A leaking toilet in an HDB flat is more than just an annoyance; it can lead to strained relationships with neighbours, costly damages, and worries about complex HDB regulations. Understanding HDB toilet waterproofing is crucial for every flat owner in Singapore to prevent problems and ensure a healthy living environment.
Whether you’re planning a renovation, dealing with a sudden leak, or simply want to be prepared, this guide covers everything you need to know. At Atlas Works, we specialise in waterproofing solutions tailored for HDB properties, offering effective and minimally disruptive options like our advanced non-hacking nano-technology.

Understanding HDB Regulations for Toilet Waterproofing & Renovation
Renovating your HDB toilet involves specific rules set by the Housing & Development Board (HDB) to maintain building integrity and prevent issues like inter-floor leaks. Key regulations include:
- Mandatory Waterproofing Replacement: If you hack or remove existing toilet floor tiles during renovation, you must replace the waterproofing membrane. This is crucial to prevent leaks to the unit below.
- HDB Registered Contractors: All renovation work, including waterproofing, must be carried out by a contractor registered under HDB’s Registered Renovation Contractors’ Scheme (RRCS). Using non-registered contractors can lead to penalties.
- Renovation Permits: You generally need an HDB permit for works involving the replacement of floor or wall finishes (tiling) and any hacking. Check the HDB website for the latest permit requirements before starting work.
- Waterproofing Standards: When replacing waterproofing, contractors must use HDB-approved materials like pre-packed waterproofing screed and ensure the membrane extends up the walls/kerbs by at least 150mm. A mandatory water retention test is conducted by HDB before new tiles can be laid.
- Restrictions:
- Hacking of structural elements is strictly controlled and requires prior HDB approval.
- Relocating plumbing pipes usually requires specific approval.
- The total thickness of floor finishes (screed and tiles) must not exceed 50mm.
Always refer to the official HDB website or consult your registered contractor for the most current guidelines before commencing any renovation.
Common Causes of Leaks in HDB Toilets
Understanding why leaks happen can help with prevention and diagnosis:
- Wear and Tear: Over time (typically 10-15 years or more), the original waterproofing membrane beneath the tiles can degrade and fail.
- Pipe Leaks: Water supply or drainage pipes embedded within the floor slab or walls can corrode or develop leaks.
- Sealant Failure: Sealants around floor traps, pipe penetrations, and toilet pan bases can deteriorate, allowing water to seep through gaps.
- Grout Degradation: Cracked or porous grout lines between tiles can allow water ingress over time, eventually overwhelming the underlying membrane.

Inter-Floor Leaks in HDB Flats: Who is Responsible?
This is a common point of concern for HDB residents. Here’s the general principle:
- Shared Responsibility: According to HDB guidelines, the upper and lower floor flat owners share the responsibility for maintaining the floor and ceiling slab between their units. This means both parties generally need to cooperate on investigations and share the costs of repairs required to fix leaks originating from the slab or waterproofing membrane.
- The Process:
- Communicate: Approach your neighbour promptly and courteously to discuss the issue.
- Investigate: Work together to identify the source of the leak. This often requires engaging a professional waterproofing contractor.
- Agree on Repairs: Based on the contractor’s assessment, agree on the necessary repair method (e.g., hacking, non-hacking solution) and the associated costs.
- Share Costs: Split the repair costs as mutually agreed upon.
- Role of HDB/Town Council:
- Common Property: If the leak originates from the roof (affecting top-floor units) or external walls, it’s considered common property, and the Town Council is responsible for repairs.
- Mediation: While primary responsibility lies with owners, HDB or the Town Council might sometimes assist in facilitating communication or mediation if disputes arise.
- Goodwill Repair Assistance (GRA): HDB offers this scheme under specific conditions (e.g., for leaks within a certain period), but it’s not guaranteed. Check HDB’s website for eligibility.
- An example of GRA letter from HDB : here

Steps to Take When You Suspect a Toilet Leak
Acting quickly can prevent further damage and costs:
- Investigate & Document: Try to pinpoint the source. Is it constant or intermittent? Take photos/videos of damp patches or dripping.
- Inform Your Neighbour: Speak to your upper or lower floor neighbour immediately to make them aware and arrange a time for inspection.
- Engage a Professional Contractor: Contact a reputable waterproofing specialist (like Atlas Works) together with your neighbour for an accurate diagnosis. HDB provides a list of suggested contractors, but you can choose your own.
- Get Quotes & Agree on Action: Discuss the contractor’s findings, recommended solution, and quotation with your neighbour. Agree on the repair method and cost-sharing.
- Proceed with Repairs: Schedule the work with the chosen contractor.
- If the leak appears to be from common property (e.g., external pipe), contact your Town Council.
Choosing the Right Waterproofing Solution for Your HDB Toilet
You have options when it comes to fixing or preventing HDB toilet leaks:
Traditional Hacking: The Conventional Method
- Process: Involves removing existing tiles, hacking away the old screed and membrane, applying new waterproofing layers, re-screeding, and re-tiling.
- Pros: Completely replaces the old system.
- Cons (especially for HDB): Requires HDB permits, extremely messy and noisy, takes significant time (days/weeks), high cost, major disruption (especially if the flat is occupied), risk of damaging concealed pipes.
Atlas Works’ Non-Hacking Nano Solution: The Smart Alternative for HDB Homes
- Process: We apply our proprietary liquid nano-technology solution directly onto the existing tiles and grout. It penetrates deeply, sealing pores and hairline cracks invisibly without altering the appearance.
- Pros for HDB Owners:
- No Hacking: Avoids the mess, noise, dust, and lengthy disruption of traditional methods.
- Preserves Tiles: Keeps your existing toilet tiles intact – ideal if they are still in good condition.
- Fast: Treatment is often completed within a day.
- Less Disruptive: Perfect for occupied HDB flats, minimising inconvenience.
- Cost-Effective: Generally more affordable than hacking and re-tiling.
- Effective: Creates a durable, hydrophobic barrier within the substrate.
- Transparent: Doesn’t change the look of your toilet floor.
Our Proven Non-Hacking Process for HDB Toilets
Atlas Works brings expertise and a meticulous approach to every HDB toilet waterproofing job:
- HDB-Specific Inspection: Our specialists conduct a thorough assessment, understanding common HDB layouts and potential problem areas.
- Surface Preparation: We meticulously clean and prepare the toilet floor and grout lines to ensure maximum penetration of our nano-solution.
- Precision Application: The nano-technology liquid is carefully applied, ensuring complete coverage and sealing of potential leak points.
- Quality Assurance: We perform checks to ensure the treatment is effective and provide a comprehensive warranty for your peace of mind.

Tips for Preventing Future Toilet Leaks in Your HDB Flat
- Regularly check sealant (silicone) around the toilet bowl base, sinks, and pipe penetrations; reapply if cracked or peeling.
- Ensure floor traps are clear of hair and debris to prevent water pooling.
- Avoid using highly acidic or harsh chemical cleaners that can damage grout and sealants over time.
- Address any minor leaks or dripping taps promptly before they worsen.
Why Choose Atlas Works for Your HDB Toilet Waterproofing?
Selecting the right contractor is vital. Atlas Works offers:
- HDB Expertise: We understand the unique challenges and regulations of HDB properties.
- Non-Hacking Specialisation: Our advanced nano-technology is a proven, convenient solution ideal for HDB flats.
- Experienced Team: Our technicians are trained and experienced waterproofing professionals.
- Transparency: We provide clear explanations and detailed quotations with no hidden costs.
- Warranty: We back our non-hacking waterproofing work with a solid warranty.
Atlas Works Pte Ltd | Waterproofing & Painting Services Singapore | Residential & Commercial 122 Google reviews Yuqian Gao2025-04-26Trustindex verifies that the original source of the review is Google. Very professional very good job, the service is amazing, Bernard is very patient and tried his best to explain to me everything. Recommended -Jumkaana -2025-04-24Trustindex verifies that the original source of the review is Google. There’s been a water leak affecting a lower-level unit, and I contacted several companies for assistance. Most just quoted a price and mentioned a 1-year warranty without properly investigating the issue. One even said that if it leaked again within two weeks, they’d remove the toilet bowl to inspect it—but only for an additional charge. What set Eric apart was his thorough approach. He took the time to carefully investigate the possible sources of the leak and answered all my questions in detail. That level of service is truly exceptional. Thank you, Eric! khaled mokri2025-04-23Trustindex verifies that the original source of the review is Google. Neighbour downstairs complained of leaking from pipes above. Hdb came and we failed the water test. Called Atlas and queries were answered promptly and honestly. Price was also agreed upfront. Worker came the next available day and completed the work efficiently. Quick and with no fuss at all. We then passed the water test!!! Highly recommend Atlas, quality workmanship at a good price. There’s also a warranty for a peace of mind. Gu Bo2025-04-21Trustindex verifies that the original source of the review is Google. Bernard was very thorough and helped us understand clearly the condition of the apartment using his moisture meter and expertise Andy Quek2025-04-21Trustindex verifies that the original source of the review is Google. After comparing few quotes, I finally engage on Atlas work for my whole house painting. Bernard is very professional and quick in replying. We chat like we know each other for long time. This is most impt in choosing contractor as the communication is impt. Before actual work, there was a Alot of changes here and there but he is patient and make sure he replies to all queries. As nothing is perfect in all company, same goes for Atlas. after painting there are parts not painted properly. Feedback to Bernard and he make sure all remedy work are done to perfection! End day, I am a happy customer. Look for Bernard, make sure he is busy and don't let him rest! 🤣 Peter Morrison2025-04-13Trustindex verifies that the original source of the review is Google. I engaged Atlas to quote for fixing some water leakage issues and was immediately impressed with their thoroughness and professionalism. The crew that attended worked hard on a variety of jobs for two long days and were quiet, respectful, and thoroughly competent on every job. I'd definitely recommend them. Hwee Koon Goh2025-04-10Trustindex verifies that the original source of the review is Google. Prompt responses, helpful recommendations and clear explanations right from the start upon enquiry about painting my home. The painters did a good job, making sure to fix cracks before painting, pointing out areas of concern and explaining the work process so I know what to expect. They are also pleasant, approachable and reassuring. 👍🏻 Angeline Chua2025-04-09Trustindex verifies that the original source of the review is Google. I engaged Atlasworks for waterproofing for my toilets and planter boxes as well as a pipe bypass back in January, and their team proved to be efficient, responsive, and meticulous. Three months later, my neighbor below experienced a ceiling leak and suspected my planter box to be the cause. The team went the extra mile to help perform water ponding test, which confirmed that the waterproofing was effective and my planter box was not responsible for the leak. Throughout the entire process, their team has been exceptionally supportive and proactive in assisting to resolve the dispute with my neighbor. Their dedication to quality workmanship and customer satisfaction is evident, and I would highly recommend their services. ST Lee2025-03-25Trustindex verifies that the original source of the review is Google. I would like to express my appreciation for the excellent water seepage repair work carried out today. Your team demonstrated professionalism, efficiency, and attention to detail. From the initial assessment to the completion of the repair, the team was thorough in identifying the root cause and ensuring a proper solution. The workmanship was meticulous, and the area was left clean and tidy after the job. It made the entire process smooth and hassle-free. Thank you once again for your outstanding service. I would not hesitate to recommend your company to others in need of similar work.
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Conclusion
Dealing with HDB toilet waterproofing doesn’t have to be a stressful ordeal. By understanding HDB rules, responsibilities, and the available solutions, you can effectively manage leaks and protect your home. Atlas Works provides a modern, efficient, and HDB-friendly non-hacking waterproofing solution that saves you time, money, and disruption.
Ready to solve your HDB toilet leak issues? Contact Atlas Works today for a free consultation and quote!
- Call/WhatsApp: [+65 8800 0567]
- Email: at***@********ks.sg
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