HDB · Condo · Landed · Renovation contractors
Published ranges, dated and sourced. Then a quotation after a flood test.
Overlay against hacking by bathroom type, the price per square foot, injection, making good below, the minimum charge, and what a quotation has to spell out. Send three photos; we reply within one working day and arrange an inspection and flood test by an applicator from our network before the job is quoted.
First response within one working day · Repair scope follows site assessment
Reviewed: November 2026
Reply within one working day, Mon–Fri. Rayson quotes; an applicator from its network inspects and installs.
Toilet waterproofing in Singapore costs, per bathroom, about S$600 to S$1,400 for a no-hack overlay on an HDB common bathroom and S$2,000 to S$4,000 to hack, waterproof and re-tile it, rising to about S$1,500 to S$3,200 and S$4,000 to S$8,500 for a condominium master bathroom, according to one Singapore waterproofing contractor's 2026 price guide checked on 2 November 2026. Renovation platforms' guides put the basic works of one bathroom, hack, waterproof and tile, at about S$3,000 to S$9,000, with the membrane line itself at S$400 to S$1,500. PU injection for a slab crack is S$300 to S$1,200 per job, and most contractors apply a minimum charge of S$500 to S$800. These are market indications, not Rayson quotations: Rayson formulates and supplies SealForce WB20, the membrane under the tiles (8 to 12 kg for a typical HDB toilet), and an applicator in the Rayson network inspects, flood-tests and does the work; Rayson quotes condo and landed jobs with the workmanship warranty in its quotation, and in an HDB flat a contractor on HDB's Directory of Renovation Contractors quotes.
Each range is a published market indication with its date and source; none is a Rayson price. Rayson supplies the membrane for method two; the applicator in the Rayson network tells you after a flood test which method your bathroom honestly needs.
A contractor seals over the existing tiles with its own materials, in two to four days. The 2026 guide: S$600 to S$1,400 for an HDB common bathroom, S$1,500 to S$3,200 for a condo master bathroom. Honest only where the membrane beneath is sound and water is weeping through grout; where a flood test already fails, it buys months.
When it is honestTiles and tile bed out, two coats of membrane rolled across the screed, into the trap and up the walls, a 24-hour flood test, then tiles. The 2026 guide: S$2,000 to S$4,000 for an HDB common bathroom, S$4,000 to S$8,500 for a condo master bathroom; renovation platforms put the basic works at about S$3,000 to S$9,000. This is the SealForce WB20 route.
The job step by stepPolyurethane grout injected into a crack in the slab from below, S$300 to S$1,200 per job (one contractor's guide, June 2026). It seals a crack; it does not rebuild a membrane. Right where the water path is clearly a crack.
Trace the source firstPatching a spalled ceiling below is a separate S$300 to S$1,200 (a home magazine, November 2024), from a patch the size of a phone to the whole toilet ceiling. In an HDB flat the slab repair itself is shared under the Goodwill Repair Assistance scheme.
Who paysFrom one Singapore waterproofing contractor's 2026 price guide, checked on 2 November 2026. Published by that contractor for its own work; other quotations will differ, and the floor areas are that guide's typical sizes.
| Bathroom | Typical size | No-hack overlay | Hack, waterproof, re-tile |
|---|---|---|---|
| HDB common bathroom | 25–35 sq ft | S$600 – 1,400 | S$2,000 – 4,000 |
| HDB master bathroom | 35–50 sq ft | S$900 – 1,800 | S$2,800 – 5,000 |
| Condo common bathroom | 30–50 sq ft | S$900 – 2,000 | S$2,800 – 5,500 |
| Condo master bathroom | 50–90 sq ft | S$1,500 – 3,200 | S$4,000 – 8,500 |
| Landed, guest to master | widest spread | S$1,200 – 2,600 (guest) | S$6,000 – 14,000 (master) |
| Line in a quotation | Published range, S$ | Source and date |
|---|---|---|
| Overlay only, per sq ft | 15 – 35 | One contractor's 2026 guide, checked 2 Nov 2026: surface preparation, primer, two-coat membrane, ponding test |
| Hacking and waterproofing, no re-tile, per sq ft | 45 – 80 | Same guide |
| Full hacking, waterproofing and re-tile, per sq ft | 80 – 150 | Same guide, with standard tiles |
| Minimum charge, per job | 500 – 800 | Same guide: most contractors, small bathrooms |
| Membrane line within a renovation | 400 – 1,500 | OneCompare, July 2026, checked 29 Sep 2026 |
| Hacking and disposal | 400 – 1,500 | OneCompare, July 2026 |
| Wall and floor tiling | 1,500 – 6,500 | OneCompare, July 2026, budget to premium tile |
| Basic works: hack, waterproof, tile | 3,000 – 9,000 | Qanvast, April 2024, and OneCompare, July 2026 |
| PU injection grouting, per job | 300 – 1,200 | One waterproofing contractor's guide, June 2026 |
| Making good a spalled ceiling below | 300 – 1,200 | Home & Decor, November 2024 |
Market indications, not Rayson quotations. The guides differ in what they include, GST, preparation and access among them, and no quotation is honest until the bathroom has been seen and flood-tested. The one line Rayson can state from its own data sheet: SealForce WB20 at two coats takes about 8 to 12 kg for a typical HDB toilet, under one 20 kg pail; the pail price is available on request.
Product name, number of coats or film thickness (SealForce WB20: two coats at 0.4 mm wet film).
To 1.8 m on a shower wall, at least 300 mm elsewhere; the detailing at the floor trap and at every pipe.
Held for 24 hours after the final coat; how the result is recorded and who witnesses it.
Hacking and disposal, screed, tile supply and laying, grout: each listed, or marked as excluded.
Days on site; in an HDB flat, noisy work on weekdays between 9 am and 5 pm only.
The workmanship warranty in years, and the material warranty (SealForce WB20: three years against defects).
The membrane is a small part of the bill. Access, hacking, detailing, tiling and the rules of the building set the rest.
Hacking and re-tiling need an HDB renovation permit through a registered renovation contractor, and noisy work runs on weekdays from 9 am to 5 pm only, which sets the programme and part of the price. In a flat under three years from key collection the bathroom tiles cannot be hacked without voiding the waterproofing warranty, so an overlay or a wait is the honest answer. Where the slab between two flats leaks from wear and tear, HDB's Goodwill Repair Assistance scheme co-pays half and the owners share the rest.
BCA's Strata Management Guide 13 presumes a wet ceiling comes from the unit immediately above unless evidence shows otherwise, which is why the bathroom above is usually the one rebuilt. Working hours, lift protection and debris disposal are set by the management corporation and appear as lines in the quotation; master bathrooms of 50 to 90 sq ft take the upper half of every range.
A guest bathroom overlay at S$1,200 to S$2,600 and a master bathroom hacked and re-tiled at S$6,000 to S$14,000 in the 2026 guide: size, stone or large-format tiles, and an upper-floor bathroom over a living room set the price more than the membrane does. The landed-home guide on this site covers the roof, the car porch and the planters that often leak at the same time.
SealForce WB20 is a one-part, water-based membrane applied in two coats at 0.4 mm wet film, about 0.56 kg/m² per coat: a 20 kg pail covers about 18 m² at two coats, and a typical HDB toilet takes 8 to 12 kg. Formulated and specified in Singapore, tested and released batch by batch here, with a three-year material warranty and an open technical data sheet.
Tell us the number of bathrooms and the dates. We reply within one working day.
Three photos: the floor and the trap, the walls around the shower, and any stain on the ceiling below. Tell us the property type and whether the bathroom is being renovated. We reply within one working day and arrange an inspection and flood test by an applicator from our network before the job is quoted.
One Singapore waterproofing contractor's 2026 price guide, checked on 2 November 2026: a common bathroom of about 25 to 35 sq ft runs S$600 to S$1,400 for a no-hack overlay and S$2,000 to S$4,000 to hack, waterproof and re-tile; a master bathroom of about 35 to 50 sq ft runs S$900 to S$1,800 and S$2,800 to S$5,000. Renovation platforms' guides put the basic works of one bathroom, hack, waterproof and tile, at about S$3,000 to S$9,000. Market indications; the quotation follows the inspection.
The same 2026 guide: a condominium common bathroom runs S$900 to S$2,000 for an overlay and S$2,800 to S$5,500 to hack and re-tile; a master bathroom of about 50 to 90 sq ft runs S$1,500 to S$3,200 and S$4,000 to S$8,500. Landed homes have the widest spread: S$1,200 to S$2,600 for a guest bathroom overlay and S$6,000 to S$14,000 for a master bathroom hacked and re-tiled.
The floor decides, not the price. A membrane is applied to the screed beneath the tiles; SealForce WB20 does not go over tiles. A no-hack treatment is honest only for a narrow set of faults, such as water weeping through grout over a membrane that is still sound. If the bathroom has failed a water test, water is already under the tiles, and surface sealers buy months, not years. An assessment with a flood test tells you which case you have before anyone quotes for hacking.
Contractors in the market offer no-hack overlays, with their own materials, at S$600 to S$3,200 per bathroom by type in the 2026 guide. Rayson's route is a rebuilt membrane under the tiles. An applicator in the Rayson network tells you after a flood test which route is honest for your bathroom; accept neither before the inspection.
The same 2026 guide lists scopes: overlay only (surface preparation, primer, a two-coat membrane and a ponding test) at S$15 to S$35 per sq ft; hacking and waterproofing without re-tiling at S$45 to S$80; full hacking, waterproofing and re-tiling with standard tiles at S$80 to S$150. A small bathroom is priced on the minimum charge, not on its area.
Most contractors apply a minimum charge in the region of S$500 to S$800 for a small job, covering the visit, the ponding test and disposal. A 3 m² HDB toilet is usually priced at that minimum rather than at a per-square-foot rate.
The membrane product and the number of coats or the film thickness; the height of the turn-up (to 1.8 m on a shower wall, at least 300 mm elsewhere); the detailing at the floor trap and every pipe; how long the flood test is held and how it is recorded; whether hacking and disposal, screed and tiling are included; the programme and the noisy-work hours; the length of the workmanship warranty and of the material warranty. Without each line, two quotations cannot be compared.
Downtime in the 2026 guide: two to four days for an overlay, seven to fourteen days for hacking and re-tiling. In an HDB flat hacking and tile cutting run on weekdays between 9 am and 5 pm only; each membrane coat dries before the next, the flood test is held for 24 hours after the final coat, and only then come screed, tiles and grout.
Two. Rayson warrants SealForce WB20 against material defects for three years, and the workmanship warranty is set out in the quotation: Rayson's in a condo or landed home, the listed contractor's in an HDB flat. The market spans the 2026 guide describes: two to five years on overlays, five to ten years on hacked and re-tiled work. Ask for both warranties in writing before you order.
HDB: the slab between two flats is shared; HDB's Goodwill Repair Assistance scheme co-pays 50% of a slab leak caused by wear and tear, the two owners share the rest, and HDB arranges the contractor once both agree. Condominium: BCA's Strata Management Guide 13 of November 2023 presumes the water comes from the unit immediately above unless evidence shows otherwise. Making good a spalled ceiling below is a separate S$300 to S$1,200 (a home magazine, November 2024).
SealForce WB20 is applied in two coats at 0.4 mm wet film, about 0.56 kg/m² per coat; a typical HDB toilet, a 3 m² floor with 300 mm turn-ups and a shower wall to 1.8 m, takes about 8 to 12 kg for two coats, under one 20 kg pail. The pail price is available from Rayson on request; on a S$3,000 to S$9,000 job the membrane is a small fraction, and what you pay for is hacking, detailing, the flood test and the tiling.
Rayson formulates and specifies the membrane in Singapore, supplies it and publishes its technical data sheet. In a condo or landed home, Rayson quotes and contracts the job, and an applicator in the Rayson network inspects, flood-tests, hacks, applies the membrane, flood-tests again and re-tiles, under the workmanship warranty set out in Rayson's quotation. In an HDB flat, HDB's rules let only a contractor on its Directory of Renovation Contractors take on renovation work, so there a listed applicator quotes and contracts with you directly. Send photographs of the toilet and of any stain on the ceiling below; we reply within one working day and arrange the inspection.
Rayson assistant
Answers from Rayson's own product information
Guidance only — confirm specifications with the Rayson technical team.