8 Best Waterproofing Contractors in Singapore (July 2026)

Before you compare contractors, it helps to know what they are actually selling, because waterproofing is not one product. There are three broad systems, and a good specialist picks the right one for the surface rather than defaulting to whatever they have in the van.

Cementitious waterproofing is a cement-based slurry that bonds to concrete and screed. It is rigid, cheap and the workhorse under bathroom and kitchen tiles, but because it does not flex much it can crack if the structure moves. Liquid PU, or polyurethane, membrane is a seamless coating that stays flexible, so it handles the movement and thermal expansion of exposed surfaces like balconies and flat roofs far better. PU-cement hybrids try to give you both, the bond and rigidity of cement with the flexibility of PU, and they are the go-to for tricky wet areas and planter boxes that see standing water.

Where it goes matters as much as what it is. A bathroom or toilet needs waterproofing laid under the screed and tiles, which is exactly why a real fix often means the membrane, not the grout you can see. A balcony is exposed to sun and rain, so it wants a flexible membrane. An RC flat roof takes the harshest beating and usually gets a torch-on or liquid PU system. And a planter box is a quiet killer, because soil holds water permanently against the structure and needs a tanking-grade treatment.

The single most important habit to look for is leak detection first. Before anyone hacks a single tile, the contractor should trace where the water is actually coming from, using moisture meters, thermal imaging or ponding tests, because the visible damp patch is often nowhere near the real breach. A firm that reaches for the hacking tools before it has diagnosed the source is guessing with your money.

General Waterproofing is the one I would point most people to first, because it leads with the thing that actually matters: diagnosis before demolition. Operating since 2007 with well over a thousand completed projects, it runs a free onsite inspection using calibrated moisture measurement equipment, then gives you a written diagnostic report with an itemised quote rather than a vague verbal estimate. For a stained ceiling where nobody is quite sure of the source, that methodical approach is worth a lot.

The scope is broad: roof and ceiling leakage repair, bathroom and wet-area waterproofing, balcony, external walls, pool tanking, spalling concrete repair and PU-based crack injection. It works with established material brands like Davco, Sika, Mapei, Fosroc and Bostik and specifies the system to suit the surface, which is exactly the flexibility you want. Every job comes with a written workmanship warranty and a water ponding test to verify wet-area repairs before the crew leaves.

Website: general.com.sg
Location: Yishun Street 23, serving islandwide
Best known for: Diagnosis-first waterproofing with written moisture reports and warranties

Secure Waterproofing is the pick if you want a strong review record and a proper written warranty behind the work. It carries a 4.9-star rating across more than a thousand reviews, which for a building-repair trade is a genuinely deep track record, and it backs every job with a five-year workmanship warranty. That combination of volume and cover is the reassurance most homeowners are looking for.

The angle it pushes hardest is non-hacking waterproofing, meaning no noise and no mess, which suits occupied homes where tearing up a bathroom for days is not an option. Services span RC, metal and tile roofs, bathroom, kitchen, balcony and toilet treatment, swimming pool tanking, PU grouting, concealed pipe leak repair and rope access for high-rise external walls. It is a BCA-registered contractor and BizSafe 3 certified, and it has cleared over a thousand projects across HDB, condo and landed homes.

Website: securewaterproofing.com.sg
Location: Islandwide
Google Rating: 4.9 stars (1,000+ reviews)
Best known for: Non-hacking repairs with a five-year workmanship warranty

If your problem is specifically a leaking toilet or bathroom, Prima Seal is the specialist I would call. Its signature is flood infusion treatment, a chemical waterproofing method that seals the wet area from the surface without hacking or removing your existing tiles, and in many cases it resolves the leak within a day. For anyone dreading a week of dust and a re-tiling bill, that non-invasive route is the headline reason to shortlist it.

Beyond flood infusion it offers PU grouting and injection for cracks and voids, water pipe leak repair, and traditional hacking waterproofing when the membrane really has failed and there is no shortcut. It holds a 4.7-star rating, is a BCA-approved CR13 waterproofing contractor and is BizSafe Level 3 certified, so the credentials line up with the marketing. It is honest about when hacking is unavoidable, which I respect more than a firm that promises a magic surface fix for everything.

Website: primaseal.com
Location: Lower Delta Road, serving islandwide
Google Rating: 4.7 stars
Best known for: Non-hacking flood infusion for toilet and bathroom leaks

Proof-Tech is a strong all-rounder with more than twenty years in waterproofing, roofing repair and building maintenance. It leans into the heavier structural jobs, which is where experience really counts, and its bread and butter is PU grouting and torch-on membrane systems, the two workhorses for stopping water through cracked concrete and across exposed roofs.

The full menu covers ceiling, wall and window-frame leak repair, RC, metal and tile roof waterproofing, epoxy coating and grouting, concrete repair, and rope access work for facades and high-level leaks you cannot reach from inside. If your issue is not a simple bathroom seal but something structural, like a leaking roof slab or a cracked external wall on an older building, this is the kind of specialist depth I would want on the job.

Website: prooftech.com.sg
Location: Yishun Industrial Street, serving islandwide
Best known for: PU grouting and torch-on membrane for structural and roof leaks

SWC Construction earns its place for the leaks that have already beaten someone else. It positions itself around solving water problems other contractors could not, and the reason it can make that claim is detection: it uses thermal imaging through its LeakDetect approach rather than relying on a visual guess, which is how you find a breach that is nowhere near the visible stain.

With over twenty years of experience and both BCA and HDB approval, it covers PU injection grouting, clear penetrative treatment, roof, basement, balcony and swimming pool waterproofing, bathroom leak repair and rope access work. What stands out is the guarantee: it provides a warranty against any recurrence of the leak and offers a full refund if the problem is not resolved, which is about as much skin in the game as a waterproofing firm will put down. For a stubborn, recurring leak, that confidence is exactly what you want.

Website: swcconstruction.com.sg
Location: Woodlands Industrial Park, serving islandwide
Best known for: Thermal-imaging leak detection with a refund guarantee

M3M Services makes the list for one reason above all: it treats leak detection as a discipline, not a guess. Where most firms eyeball the damp patch, M3M offers a structured inspection with four approaches, non-destructive testing, destructive testing, special equipment scanning and direct inspection, so the diagnosis is based on evidence before any hacking is proposed. For an inter-floor ceiling leak where the source is genuinely unclear, that rigour saves you from paying to repair the wrong spot.

With around nine years in the trade, it handles ceiling and roof waterproofing, pond and wet-area treatment, plus painting, coating and minor construction to make good after a repair. It is a sensible call when the first question is not how to fix the leak but where it actually is, which is more often the hard part than people expect.

Website: m3m.com.sg
Location: Chulia Street, serving islandwide
Best known for: Non-destructive leak detection before any hacking

Eternity Waterproofing is a solid, well-credentialed choice with over fifteen years across residential, commercial and industrial jobs. It was named an SME 500 Singapore award winner in 2025, and it is BizSafe 3 certified, so it clears the safety and business-standing bars I want to see before letting a crew loose on a facade or a roof.

Its focus sits on the leak-and-repair jobs that older buildings throw up: roof waterproofing and leakage repair, wall and ceiling leaks, internal wall waterproofing and spalling concrete repair, which is the crumbling, rusting concrete you often find hand in hand with long-term water ingress. Like the better specialists it works with reputable material brands and matches the system to the surface rather than forcing one product onto every problem.

Website: eternity.com.sg
Location: Yishun Street 23, serving islandwide
Best known for: Roof, wall and spalling concrete repair on older buildings

Le Fong Building Services rounds out the list as a BCA-registered specialist that, like my top pick, leads with an investigation-first approach and the least-disruptive fix it can justify. It also carries thermal imaging and rope access in-house, so it can chase a leak up an external wall as readily as through a bathroom floor.

The range is genuinely comprehensive: nano and membrane waterproofing for bathrooms, balconies and pools, PU grouting, epoxy injection, cement grouting and underwater epoxy, roof restoration and repair, concrete repair and structural strengthening, plus leak detection. The detail I like most is the warranty, up to ten years on certain systems, which is a real signal of confidence in the workmanship. If you want one contractor who can both diagnose and carry out a wide spread of repairs, Le Fong is a strong finisher.

Website: lefong.sg
Location: Serangoon North Ave 4, serving islandwide
Best known for: Investigation-first repairs with warranties up to ten years

Prices swing with the size of the area, how bad the ingress is, which membrane system is specified, and whether the crew has to hack and reinstate tiles. Non-hacking treatments are cheaper and faster but are not right for every failure, while a full hack-and-retile costs more because you are rebuilding the wet area from the screed up. Always get the leak diagnosed and the scope written down before you accept a number, and treat these figures as a guide rather than a quote.

1. Detection before demolition. The contractor should trace the actual leak source with moisture meters, thermal imaging or ponding tests before hacking anything. Good waterproofing follows the standards and good-industry-practice guidance the Building and Construction Authority (BCA) sets for building envelopes and wet areas, and a serious firm can talk about that rather than just quoting a surface coat.
2. The right system for the surface. Cementitious under bathroom tiles, flexible PU membrane on balconies and exposed roofs, PU-cement hybrids for planters and heavy wet areas. A firm that recommends the same product for everything is selling convenience, not a fix.
3. A real warranty, in writing. Five to ten years on the workmanship, with a clear promise to return free if the leak recurs. The warranty length is the most honest signal of how confident a contractor is in the work.
4. BCA registration and safety certification. A BCA-registered waterproofing contractor and BizSafe certification tell you the firm meets recognised standards, which matters most on roof and rope-access jobs.
5. They understand the HDB inter-floor leak process. For a ceiling leak between HDB floors, the flat owners above and below share the cost of joint investigation and repair by default, and HDB offers a mediation route if the two households cannot agree. A contractor who has done these jobs knows how to document the source so the shared-cost conversation with your neighbour stays civil.

I am not a waterproofing company and nobody paid to be on this list. I built it the way I research any building-repair category: reading through Google reviews and local guides, checking each firm's live website for the methods it actually uses and how it diagnoses a leak, and weighing credentials like BCA registration and BizSafe certification against the marketing claims.

Ratings, prices and warranties shift over time, so treat the figures here as a starting point rather than a quote, and confirm the current details with the contractor before you commit. My aim was simple: give you a shortlist I would genuinely call myself, led by the firms that diagnose before they demolish.

Because the tiles and grout you can see are not the waterproof layer. In a properly built bathroom the actual membrane, whether cementitious or a liquid system, sits on the concrete slab and screed, underneath the tiles. Tiles and grout shed most water but they are porous over time, so water that gets through relies on the hidden membrane below to stop it reaching the structure and the ceiling of the unit beneath. That is why a genuine fix for a failed bathroom often means getting down to the membrane, and why simply regrouting the surface rarely stops a real leak for long.

By default the two households share it. Under HDB's inter-floor leak framework, the flat owner below and the flat owner above are each treated as responsible for helping resolve a ceiling leak, so the cost of the joint investigation and the resulting repair is typically split between them rather than pinned entirely on the upstairs unit. If the two sides cannot agree on the cause or the cost, HDB provides a mediation service to help them reach a settlement. You can read the current process on the HDB website, and it is worth engaging a contractor who can produce a clear written diagnosis, because that evidence is what keeps the shared-cost discussion factual.

A properly installed waterproofing system generally lasts anywhere from around five years for lighter surface treatments to fifteen or twenty years for a full membrane laid under tiles, depending on the system, the surface and the quality of the workmanship. Exposed areas like balconies and flat roofs age faster because of constant sun and rain, while a protected bathroom membrane can last much longer. This is exactly why the warranty length a contractor offers is such a useful signal, and why a diagnosis-led repair beats a quick surface patch that fails again in a year.

Often yes. Non-hacking methods like flood infusion and PU injection seal many toilet and bathroom leaks from the surface, without removing tiles, and can resolve the problem in about a day. They are cheaper, cleaner and ideal for an occupied home. The catch is that they are not right for every failure. If the underlying membrane has broken down badly or the screed is saturated, a proper fix means hacking, re-waterproofing and re-tiling. An honest contractor will tell you which situation you are in rather than promising a surface fix for a structural problem.

The good ones do, and it is the first thing I would ask about. Reputable specialists back their workmanship with a written warranty, commonly five years and up to ten years on certain systems, and the best will return to re-treat free of charge if the leak comes back within that period. Some firms go further with a refund guarantee if a recurring leak is not resolved. Get the warranty terms in writing, including what is covered and for how long, before you accept the quote.