Torch-On Waterproofing Membrane and Liquid Applied Waterproofing Membrane are two of the most commonly used waterproofing systems for roofs, balconies, and concrete structures. Both prevent water penetration but differ in installation method, durability, flexibility, cost, and maintenance.
Below is a clear comparison.
Torch-On Waterproofing Membrane
Comes in bitumen sheet rolls (usually 1m x 10m).
Installed using a gas torch to heat the membrane and bond it to the surface.
Requires skilled workers and hot works safety precautions.
Liquid Applied Waterproofing Membrane
Applied like paint using roller, brush, or spray.
Usually requires 2–3 coats with curing time between layers.
No open flame required, making it safer for certain sites.
Summary:
Torch-on = heat-applied sheet
Liquid membrane = coating system.
Torch-On Membrane
Installed in overlapping sheets, creating seams.
If seams are not installed properly, water may penetrate through gaps.
Liquid Applied Membrane
Forms a seamless continuous waterproof layer.
No joints or overlaps that could fail.
Summary:
Liquid membranes reduce leak risk at joints.
Torch-On Membrane
Thick bitumen sheet with reinforcement.
Very strong and resistant to mechanical damage.
Common lifespan 15–20 years depending on maintenance.
Liquid Applied Membrane
More flexible but thinner.
May be more vulnerable to physical damage in heavy traffic areas.
Some systems last 20–30 years when properly installed.
Summary:
Torch-on = stronger sheet
Liquid = flexible but may need protection.
Torch-On Membrane Best For
Flat concrete roofs
Commercial buildings
Large surfaces
Areas needing strong membrane protection
Liquid Applied Membrane Best For
Complicated roof shapes
Pipe penetrations and joints
Gutters and small areas
Renovation waterproofing
Liquid systems adapt better to irregular surfaces.
Torch-On Membrane
Usually cheaper material cost.
Faster installation for large areas.
Liquid Applied Membrane
Higher material cost but may provide longer warranty and lower maintenance.
Torch-On Membrane
Requires open flame (gas torch).
Fire risk if done in sensitive areas.
Liquid Membrane
Cold applied system (no fire risk).
| Feature | Torch-On Membrane | Liquid Applied Membrane |
|---|---|---|
| Installation | Gas torch heated sheets | Brush/roller coating |
| Seam | Has joints and overlaps | Seamless layer |
| Strength | Very durable | Flexible |
| Best Area | Large flat roofs | Complex surfaces |
| Cost | Lower initial cost | Higher but longer life |
| Safety | Fire risk during installation | No flame |
✅ Simple Conclusion
Torch-On Waterproofing Membrane
Best for large concrete roofs and heavy-duty waterproofing.
Liquid Applied Waterproofing Membrane
Best for complex areas, renovations, and seamless waterproofing.
In many projects, contractors combine both systems — torch-on for the main roof and liquid membrane for edges, drains, and details.
✅ If you want, I can also explain:
Which waterproofing is better for concrete roof in Malaysia climate (KL / Selangor)
When contractors should use Torch-On instead of Liquid Membrane.
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