Torch-On Membrane vs Liquid Waterproofing: Which One for Your Roof?
Torch-on membrane and liquid waterproofing both cost RM7 to RM9 per sq ft in Malaysia in 2026 and both carry a 10-year warranty from us. Torch-on suits large, simple flat roofs with ponding. Liquid suits roofs with many pipes, aircond brackets and odd corners. The right choice depends on your slab, confirmed at a free inspection.
The short answer
Price is not the deciding factor here, because both systems fall in the same RM7 to RM9 per sq ft band. What decides it is the shape of your flat roof, how many things are bolted through it, and whether the slab holds standing water after a storm.
On a typical Malaysian shophouse roof or a car porch slab, our technician looks at three things first: ponding, penetrations and the condition of the existing layer.
How torch-on membrane works
A torch-on membrane is a bitumen-based sheet, rolled out over a primed concrete slab and heated with a gas torch so the underside melts and bonds to the surface. Each roll overlaps the next, and the laps are torched and pressed to seal them. The result is a thick, continuous sheet that handles ponding water and foot traffic well.
- Thick, factory-made sheet with consistent thickness
- Strong against standing water
- Good on large open flat roofs and car porch slabs
- Laps are the weak point if they are not properly sealed
How liquid waterproofing works
Liquid roof waterproofing is applied by roller or brush in several coats, usually with a reinforcing mesh at cracks, corners and upstands. It cures into a seamless skin with no laps, and it wraps easily around pipes, aircond brackets, solar mounting legs and parapet corners.
- Seamless, no laps to fail
- Easy around pipes, brackets and odd shapes
- No open flame on site
- Thickness depends on the crew applying enough coats
Side-by-side comparison
This is how the two compare on the kinds of roofs we inspect most in the Klang Valley, Johor and Penang.
| Torch-on membrane | Liquid waterproofing | |
|---|---|---|
| 2026 price | RM7 - RM9 / sq ft | RM7 - RM9 / sq ft |
| Our warranty | 10 years | 10 years |
| Best for | Large flat roofs, car porch slabs, ponding | Roofs with many penetrations, complex shapes |
| Seams | Overlapped laps, torched | Seamless |
| Open flame | Yes | No |
| Weak point | Badly sealed laps, upstands | Thin application, poor surface prep |
| Surface needs | Dry, clean, primed slab | Dry, clean, primed slab |
Which one fits which Malaysian roof
From what our site teams see on site, these are the usual matches. Your inspection may say otherwise once we test the slab.
| Roof | Usual choice | Why |
|---|---|---|
| Car porch slab on a terrace | Torch-on | Simple rectangle, water tends to pond near the edge |
| Shophouse flat roof with water tanks and aircond units | Liquid, or torch-on with liquid at details | Many penetrations and brackets |
| Rear kitchen extension slab | Either | Depends on falls and how it meets the main roof |
| Condo or apartment rooftop | Assessed case by case | Common property is managed by the JMB or MC under the Strata Management Act 2013 |
| Balcony or planter box | Liquid | Small area, tight corners |
Worked cost examples
Both systems use the same rate, so your budget is mainly driven by area. These figures are indicative.
- Car porch 20 x 18 ft = 360 sq ft: about RM2,520 to RM3,240
- Rear extension 20 x 15 ft = 300 sq ft: about RM2,100 to RM2,700
- Shophouse roof 1,000 sq ft: about RM7,000 to RM9,000
- Commercial or factory roofs above 5,000 sq ft: formal quotation after site survey. See commercial roofing.
What matters more than the product
Most failed flat roofs we see did not fail because the wrong product was chosen. They failed at the details: membrane that stops short of the parapet upstand, laps that were never fully torched, liquid coating applied in one thin coat, or a new aircond bracket drilled through a perfect membrane a year later.
Surface preparation is the other half. Old peeling layers have to come off, cracks have to be treated, and the slab has to be dry. In the Malaysian wet season, that means picking the right dry window, not rushing the job between storms.
Not sure which system you need? Get a free inspection
Our technician will water-test the roof, check for ponding, count penetrations and tell you which system fits, with the quotation on the spot. Prices above are indicative; the exact price is confirmed after the free inspection.
Read more about torch-on membrane and roof waterproofing, or book a free inspection.
Frequently asked questions
Which is better, torch-on membrane or liquid waterproofing?
Neither is better everywhere. Torch-on membrane handles ponding and large simple slabs very well. Liquid waterproofing is seamless and works better around pipes, brackets and odd shapes. Both cost RM7 to RM9 per sq ft and carry a 10-year warranty from us. The roof's shape and condition decide which one we recommend.
How much does torch-on membrane cost in Malaysia?
Torch-on membrane waterproofing costs RM7 to RM9 per sq ft in 2026 for flat roofs, slabs and car porches, with a 10-year warranty. A 360 sq ft car porch is roughly RM2,520 to RM3,240. Exact pricing is confirmed after a free inspection, since surface preparation and upstands vary.
Can torch-on membrane be applied over old waterproofing?
Sometimes, but only if the old layer is well bonded and sound. Peeling, blistered or brittle layers must be removed first, or the new membrane will fail with them. Our technician checks adhesion and moisture during the inspection and includes any removal in the quotation.
Can waterproofing be done during rainy season?
Yes, but only on dry days with a dry surface. Both torch-on and liquid systems need a clean, dry slab to bond. During the monsoon our site teams plan around the weather, working in morning dry windows and protecting the surface before afternoon storms.
Is liquid waterproofing suitable for car porch roofs?
It can be, especially if the porch has drain outlets, light fittings or brackets through the slab. For a simple rectangular porch where water ponds near the edge, torch-on membrane is often the better match. Both cost RM7 to RM9 per sq ft with a 10-year warranty.
Roofing guides
- ComparisonBest Roof Type for Malaysia Weather (2026 Guide)Best roof type for Malaysia's heat and monsoon rain: stone-coated tiles, PU-foam metal deck or concrete tiles…
- ComparisonMetal Roof vs Concrete Tiles Malaysia: Which to PickMetal roof vs concrete tiles in Malaysia: PU-foam metal deck RM14-RM22/sq ft vs concrete tiles RM9-RM15/sq…
- All guides