Protect Your Roof Before the Damage Starts
Your roof is Singapore’s first line of defence against 2,166mm of rain per year, nearly double the global average. A properly waterproofed roof handles all of it without letting a drop through. An ageing membrane or failing sealant does not announce itself until water is already inside your building.
General Waterproofing & Service has been protecting roofs across Singapore since 2007. BCA-registered. Free site inspection. Written workmanship warranty on every project.
Roof Waterproofing Systems We Apply
The right system depends on your roof type and its current condition. We assess before we recommend.
Torch-On Bituminous Membrane: RC Flat Roofs
A modified bituminous sheet is heat-fused directly to the roof deck, creating a thick, continuous waterproof barrier. The most widely specified system for Singapore’s RC flat roofs has proven performance against ponding water and sustained monsoon rainfall. Service life: 10 to 15 years.
- Best for: terrace houses, semi-detached, bungalows, commercial roof decks
- Thickness: 3mm to 4mm, high resistance to ponding water pressure
- Requires full substrate drying before application, with moisture content below 6%
Liquid-Applied Polyurethane (PU) Membrane: RC & Concrete Roofs
A two-component system that cures into a seamless, flexible, elastomeric membrane. No joints, no weak points across the field area. Conforms to complex geometry and accommodates Singapore’s daily thermal movement without cracking. Service life: 7 to 10 years.
- Best for: roof terraces, RC ledges, balcony overhangs, surfaces with multiple penetrations
- Seamless application eliminates the overlap failures common in sheet systems
- Must be applied below 85% relative humidity, critical in Singapore’s climate
Acrylic Elastomeric Coating: Metal Roofs
A three-layer system, rust inhibitor primer, elastomeric mid-coat, UV-resistant topcoat that bonds to metal substrates, accommodates significant thermal movement, and prevents corrosion from progressing. Applied without removing existing metal sheets. Service life: 5 to 7 years, renewable with a maintenance topcoat.
- Best for: zinc, aluminium, and Zincalume roof sheets on residential and industrial buildings
- Rust must be fully removed mechanically before primer, the most common failure cause if skipped
Penetrating Sealant & Joint Treatment: Tiled Pitched Roofs
Pitched roofs drain efficiently by gravity; what fails are the ridge cappings, valley joints, verge flashings, and penetration seals. We treat these specific vulnerable points with polyurethane or silicone sealant and a flexible backing rod. No tile removal required in most cases. Service life: 5 to 8 years at treated joints.
- Best for: clay tile, concrete tile, and zinc sheet pitched roofs on landed properties
- Targeted treatment at actual failure points, not a blanket coat of the whole roof
Which System Is Right for Your Roof?
| Torch-On | Liquid PU | Acrylic | Tile Sealant | |
|---|---|---|---|---|
| Roof Type | RC flat | RC flat/terrace | Metal | Tiled pitched |
| Service life | 10–15 yrs | S$2,500 | S$4,500 | Number of coats and penetrations |
| Ponding resistance | Excellent | S$2,000 | S$4,000 | Rust treatment extent |
| Handles roof movement | Moderate | S$1,200 | S$2,800 | Ridge metres and tile replacement |
| Handles roof movement | Medium–High | S$900 | S$2,000 | Affected area and access |
Not sure which applies to your roof? Our free site inspection confirms the right system and whether repair or full waterproofing is needed first.
Active leak already? See: Roof Leakage Repair Singapore
Our Roof Waterproofing Process
Free site inspection
Moisture meter readings confirm substrate condition. We never quote without seeing the roof.
Written diagnosis & itemised quotation
Exactly what we found, what we recommend, and what it costs. Line by line.
Surface preparation
Existing failed material removed, cracks treated, primer applied. The stage that determines service life.
Waterproofing application
Correct system applied in specified coats with manufacturer curing times observed. No shortcuts.
Detailing
Parapet upstands, drain surrounds, pipe penetrations, and expansion joints. Where 80% of failures originate.
Post-application water test & warranty documentation
Post-application water test & warranty documentation; verified result in writing before we leave the site.
Important: Waterproofing over a wet substrate or end-of-life membrane fails within months regardless of system quality. If our inspection finds these conditions, we recommend drainage correction or full membrane removal first and explain exactly why.
Roof Waterproofing Cost in Singapore
Roof waterproofing cost in Singapore depends on the type of roof, the existing surface condition, the waterproofing system required, and whether old membrane layers need to be removed before new works can begin. A flat RC roof, metal roof, tiled roof, or localised repair will usually involve different preparation, materials, labour, and access requirements.
The figures below are indicative only. Final pricing should be confirmed after a site inspection, as water seepage may be caused by failed membranes, ponding, cracked joints, blocked drainage, or hidden substrate moisture.
| Scope | Low | Typical | High | Main Variable |
|---|---|---|---|---|
| RC flat roof torch-on, around 55 sqm terrace house | S$1,600 | S$2,900 | S$5,200 | Membrane removal required |
| RC flat roof liquid PU, around 55 sqm | S$1,400 | S$2,500 | S$4,500 | Number of coats and penetrations |
| Metal roof acrylic system, around 100 sqm | S$900 | S$2,000 | S$4,000 | Rust treatment extent |
| Tiled roof joint sealant treatment | S$500 | S$1,200 | S$2,800 | Ridge metres and tile replacement |
| Localised patch repair | S$400 | S$900 | S$2,000 | Affected area and access |
Why Singapore Property Owners Choose General Waterproofing
Accurate Diagnosis Before Any Repair
Effective waterproofing begins with identifying the true source of the leak. Our specialists conduct thorough inspections to assess cracks, failed membranes, pipe penetrations, and drainage issues before proposing any solution. This prevents guesswork and ensures repairs are done right the first time.
High-Quality Waterproofing Systems Built for Singapore Weather
Singapore’s heavy rainfall, heat, and humidity can accelerate roof and wall deterioration. We use waterproofing systems that are specifically selected for local conditions, including liquid membranes, PU injections, and torch-on membranes that withstand prolonged moisture and UV exposure.
Skilled Waterproofing Specialists With Proven Workmanship
Our team in Singapore comes with years of hands-on experience and stays aligned with recognised industry standards, including Singapore’s Waterproofing Accreditation Scheme. In addition, the scheme is supported by the Singapore Concrete Institute (SCI), which promotes professional competency and proper waterproofing practices across the industry.
Project Case Study: RC Flat Roof, Terrace House, Yishun
This case study shows how a recurring roof leak at a terrace house in Yishun was traced back to an ageing waterproofing membrane, poor drainage, and repeated patch repairs that did not address the underlying issue. The project required full removal of the failed membrane, proper drying of the substrate, drainage correction, and a new waterproofing system suited to the roof condition.
The Problem
The homeowner had experienced recurring ceiling leakage in the master bedroom across multiple monsoon seasons. Previous repair attempts had only provided short-term relief, with an acrylic coating and a torch-on patch failing within months. By the time the roof was inspected again, the leak had become a recurring issue rather than an isolated defect.
What We Found On Site
The existing membrane had reached the end of its service life, with widespread blistering and signs of trapped moisture between layers. Blocked drains had also caused chronic ponding, which increased pressure on vulnerable edges and weak points. Moisture readings showed that the substrate remained damp beneath the visible surface.
The Root Cause
The main issue was not just surface cracking. The older membrane had already failed, but previous repairs were applied over unstable layers instead of removing the defective system. Ponding from blocked drains further accelerated deterioration, causing the patched areas to delaminate within months.
The Repair Method
The repair involved full membrane removal, controlled substrate drying, drainage correction, and installation of a two-layer torch-on waterproofing system. Parapet upstands were extended to improve protection at vertical junctions, where water ingress often occurs when detailing is insufficient.
Cost and Outcome
The total project cost was S$4,200. Following the repair, there was no recurrence through two full monsoon seasons. A 12-month follow-up moisture reading showed the roof substrate had dried to 38% RH, confirming that the previous trapped moisture issue had been resolved.
5-Star Waterproofing Services in Singapore – Client Feedback
Our reputation is built on consistent results, reliable workmanship, and long-term solutions. As a trusted provider of waterproofing services, we are proud to receive positive feedback from homeowners, property managers, and businesses who rely on our team to resolve their leakage concerns professionally and efficiently.
Before & After Roof Waterproofing
Our completed projects in Singapore highlight the visible transformation that comes with professional roof waterproofing repair. From addressing cracks and leaks to restoring surface protection, each project is carried out with precision and durability in mind.
Residential Roof Restoration (Singapore Landed Home)
This landed home experienced visible seepage and algae buildup due to prolonged exposure to rain. After surface preparation and the application of liquid-applied membranes, the roof achieved full waterproof coverage and enhanced UV resistance.
Flat Concrete Roof Reconditioning (Commercial Property)
This commercial building faced ponding and hairline cracks on its flat roof surface. Our team performed thorough cleaning, crack sealing, and coating using a reinforced membrane system to ensure long-term water resistance and weather durability.
Each project is completed following General Waterproofing’s proven waterproofing process, ensuring that every roof is inspected, treated, and finished with care.
Frequently Asked Questions About Roof Waterproofing in Singapore
Can waterproofing be done on any roof type?
Yes! We offer customised roof waterproofing for flat, pitched, concrete, metal, and tiled roofs. Got questions? Contact us today for expert advice tailored to your roof type.
How long does roof waterproofing last in Singapore?
The lifespan of roof waterproofing in Singapore depends on factors like the type of roof, materials used, and environmental conditions. Generally, a well-maintained waterproofing system can last between 5 to 20 years. Regular inspections and maintenance can significantly extend its lifespan.
What is the process of waterproofing a roof using a membrane?
Waterproofing a roof with a membrane involves a thorough inspection, surface preparation, and repair of any damage. Then, a specialized waterproofing membrane is applied to create a seamless, watertight barrier. This membrane can be torch-applied, self-adhesive, or liquid-applied, depending on the specific needs of the roof.
Will waterproofing affect my roof’s appearance?
Our roof waterproofing is designed to be subtle and blend seamlessly with your roof, preserving its original appearance while providing strong, long-lasting protection against leaks and weather damage.
How much does roof waterproofing cost in Singapore?
The cost of roof waterproofing in Singapore depends on several factors such as roof size, material type, and the extent of damage or preparation needed. Additional considerations like accessibility, coating system, and repair complexity may also influence the final quote.
To receive an accurate estimate tailored to your property’s needs, please contact us for a free on-site inspection and quotation. Our team will assess your roof condition and recommend the most cost-effective solution for long-lasting protection.
Ready to Protect Your Roof with General Waterproofing & Service?
Protect your property from costly water damage with General Waterproofing, your trusted waterproofing specialist in Singapore. Whether you need a quick inspection or a full waterproofing service, our team is ready to assist.
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