Licensed Waterproofers - Melbourne
Torch On Membrane Waterproofing Melbourne
Flat roofs, podium decks and carparks do not forgive bad waterproofing. When water shows up inside, the damage is never cheap or quick to fix. Complete Construction Service has been applying toch on membrane waterproofing Melbourne for over a decade. If you need a licensed torch applied membrane contractor, get in touch with us.
The system explained
What Is Torch On Membrane Waterproofing?
Torch on membrane is also called bitumen torch on or torch applied membrane. It’s a heat-bonded system. A modified bitumen sheet is rolled out over the prepared surface and a gas torch melts the underside as it unrolls, fusing it directly to the substrate. Thick, fully adhered, nothing to lift or peel.
The sheets come in two types SBS (styrene-butadiene-styrene) or APP (atactic polypropylene) modified bitumen. SBS stays flexible in the cold. APP handles UV and heat better, which matters on a Melbourne rooftop in summer. Both have been used on Australian buildings for decades and both are significantly tougher than standard bitumen.
At Complete Construction Service, we apply torch on membrane to AS 3740 and relevant NCC Section F requirements using quality products from manufacturers including Ardex and Sika where specified.
Where We Work
Where We Apply Torch On Membrane Waterproofing in Melbourne
Not everything needs torch on membrane, but when it does for flat roofs, podium decks, and below-ground structures — it is the system we reach for as part of our waterproofing services in Melbourne. Here is where we use it.
Know Your System
Why Choose Torch On Membrane And When to Use Something Else
Torch on membrane comes down to three things: thickness, adhesion and durability. At 3mm to 5mm thick and heat-bonded directly to the substrate, there is no delamination risk and no weak points. For exposed, high-load or below-ground applications, it is hard to beat. Done properly, a torch on waterproofing system on a flat roof in Melbourne should last 20 to 30 years.
It is not the right system for every job though. Bathrooms and laundries need liquid applied membrane under AS 3740 — the gas torch process is not suitable for enclosed interior spaces. If you are after bathroom waterproofing, our waterproofing services Melbourne page covers the full range of systems we use.
Torch on is also not a system for inexperienced contractors. Done poorly it creates fire risk during installation and adhesion failure in service. Done well it is one of the most robust waterproofing systems available. That is why who you hire matters.
How we do it
Our Torch On Membrane Waterproofing Application Process
The quality of a torch on installation comes down almost entirely to what happens before the membrane goes down. Surface prep is where most failures start not the membrane itself.
01
Substrate Assessment
We inspect the concrete slab or substrate for cracks, hollow sections, contamination and drainage fall. If falls are inadequate, water pools and that defeats the purpose of the membrane. We flag this before we start.
02
Surface Preparation
Our team cleans, repairs and primes the substrate. We fill any cracks wider than hairline and allow them to cure. We apply primers to improve adhesion and reduce the risk of blistering under the heat application.
03
Detail Work First
Upstands, penetrations, drain surrounds and corners are treated with liquid membrane or cut pieces of torch on sheet before the main field is applied. These details are where failures happen so they should get done properly before the field membrane goes on.
04
Torch Application
The bitumen torch on membrane is rolled out and the gas torch is applied to the underside as it unrolls, melting the bitumen until it flows and bonds to the primed substrate. Overlaps between sheets are torched to a full fusion no gaps, no cold laps.
05
Second Layer Coat
For high-demand applications like exposed flat roofs and podium decks , we apply a second layer of torch on sheet at 90 degrees to the first, providing double coverage and eliminating any lap alignment issues from the first pass.
06
Protection and Finishing
Depending on the application, the membrane is finished with a reflective coating, protection board, paving or ballast. On trafficable surfaces, a wearing course appropriate to the loading is applied over the membrane system.
Our team completes all work to AS 3740, 4654.2:2012 and relevant NCC requirements. Complete Construction Service holds the necessary licences and insurance to carry out torch applied membrane work commercially and residentially across Melbourne.
Where we offer
Torch On Membrane Waterproofing Across Melbourne
Complete Construction Service works on torch on membrane projects across Melbourne and its surrounds. We handle everything from single-storey flat roofs in Brighton and Bentleigh through to podium deck remediation on apartment complexes in Southbank and Docklands.
We also work with insurers and property managers on remediation jobs across Melbourne’s north and west. Like Sunshine, Footscray, Werribee where older commercial buildings are showing the age of their original waterproofing systems.
Not on that list? Call anyway.
We cover all of Melbourne and we will come out and look at any job that is right for torch on membrane.
let's work together
Get a Free On-Site Quote for Torch On Membrane Waterproofing
If you have a flat roof, podium deck, carpark or basement that needs waterproofing or one that is already leaking just give Complete Construction Service a call. We come to site, assess the substrate and the scope, and give you an honest quote on what the job actually needs.
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Frequently Asked Questions
What is torch on membrane waterproofing?
Torch on membrane waterproofing uses heat bonding, where we fuse a modified bitumen sheet to the substrate using a gas torch. As the membrane unrolls, the torch melts the underside of the bitumen, creating a direct bond with the primed surface beneath. It produces a thick, fully adhered waterproof layer with no adhesive, no fasteners, no cold laps.
What is the difference between liquid membrane and torch on membrane waterproofing?
Liquid membrane is applied by brush, roller or spray and suits internal wet areas like bathrooms, laundries and balconies. Torch on membrane is a bituminous sheet system bonded by heat, better suited to flat roofs, podium decks, basements and below-ground structures where thickness and durability are the priority. Internal wet areas use liquid membrane under AS 3740. Torch on is for external and structural applications.
Is torch on membrane waterproofing suitable for bathrooms?
Not for standard residential bathrooms. The gas torch process is not suitable for enclosed interior spaces, and liquid membrane is the compliant, practical system for internal wet areas under AS 3740. If you need bathroom waterproofing in Melbourne, our bathroom leak repair service covers the right system for that application.
How long does torch on membrane waterproofing last?
A properly installed torch on membrane system on a flat roof or podium deck in Melbourne will typically last 20 to 30 years. How long it lasts depends on the quality of installation, the number of layers, UV protection measures and whether the substrate was properly prepared. All our installations come with a 10-year workmanship warranty.
How much does torch on membrane waterproofing cost in Melbourne?
Cost depends on the size of the area, substrate condition, number of membrane layers required, access difficulty and the finish system specified. A flat roof on a residential property might start from $80 to $150 per square metre installed, with larger commercial areas generally reducing the per-square-metre rate. The only way to give you a real number is to see the job. Call 0414 060 534 for a free on-site assessment.
Do I need a licensed waterproofer for torch on membrane work in Victoria?
Yes. In Victoria, waterproofing is a licensed trade under the Victorian Building Authority (VBA). Anyone carrying out or overseeing waterproofing work on a domestic building must hold the appropriate license. Complete Construction Service holds the required licenses and insurance to carry out torch applied membrane work on both residential and commercial projects across Melbourne.
Can you apply torch on membrane over existing waterproofing?
Sometimes. If the existing membrane is fully adhered, structurally sound and compatible with the new system, torch on can be applied over the top. If the existing membrane is bubbling, delaminating or structurally compromised, it needs to come off before new work goes down. We assess the existing condition on-site and tell you honestly which approach is needed before quoting.
What is the difference between SBS and APP modified bitumen?
SBS (styrene-butadiene-styrene) modified bitumen is more flexible and handles Melbourne's cold winters without cracking. APP (atactic polypropylene) has higher UV and heat resistance, better suited to exposed flat roofs in summer. We select the right product based on the application and exposure conditions of your job.
