No-hack waterproofing, and the leaks it cannot reach

Last updated 31 October 2026.

Singapore search results are full of “non-hacking waterproofing”. The phrase covers at least four different jobs, and the advertisements rarely separate them. One is regrouting: the cement or epoxy in the joints is raked out and replaced, tiles untouched. One is silicone at the floor-wall joint, the bath rim and the trap. One is injection: a small port through the grout fills the void under a hollow tile. One is a liquid or a clear film rolled onto the glaze. Only the last of these is marketed as a membrane you can see. None of them is the sheet that was laid on the screed before the original tiles.

That distinction is the whole page. Water that is still inside the joint can be stopped at the joint. Water that has already passed the tile, crossed a tired membrane and wet the slab will keep crossing it after you paint the glaze. The way you tell them apart is a pond, not a brochure. Plug the floor trap. Keep the water below the doorway so it does not run into the dry area. Mark the level. Wait long enough to be honest, and look at the ceiling underneath. HDB’s guideline requires a water test after a tile replacement and does not publish the millimetres or the hours. Use the downstairs ceiling as the result. If it darkens, stop talking about coatings.

Inside the 3-year window the hack is not a choice you are allowed to make. HDB says the toilet floor and wall finishes must not be replaced for 3 years from the completion date of the block, because the membrane is there to protect the flat below. Adhesive overlay of new floor finishes is the exception they describe. Overlay raises the floor. You then have to live with the 50mm total-thickness limit, the door undercut, and a floor trap that must still take a long collar rather than a proud grating. A coating that leaves the original tiles in place does not trigger that replacement rule. It also does not repair the membrane those tiles are protecting.

Hollow tiles are the job people confuse with waterproofing. A dull tap on an intact tile means the adhesive has let go. Four to ten of those, injected through the grout, are S$350 to S$750, about three hours, and the screed stays. The hollow-tile guide is clear that injection is the wrong tool when the membrane has failed, the tile is cracked through, or the slab is moving. Filling the void then hides the leak. A single cracked tile with a spare is S$80 to S$180. A typical HDB bathroom regrout, when the field really is that size and the ceiling is dry, is S$400 to S$900. A mouldy silicone zone is S$80 to S$150. Those four sentences are the no-hack catalogue. A branded film over the shower wall is not among them. It is quote on inspection, and only after the pond says the ceiling is dry.

A new BTO adds a second clock. The defects liability period is 1 year from key collection. Report the stain before a private coating covers a defect the developer may still own. Hacking during that year, or during the 3-year finish ban, is how a defects claim dies and how an unauthorised-work problem starts. The permit guide already states fines up to S$5,000 for unauthorised work. V On Construction is the company on the HDB directory when a permit is actually required. Homey Furnishing does the rows above. We will not sell a one-day coating as a substitute for a membrane the pond has already condemned.

Good no-hack work is boring to look at. Joints raked back to a sound depth, not scratched. Dust vacuumed, not wiped into the next bay. Cement grout forced in and tooled, haze washed while it is still haze. Epoxy, if that is what was agreed, mixed to the ratio on the tin and the haze cut before it cures, because cured epoxy haze is the finish you will see for years. Movement joints in silicone, not in grout. A coating, if one is used at all, stopped at a line you can see, with the trap left able to drain and the weep paths of a window left alone. Sloppy no-hack work smears grout over mouldy silicone, bridges the floor trap, and calls a wet downstairs ceiling “settling”.

Homey Furnishing Pte. Ltd. (ACRA UEN 202018148K), 27 Mandai Estate, #06-10 Innovation Place, Singapore 729931, invoices permit-exempt leak checks, regrouting, silicone, and making-good after the water has stopped. V On Construction Pte. Ltd. (ACRA UEN 201611708H), on the HDB Directory of Renovation Contractors, invoices an HDB renovation permit when bathroom finishes are hacked or a new membrane is laid under new tiles. A concealed or new water-supply pipe is a PUB licensed plumber. Homey Furnishing is not that plumber and does not publish a waterproofing warranty term.

Curtains, blinds and roller shades are not part of this booking. Fabric window treatments are a different product, and these pages do not quote them.

Do the pond before you buy a product. A product that cannot be tested against the downstairs ceiling is a product you cannot judge.

1. Tap the field with a knuckle. Hollow and intact is injection. A ridge you can see is tenting, which is a lift-and-rebed, S$550 to S$1,200 for eight to twenty tiles, not a port.
2. Plug the trap and pond the wet area only. Photograph the mark and the downstairs ceiling at the start and at the end.
3. If the ceiling stays dry, decide grout versus silicone by looking at which joint is open. Grout is the grid. Silicone is the corner and the fitting.
4. If the ceiling wets, stop. Read the 3-year date. If replacement is forbidden, the conversation is HDB or the developer, not a private hack.
5. If replacement is allowed, the job leaves this page and becomes a permit membrane. Get the upturn and the water test in writing.

No-hack is most often an HDB question because of the 3-year rule. Condos and landed bathrooms fail the same way, and the person who can say no is different.

A liquid applied on tile can slow water that is attacking the grout. It is a wearing coat. It abrades where you stand, and it does not turn up inside a pipe chase you cannot see. Polyurethane injection into a crack is a crack fill. It is useful when you have found a crack and you are not pretending the whole floor is new. It is a poor match for a membrane that has failed in a wide patch under the shower. Hollow-tile injection re-bonds tile. It is not a waterproofing system, which is why the hollow-tile page sends membrane failures here, and this page sends them back once the pond fails.

If a contractor will not pond the floor because the coating “should not be flooded”, ask what test they will accept. A hose on the wall for a minute wets the glaze and proves nothing about the slab. A steam cleaner drives moisture into a joint and creates the stain you just paid to remove. The test is still water, a plug, a mark, and the ceiling below.

Use the downstairs ceiling as the switch. The bands are the ones already printed. A film over the glaze has no band.

Make the contractor say which of the four no-hack jobs they are selling.

1. Will any tile be lifted? If yes, who holds the HDB renovation permit?
2. What did the ponding test show on the ceiling below, and where is the photo?
3. Is the price the published regrout, the published injection, or a coating with no row?
4. If it is epoxy grout, who cuts the haze, and what happens if the haze cures?
5. Does the quote include the movement joints in silicone, or only the grid?
6. What do you do if the ceiling wets halfway through the pond?

If the lower ceiling is already dripping onto a light, stop the test and isolate the circuit. A ponding test is for a stain you can watch, not for a live fitting. The ceiling-repair page paints only after the leak has stopped, at S$150 to S$400 for a hairline or a water stain.

Inside the defects year, use HDB’s rectification route. Past that, and past the 3-year finish ban, a dispute with the upstairs owner about a slab leak is the inspection guide, not a coating bought in a panic. External-wall patches that appear in rain, with the bathroom unused, go to the town council. Window drips at the frame go to the window sealant page. Do not let a no-hack crew seal a window weep hole while they are in the toilet.

How you're charged

A leak or waterproofing job that already has a sentence on HomeySG uses that sentence. Nothing in this table is a fuel surcharge, and the handyman hour is not added on top of a band unless the written scope says so. A membrane, a balcony, a planter, a roof, an epoxy-grout system, or a listening survey with no matching row is quote on inspection.

Who is allowed to do the work

HDB’s renovation pages split a coat of silicone from a hacked bathroom. Replacing toilet wall and floor finishes is not allowed for 3 years from the completion date of the block, because a membrane sits on the screed. After that, a replacement uses pre-packed waterproofing screed, a membrane upturned at least 150mm at walls, kerbs and pipes, a UPVC floor-trap grating with a long collar, and a water test. Fines for unauthorised work are already written on the permit guide as up to S$5,000. Homey Furnishing does not sign the permit invoice.

• Regrout, a silicone zone, hollow-tile injection and a stain repaint after the water has stopped stay on the published rows. They do not replace a membrane.
• Opening the bathroom floor or wall finishes is V On Construction when the flat is HDB and the work needs a permit.
• PUB’s leak leaflet says it is an offence under the Public Utilities Act to engage an unlicensed worker for plumbing work. A concealed or new supply pipe is a licensed plumber. An exposed trap is a different visit.
• External walls of an HDB block are common property. The town council on the S&CC bill is the first report, not a private injector.
• SCDF does not allow hacking of household-shelter walls, floor slabs or ceiling slabs to chase a pipe. The leak is found another way.
• A window-frame leak is the window sealant page. Exterior rivets and stays stay with a BCA approved window contractor.
• Curtains, blinds and roller shades are not quoted here.

Ways to keep the bill smaller

• Photograph the stain, the wet room, and the water meter before anyone hacks. A hack that destroys the evidence is a second problem.
• Run one test at a time. Shower, flush, aircon and rain on the same afternoon make a useless log.
• If the joint is only mouldy silicone, the published zone is S$80 to S$150. That is not a membrane.
• If the ceiling is already dry and the source is fixed, the hairline repaint is S$150 to S$400. Paint on a live leak is how the stain returns.
• Buy the published regrout or the published injection when the photo matches. A coating quote that will not name a band is allowed to be quote on inspection. It is not allowed to borrow the S$400 regrout sentence.

WhatsApp the photos to +65 8561 0630.

No-hack prices that exist on this site are joint and tile repairs. The membrane hack is listed so you can see it is a different visit.

Anything not in that table is quote on inspection.

WhatsApp the photos to +65 8561 0630. The reply uses a band already printed on HomeySG, or it says quote on inspection.

Official pages, not a legal opinion

The 3-year rule and the water-test duty are on HDB’s renovation pages. We are not interpreting your flat’s permit for you.

• HDB, important renovation information. The 3-year restriction on replacing toilet wall and floor finishes, and the water test after a replacement.
• HDB building-works guidelines. Pre-packed screed, the 150mm membrane upturn, the 400mm stack detail on an open balcony, and the 50mm thickness limit.
• HDB ceiling-leak home-care guide. Flat owners maintain the interior. Leaks from common property go to the town council.

• When the membrane itself has failed
• Hollow-tile injection
• Epoxy or cement grout
• When a permit starts
• Handyman price list