Updated 2026-10-10 · by Seepwise
Short answer: If the bathroom floor is hacked, generally yes. Hacking floors in wet areas needs an HDB renovation permit, and your renovation contractor applies for it, not you. Non-hacking work such as PU injection does not hack the floor. In new flats, wet-area floor tiles should not be changed in the first three years, and changing them can end HDB's 5-year ceiling-leak warranty.
Seepwise writes these guides from HDB, MND and BCA sources and published Singapore price data; each claim links to where it comes from.
The short rule
Hacking bathroom floors generally needs an HDB renovation permit, and so does raising floor levels in kitchens, balconies and bathrooms, because incorrect works add structural stress (Hometrust). The permit is applied for by your renovation contractor. Unauthorised works can be ordered reinstated at your own cost.
New flats have extra rules
- In the first three years, wet-area floor tiles should not be changed, so the waterproofing membrane can settle (Hometrust).
- HDB’s ceiling-leak warranty for new flats runs 5 years and ceases if floor tiles are changed or the waterproofing system is tampered with (HDB).
If a new flat leaks, report it to HDB before any contractor touches the tiles. Doing the repair yourself can cost you the warranty that would have paid for it.
Which waterproofing jobs hack the floor
| Job | Hacks the floor? | Permit likely |
|---|---|---|
| Full toilet re-waterproofing (membrane renewed) | Yes | Yes |
| Re-screeding to stop a ceiling leak below | Yes | Yes |
| PU injection into cracks and joints | No | Not for the hacking |
| Overlaying new tiles | No | Not for the hacking, but it does not fix a failed membrane |
Confirm the exact permit requirement for your flat with your contractor before work starts; rules are set by HDB and can change.
What a permitted job should include
A membrane across the floor and turned up the walls, new screed to fall toward the floor trap, and a ponding test of at least 24 hours before tiling (guide). See what a ponding test is.
Bottom line
Hacking means a permit, applied for by the contractor. In a new flat, check the three-year rule and the 5-year warranty first. Request a quote and the specialist confirms the permit route for your flat.
Want this checked at your home?
A specialist calls you back to book an inspection.
Request received.
A specialist will contact you on the number you gave. If water is near electrics, switch off that circuit at the distribution board and keep clear until then.
More questions
Who applies for the HDB renovation permit?
Your renovation contractor applies for it, though you as the owner remain responsible for the works.
What happens if the work is done without a permit?
HDB can treat it as unauthorised and require the flat to be reinstated to its original condition at the owner's cost.
Can I overlay new tiles without a permit?
Overlaying is the common way to avoid hacking, but it does not repair a membrane that has already failed.