Roof Waterproofing Singapore

Roof Waterproofing Singapore | Expert Solutions for Every Roof

Singapore's roofs take a beating from heavy afternoon downpours, direct sun, and near-constant humidity, often at the same time. When a membrane cracks or a roof was never sealed properly, water rarely shows up where it enters. Instead it turns up weeks later as a ceiling stain, a damp patch in a storeroom, or a puddle that won't drain after rain has stopped.

Aldisg (Aldi Construction Pte Ltd) is a Serangoon-based contractor handling roof waterproofing in Singapore for homes, offices, warehouses and factories. We're based at 444 Serangoon Road, and from there we cover Serangoon and the surrounding districts, including Farrer Park, Paya Lebar, Bugis, Rochor and Beach Road, for both preventive waterproofing and active roof leak repair.

What Roof Waterproofing Involves?

Roof waterproofing means sealing a roof surface concrete slab, membrane, or coated deck so water can't get through into the structure below. It's not the same as patching a visible crack. For roof waterproofing Singapore projects, proper work starts by tracing where water is actually entering, because on a flat RC (reinforced concrete) roof, water often travels sideways along rebar or through hairline cracks before it ever shows up indoors.

Depending on what a site inspection finds, the work can involve:

Surface preparation — clearing debris, removing failed coating, drying the substrate
Crack and joint treatment — sealing hairline cracks, expansion joints, and areas around pipe or drainage penetrations, which are common leak points
PU (polyurethane) injection grouting — for active leaks through concrete cracks or construction joints, injected so it expands and seals the pathway from within the slab rather than just covering it
Waterproof membrane or coating application — an elastomeric or cementitious system applied across the roof, chosen for the substrate and how much ponding or foot traffic the roof sees
Non-hacking waterproofing — where site conditions allow, treating the roof from the surface without breaking up existing screed or tiles, reducing dust and downtime for occupied buildings

A leaking RC flat roof on a warehouse, a ponding spot on an office rooftop, and a cracked parapet wall on a shophouse each need a different approach. The inspection decides which one fits, not a fixed package.

Key Takeaways

  • Site Inspection Before Quotation
    We inspect the roof first to identify the actual source of water entry.
  • Solutions for Different Roof Types
    From concrete and flat roofs to commercial and industrial roofing, the treatment is matched to the site condition.
  • Multiple Waterproofing Methods
    PU injection, membrane systems, protective coatings and non-hacking solutions are available where suitable.
  • Commercial & Industrial Experience
    Suitable for offices, warehouses, factories, shophouses and other commercial properties.
  • Safety & Professional Documentation
    Risk Assessments, Method Statements and trained height-access personnel are available for relevant projects.

What Causes Roof Leaks in Singapore?

Most roof leaks trace back to a small number of recurring causes:

Ageing or failed waterproofing membrane. UV exposure and years of weathering break down the protective layer, letting water through even without a visible hole.

Hairline cracks in concrete. RC roofs move slightly with temperature swings, and over years this opens fine cracks that widen during heavy rain.

Water ponding. Flat roofs with poor gradient or blocked outlets hold standing water instead of draining it away, and prolonged ponding wears down the membrane faster at that spot.

Pipe and service penetrations. Aircon pipes, drainage outlets and cable conduits passing through the slab are common weak points if the seal around them wasn't done properly.

Blocked or damaged drainage. Debris or damaged gutters/outlets increase water pressure on the roof surface and its joints.

Heavy, sudden rainfall. A roof with an existing minor defect can go from fine to actively leaking during one storm, simply because of the water volume involved.

If a leak only shows up during heavy rain and clears afterward, that usually means the defect is real but needs a certain volume of water to trigger it, not that the problem will resolve on its own.

Roof Waterproofing vs. Roof Leak Repair

Roof Leak Repair

Roof leak repair targets an active leak water is already coming through, and the priority is stopping it at the source, often with PU injection at the specific crack or joint.

Roof Waterproofing

Roof waterproofing is broader: treating the whole roof surface, or a defined section, to prevent leaks developing in the first place, or to renew protection once the existing membrane has aged.

Many jobs involve both stopping the active leak first, then assessing whether the surrounding area should be waterproofed to prevent the same problem showing up somewhere nearby. A leak that returns after a previous repair is usually a sign that only the symptom was treated last time, not the underlying cause.

If water is actively coming through a specific crack or joint, targeted repair may be the right first step. For urgent situations, emergency roof leak repair can help address active water entry before it causes further damage. If the existing waterproofing has deteriorated across a wider area or leaks keep returning, broader waterproofing may provide a better long-term solution.

Residential, Commercial and Industrial Roofs

Roofs behave differently depending on the building type and how they're used.

Residential roofs (HDB, condo, landed, shophouse). Common issues include ceiling stains in top-floor units, leaks around parapet walls, and ponding on utility roofs or flat sections above kitchens and bathrooms. For HDB and condo jobs, we can also support the paperwork MCSTs or town councils sometimes require before work begins.

Commercial roof waterproofing (offices, retail, business parks). Office and commercial roofs tend to have more penetrations aircon units, cable trays, signage mounts each a potential leak point. This approach is also important when planning roof waterproofing Singapore projects for occupied commercial buildings.

Industrial and warehouse roof waterproofing. Warehouse and factory roofs are usually larger, often metal deck or large RC spans, where an unnoticed leak can damage stored goods, machinery or racking below. These jobs often involve larger membrane or coating areas, and drainage falls and ponding zones are checked as part of the scope, since they're common failure points on large flat industrial roofs.

For facility managers, a leak that keeps returning after a previous "fix" usually means the original work addressed a visible symptom (a crack) rather than the underlying cause (a failed membrane section, a blocked drain, or a structural movement joint). We flag this during inspection rather than repeating the same patch.

How the Process Works

Step 01
Contact.

Call or WhatsApp with a description of the issue, or photos if you have them.

Step 02
Site inspection.

We check the roof surface, drainage outlets, joints, penetrations and any interior ceiling staining to trace the actual source of water entry.

Step 03
Diagnosis and recommendation.

We explain whether the job needs targeted leak repair, full waterproofing, or both, and why.

Step 04
Quotation.

Based on roof size, surface condition, access requirements and the waterproofing system needed.

Step 05
Preparation and treatment.

Surface cleaning, crack treatment, PU injection where needed, then the coating or membrane system.

Step 06
Handover.

We walk through what was done, the workmanship warranty terms, and any maintenance notes relevant to that roof.

For commercial and industrial sites that require it, we prepare Risk Assessments and Method Statements, and our rope access team holds Climber Certification and Fall Prevention training for rooftop and exterior work at height.

Other Waterproofing Services

Beyond roof waterproofing, Aldisg provides waterproofing solutions for other areas of residential, commercial and industrial properties. From wet areas and external walls to basements and balconies, we identify the source of water ingress and recommend the right treatment.

Waterproofing

Waterproofing

Protect your property from water seepage, leaks and moisture damage. Our waterproofing solutions are tailored to different areas and building conditions. From wet areas to external surfaces, we identify the source and apply the right treatment.

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Bathroom & Toilet Waterproofing

Bathroom & Toilet Waterproofing

Protect bathroom and toilet areas from water seepage and hidden moisture. We treat vulnerable floors, joints, corners and wet areas to help prevent leaks. Suitable for homes, commercial properties and building maintenance needs.

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External Wall Waterproofing

External Wall Waterproofing

Stop rainwater and moisture from penetrating through external walls. We identify cracks, damaged surfaces and common water entry points. Our waterproofing solutions help protect walls from damp patches and peeling paint.

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Basement Waterproofing

Basement Waterproofing

Protect basement areas from groundwater, seepage and water ingress. We inspect cracks, joints and other vulnerable points where moisture can enter. The right treatment helps keep basement spaces dry and protected over time.

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Balcony Waterproofing

Balcony Waterproofing

Prevent water from seeping through balcony floors, joints and surrounding areas. We address cracks, ponding and failed waterproofing that can lead to leakage. Suitable for residential and commercial balconies exposed to regular rainfall.

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Cost of Roof Waterproofing in Singapore

Roof waterproofing Singapore services from Aldisg start from S$500, with the final price depending on roof size, surface condition, access and the waterproofing system required.

For customers looking for affordable roof leak repair, smaller repair works may be more cost-effective when the problem is identified and treated early.

Roof Waterproofing Service Indicative Starting Price
Minor Roof Leak / Patch Repair From S$300
Roof Crack & Joint Sealing From S$350
PU Injection Grouting From S$400
Tiled Roof Waterproofing Treatment From S$500
Roof Waterproof Coating From S$500
Non-Hacking Roof Waterproofing From S$500
Concrete / RC Roof Waterproofing From S$800
Flat Roof Waterproofing From S$1,000
Roof Membrane Waterproofing From S$1,500
Residential Roof Waterproofing From S$1,500
Commercial Roof Waterproofing From S$2,500
Industrial & Warehouse Roof Waterproofing From S$3,500
Large-Scale Roof Waterproofing Site Assessment Required

These are indicative starting prices and not fixed quotations. The final cost depends on the roof area, existing surface condition, extent of leakage, access requirements, preparation work, and waterproofing system selected. A site inspection is recommended before confirming the final price.

Roof Waterproofing Timeline and Lifespan

A straightforward residential leak repair can often be completed within a day. A full roof waterproofing project especially on a larger commercial or industrial roof typically takes several days once surface preparation and curing time between coats are factored in. Rain can delay the work itself, since most coating and membrane systems need a dry surface and a dry curing window to bond properly.

On lifespan, professionally applied roof waterproofing generally holds up for around 5+ Years of Experience years, though this varies with the material used, application quality, and how exposed the roof is to sun, rain and foot traffic. Roofs are among the most exposed surfaces on a building, so they tend to need attention sooner than internal walls or floors.

Areas We Serve

We're based on Serangoon Road, and most of our roof waterproofing and leak repair work is within Serangoon and a short radius around it.

Serangoon. As our home base, Serangoon is where we handle the widest mix of work HDB and condo roof leaks, shophouse repairs, and commercial roof waterproofing along Serangoon Road and the surrounding estates. If you need an emergency roofer in Serangoon, this is where we can respond fastest.

Farrer Park. A short distance from our office, Farrer Park's mix of older shophouses, medical facilities, and newer developments each bring different roofing conditions, from roof leak repair on aging shophouse roofs to waterproofing for newer commercial units. This coverage extends naturally into neighbouring Little India, where similar shophouse and mixed-use roof conditions are common.

Paya Lebar. With a growing number of office towers and business parks, Paya Lebar sees a steady need for commercial roof waterproofing, particularly around rooftop mechanical areas and larger flat sections prone to ponding.

Bugis. Bugis combines heritage shophouses with commercial and retail buildings, so roof waterproofing here often has to account for older roof structures alongside modern renovations layered on top of them.

Rochor. Rochor's residential and commercial mix means we see everything from small-scale roof leak repair in older housing to commercial roof waterproofing for retail and office units, often on jobs where a previous patch hasn't held up.

Beach Road. Beach Road's commercial buildings and mixed-use developments call for waterproofing that can be scheduled around business hours, with commercial waterproofing typically planned alongside building management to limit disruption to tenants.

If your building is in one of these areas, or nearby, we're close enough to inspect the roof and start work without a long wait for scheduling.

When Should You Call a Professional?

Get a roof inspected if you notice:

  • Ceiling stains, damp patches, or musty odours on the top floor
  • Peeling paint or bubbling on ceilings/upper walls
  • Water ponding on a flat roof that doesn't drain after rain has stopped
  • A leak that returns in the same or a nearby spot after a previous repair
  • Visible cracks, lifted flashing, or a membrane that looks worn, chalky or blistered

These signs point to water intrusion, but only an inspection can tell you whether the fix is a targeted repair or a broader waterproofing job.

What to Do Before We Arrive

If you have an active leak:

  • Move furniture, equipment, or stock away from the affected area
  • Place a container to catch dripping water and reduce floor damage
  • Take photos or a short video of the leak, especially during rain, if safe to do so
  • Avoid climbing onto the roof yourself to inspect or patch it
  • Leave all roof and height access work to certified and trained personnel

Our certified roof waterproofing specialists will inspect the damage on-site and execute safe, long-lasting repair solutions promptly.

What Our Clients Say

Genuine feedback and verified experiences from residential, commercial, and property owners across Singapore.

G

Ghias Uddin

3 days ago

Aldi Construction works is very response and experience worker especially Renovation services and External painprinted by Rope access , Thnaks to Aldi Teams

K

Khairunnisyah Bte Buang

7 days ago

The workmanship was excellent and efficient. The bed platform was built exactly as described, and the overall quality met my expectations.

C

CHEE CHONG Chang

15 days ago

They did an excellent renovation job for my Clan premise. Work includes installation of big ceiling Fan (replacement unit), strength staircase support with termite coatings and miscellaneous works for a reasonable price. Will certainly recommend to friends and those looking at this web review. 👍 👍 👍

M

MK

19 days ago

Reliable handyman that I have used and recommend

W

walter Lau

23 days ago

HDB interior pairing good & satisfaction professional attitude

A

AS2 ENGINEERING PTE. LTD

27 days ago

Professional service’s,good workmanship,and reasonable pricing. The team completed the renovation smoothly and on time. Highly recommended.

Frequently Asked Questions

How much does roof waterproofing cost in Singapore?

Aldisg's roof waterproofing services start from S$500. The final price depends on the roof size, surface condition, access requirements, existing damage and waterproofing method required. A site inspection provides a more accurate quotation based on the actual condition of the roof.

How long does roof waterproofing last in Singapore?

The lifespan of a roof waterproofing system depends on the material used, application quality, roof exposure and foot traffic. A professionally applied system can provide protection for several years, but regular inspection is recommended to identify cracking, ponding or membrane deterioration before major leaks develop.

What causes roof leaks in Singapore?

Common causes include ageing or failed waterproofing membranes, hairline concrete cracks, water ponding, gaps around pipe or cable penetrations, and blocked or damaged drainage outlets. Singapore's heavy rainfall and humidity can make existing roof defects worse and lead to recurring leaks.

What is the best roof waterproofing method in Singapore?

There is no single waterproofing method that suits every roof. PU injection grouting is suitable for targeted leaks through concrete cracks and joints, while membrane or coating systems can provide broader surface protection. An inspection helps determine which method is appropriate for the roof's condition.

Should I repair or waterproof a leaking roof?

If water is actively entering through a specific crack or joint, targeted roof leak repair may be appropriate. If the existing waterproofing has deteriorated across a wider area or leaks keep returning, broader waterproofing may provide a better long-term solution. Some roofs require both leak repair and surface waterproofing.

What is the best waterproofing for a concrete roof in Singapore?

For an RC concrete roof, the appropriate solution depends on the condition of the slab, cracks, joints, drainage and existing waterproofing. PU injection grouting can be used to seal active leaks through cracks and joints, while a membrane or coating system can provide wider surface protection.

What is the best waterproofing method for a commercial roof in Singapore?

The right method depends on the roof size, surface condition, drainage, access and existing waterproofing system. Membrane or coating systems may suit larger roof areas, while PU injection can address specific cracks and joints. A site assessment is recommended before selecting the system.

How do I stop a commercial roof from leaking?

Start with a professional inspection to identify where water is entering rather than only repairing the visible leak indoors. The roof should be checked for damaged membranes, cracks, joints, drainage outlets, penetrations and water ponding. The appropriate repair or waterproofing method can then be recommended based on the findings.

How do I choose a roof waterproofing contractor in Singapore?

Choose a contractor who inspects the roof before providing a final quotation and clearly explains the recommended waterproofing method. For commercial or high-rise properties, also check their safety procedures, Risk Assessment, Method Statement and experience with rooftop access. A clear workmanship warranty should also be provided.

Does roof waterproofing require a site inspection?

Yes. A site inspection helps identify the actual source of water entry, assess the roof's surface condition and determine the most suitable waterproofing method. It also allows the contractor to consider roof size, access, drainage and existing waterproofing before providing a final quotation.

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About the Author

Aldi Construction Pte Ltd (Aldisg)

Waterproofing & Building Maintenance Specialist in Singapore

Aldi Construction Pte Ltd is a Singapore-based contractor providing roof waterproofing, water leakage repair and building maintenance solutions for residential, commercial and industrial properties.

The Aldisg team approaches waterproofing through site inspection and proper leak diagnosis, rather than relying on surface-level repairs. Their work includes PU injection grouting, membrane and coating systems, non-hacking waterproofing, and solutions for concrete and flat roofs.

For commercial and industrial projects, the team also handles relevant Risk Assessments, Method Statements and rooftop access requirements, with trained personnel for work at height.

Areas of Expertise: Roof Waterproofing • Roof Leak Repair • PU Injection Grouting • Concrete Roof Waterproofing • Commercial Waterproofing • Industrial Waterproofing • Building Maintenance

Based in: Serangoon, Singapore

Serving: Serangoon, Farrer Park, Paya Lebar, Bugis, Rochor, Beach Road and surrounding areas

Get a Roof Inspection & Quote

If your roof is leaking, showing ponding water, or you're doing preventive maintenance before the next heavy rain season, get it looked at before the problem spreads.

Aldisg (Aldi Construction Pte Ltd) roof waterproofing contractor serving Serangoon, Farrer Park, Paya Lebar, Bugis, Rochor and Beach Road.