no reliable published rate and are priced after inspection. GST and re-tiling may be extra.
Seepwise writes these guides from HDB, MND and BCA sources and published Singapore price data; each claim links to where it comes from.
Published ranges, by job
| Job | Published range | Source |
|---|---|---|
| Toilet waterproofing package (membrane, screed, ponding test) | S$800 to S$2,500 per toilet | 2026 contractor guides (Triton, PRDT, Hock Star) |
| Hacking and disposal | S$800 to S$1,500 per bathroom | Same 2026 guides |
| Hacking and disposal, by area | about S$3 to S$8 per sq ft | Smart Calculator, Jul 2026 |
| Screeding, by area | about S$1 to S$3 per sq ft | Smart Calculator, Jul 2026 |
| Full HDB toilet renovation | about S$5,000 to S$8,000 | MoneyBees, 2026 |
| Spalling concrete patch to whole toilet ceiling | about S$300 to S$1,200 | PropertyGuru, 2017 (older) |
| Landed roof waterproofing | No reliable published rate | Priced after inspection |
These are published market figures from contractors and calculators, not our prices. Your quote depends on the inspection.
What changes the price
- Hacking or not. Hacking and disposal can match the cost of the waterproofing itself.
- Area and shape. More floor and more wall upturn means more membrane.
- Substrate condition. Cracked or uneven slabs need repair before any membrane.
- Tiles. Re-tiling is often quoted separately.
- Access and floor. Lifts, debris removal and working hours in condos.
- GST. Ask whether 9% GST is in or out.
Cost by situation
- One leaking HDB toilet, old flat: a waterproofing package plus hacking, shared with your neighbour if the leak is into their ceiling, possibly with HDB’s Goodwill Repair Assistance co-paying half. See who pays.
- New BTO with a leak: report to HDB; the 5-year warranty may cover it.
- Spalling in the bathroom ceiling: a patch repair, or GRA at 50%.
- Landed flat roof: inspection first; the substrate decides.
Get a personalised range with the waterproofing cost estimator.
Bottom line
For a toilet, budget the published S$800 to S$2,500 package plus S$800 to S$1,500 for hacking, and check GST and tiles. For leaks and roofs, the price follows the inspection. Request an inspection for a quote on your actual job.
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More questions
Why do waterproofing quotes vary so much?
Scope. Some quotes include screed, hacking, tiles and GST; others do not. Compare line by line.
Is GST included in waterproofing quotes?
Not always. Guides flag 9% GST as a common hidden cost, so ask.
Can I get a price without an inspection?
For a toilet package, an indicative range. For a leak or a roof, the source and substrate decide the price, so expect a quote after inspection.