Direct answer: Torch-on waterproofing is a heat-bonded bituminous membrane for flat concrete roofs. It is suitable when the slab and falls are stable, outlets work and the substrate can be safely prepared; it should not be used to hide active structural movement or trapped moisture.
This guide explains the Full Torch-On Membrane Waterproofing scope under roof repair services. The published starting price is RM 26 / sq ft. A site-specific quotation should confirm measurements, preparation, materials, access and related repairs rather than treating the starting rate as a fixed total.
When This Service Is the Right Choice
The service is appropriate when inspection confirms that the existing property and surrounding construction can support the proposed work. Visible symptoms alone do not prove the cause. In Kuala Lumpur and Selangor, occupied areas, parking or loading access, condominium management rules and permitted working hours may affect planning and scheduling.
What Should Be Checked Before Work
- Crack movement, hollow screed and previous coating adhesion.
- Falls, ponding depth and outlet capacity.
- Upstands, parapets, pipe penetrations and door thresholds.
- Safe flame use near services, timber and occupied spaces.
Compare the Available Approaches
| Approach | When it makes sense |
|---|---|
| Local patch | a small puncture with sound surrounding membrane. |
| Full membrane | widespread ageing or a bare, suitable flat roof. |
| Investigate first | moving cracks, wet screed or persistent ponding. |
Choosing the least expensive option without checking its limits can cause repeat work. The quotation should explain why the selected approach suits the substrate, dimensions and intended use.
Typical Work Process
- Survey and moisture-check the roof, outlets and details.
- Remove loose systems and repair stable cracks or screed defects.
- Prime the dry, clean substrate with the specified compatible primer.
- Torch-bond the specified layers with staggered, fully sealed laps.
- Finish upstands and outlets, inspect laps and protect the membrane.
Preparation and sequencing matter. Existing defects, unstable supports, incompatible materials or damaged substrates should be corrected before they are concealed. Protect occupied rooms, common corridors and completed finishes throughout the work. At handover, test operation and inspect edges, fixings, joints and access points—not appearance alone.
Common Mistakes to Avoid
- Applying membrane over a damp or dusty substrate.
- Stopping the membrane flat at a wall instead of forming an upstand.
- Reducing overlap width around outlets and corners.
- Using open flame without a fire plan and extinguisher.
A competent inspection should distinguish a serviceable component from a system that has reached the point of replacement. Ask for assumptions and exclusions to be written down, especially where concealed conditions cannot be confirmed until work opens the area.
Cost and Quotation Factors
- Published starting price: RM 26 / sq ft
- Measured roof area including upstands and wastage.
- Substrate removal, screed and crack preparation.
- Membrane specification, layers and surface protection.
- Access, flame controls and outlet detailing.
The parent service publishes a 10-Year Membrane & Workmanship Warranty, subject to its stated scope and terms. Confirm in writing whether it applies to this exact work, materials supplied by the customer and pre-existing defects.
Safety, Access and Maintenance
Do not bypass manufacturer instructions, building management requirements or safe access arrangements to save time. Keep product references and care instructions after handover. Routine cleaning and early attention to movement, moisture, corrosion or loose hardware usually make local repairs simpler.
Frequently Asked Questions
Is torch-on suitable over old tiles?
Not automatically. Bond and falls must be assessed; loose tiles, hollow bedding and trapped moisture usually require removal or another designed system.
Does a new membrane fix ponding?
No. Membrane resists water entry, but inadequate falls and undersized or blocked outlets should be corrected before waterproofing.
Why are upstands important?
They carry waterproofing above the expected water level at walls and penetrations, where many flat-roof leaks begin.
Request a Site-Specific Quotation
Send wide-angle and close-up photos, approximate measurements, property type and the symptom or outcome required. KL Servis Rumah can assess the scope for properties in Kuala Lumpur and Selangor without assuming that every site needs the same solution.