Torch on bitumen waterproofing has been a waterproofing membrane in Australia since 1940. Known today as "Torch on", this waterproofing membrane is highly effective and extremely durable for our Australian climate.
In essence, a waterproofing membrane is applied to flat, smooth surfaces. This membrane is made out of extremely sticky and viscous organic liquids, with bitumen as the key ingredient. The surface must be sound, primed, and completely clean before application to ensure effective membrane waterproofing.
The membrane is then applied by being “torched on” or heat-fused to the underlying surface. This creates a powerful watertight seal.
This technique is often used on flat roofs to prevent water leaks, but it can be used for a variety of applications in both residential and commercial buildings, such as roof slabs, planter boxes, balconies and patios and foundation or retaining walls.
Torch on waterproofing is a flexible membrane containing bitumen and a variety of polymers.
It can contain asphalt in one of two forms:

Torch on waterproofing is one of the most reliable and proven waterproofing systems available for protecting buildings and structures against water ingress. Widely used throughout residential, commercial, industrial, and civil construction projects, torch on membranes provide exceptional durability, flexibility, and long-term waterproof performance.
At Remseal, we specialise in torch on waterproofing in Sydney, providing comprehensive waterproofing solutions for roofs, balconies, basements, retaining walls, podium decks, planter boxes, and below-ground structures.
Unlike many waterproofing contractors, Remseal adopts a diagnostic-led approach, investigating the cause of water ingress before recommending the most appropriate waterproofing solution.
Torch on waterproofing is a membrane system consisting of modified bitumen sheets that are heat-fused to a prepared substrate using a controlled torch application process.
The membrane forms a continuous waterproof barrier that prevents moisture penetration while maintaining flexibility to accommodate structural movement and environmental exposure.
Torch on membranes are commonly used because of their:
When correctly installed, torch on waterproofing systems can provide decades of protection against water ingress.
Modern torch on waterproofing membranes generally consist of modified bitumen combined with reinforcing polymers to improve performance and flexibility.
SBS Modified Bitumen Membranes
Styrene Butadiene Styrene (SBS) membranes are rubber-modified waterproofing systems designed to provide superior flexibility and crack-bridging capabilities.
SBS membranes are commonly used where structural movement or temperature fluctuations are anticipated.
APP Modified Bitumen Membranes
Atactic Polypropylene (APP) membranes are plastic-modified bitumen systems that provide excellent resistance to UV exposure, heat, and environmental ageing.
These membranes are commonly used on exposed roofing systems and commercial waterproofing applications.
Torch on waterproofing is suitable for a wide range of applications, including:
Basement Waterproofing
Below-ground structures are exposed to hydrostatic pressure and groundwater intrusion. Torch on membranes provide robust protection against water ingress in basements, underground car parks, lift pits, and foundation structures.
Roof Waterproofing
Flat roofs and low-pitched roof structures benefit from torch on membrane systems due to their durability and ability to create a seamless waterproof barrier.
Balcony Waterproofing
Balconies are constantly exposed to rain, temperature fluctuations, and UV radiation. Torch on waterproofing provides reliable long-term protection for balcony structures.
Retaining Walls
Retaining walls require waterproofing systems capable of resisting moisture penetration and hydrostatic pressure from surrounding soils.
Podium Decks and Planter Boxes
Torch on membranes are frequently specified for podium decks, landscaped areas, and planter boxes where waterproof integrity is critical.
While torch on membranes are highly durable, failures can occur when the underlying causes of water ingress are not properly identified.
Common causes of waterproofing failure include:
At Remseal, we believe that replacing a membrane without understanding why it failed can lead to recurring leaks and unnecessary repair costs.
What separates Remseal from many waterproofing companies is our commitment to investigation and diagnosis before recommending repairs.
Prior to undertaking torch on waterproofing works, our team may conduct:
Waterproofing Investigations
We identify the source of water ingress and assess how moisture is migrating through the structure.
Leak Detection
Advanced leak detection techniques assist in locating concealed defects and membrane failures.
Moisture Assessments
Moisture investigations help determine the extent of water penetration and identify affected building elements.
Drainage Analysis
Many waterproofing failures are caused by inadequate drainage systems rather than membrane defects alone.
Structural Assessments
Cracks, movement joints, and construction defects are carefully evaluated to ensure the selected waterproofing solution addresses the root cause of the problem.
This diagnostic-led process allows us to recommend the most effective and cost-efficient repair strategy for each project.
Every building presents unique waterproofing challenges.
Following our investigation, Remseal may recommend:
Our goal is to provide long-term waterproofing performance rather than temporary repairs.
With more than 43 years of waterproofing and remediation experience, Remseal has built a reputation for delivering practical, reliable, and long-lasting waterproofing solutions throughout Sydney.
Our process focuses on:
Investigation
Identifying the source of water ingress.
Diagnosis
Determining why the waterproofing system failed.
Recommendations
Providing multiple repair options where appropriate.
Remediation
Implementing proven waterproofing solutions tailored to the structure.
Long-Term Protection
Delivering waterproofing systems designed for durability and performance.
When you engage Remseal, you're partnering with a team of waterproofing investigation and remediation specialists dedicated to protecting your property from water damage.
We have the tools to locate and identify the main cause, and with our extensive experience we provide the best waterproofing solution that lasts.
Totally waterproof
The bituminous membrane does not absorb any water at all, making it a resilient barrier to water and damp.
Tough
The membrane is reinforced with polyester or fiberglass and is available in several thicknesses. The material itself lasts for a long time.
Flexible
All structures experience some level of movement and the membrane is flexible enough to adjust to this.
Versatile
A number of mineral finishes allow you to adapt the appearance of the waterproofing to your structure’s style.
Eco-friendly
To top it off, it’s non-harmful to the environment. Bitumen is a non-toxic, organic hydrocarbon (created from crude oil) and it does not generate greenhouse gasses.
Remseal have been using the environmentally friendly torch method of waterproofing for the past 35 years. To enjoy the full potential of this technique, it is crucial to have the right team who will use the best materials and prep surfaces correctly for seamless adhesion.
Contact REMSEAL for all Torch On Waterproofing needs, questions, quotes, or advice.
Remseal is a leading provider of basement waterproofing services in Sydney, specializing in torch-on waterproofing solutions. Torch-on waterproofing is a method that involves applying a bitumen-based membrane to the surface of the structure using a torch. This process creates a robust and impermeable barrier against water infiltration, ensuring long-lasting protection for basements and other below-ground structures.
The torch-on waterproofing system used by Remseal is highly effective in preventing water penetration and dampness, which are common issues in basements. This method is particularly suitable for Sydney's diverse climate, where heavy rains and fluctuating weather conditions can pose significant challenges to building integrity. By choosing torch-on waterproofing, property owners can safeguard their basements against leaks, mold growth, and structural damage caused by water ingress.
One of the primary advantages of torch-on waterproofing is its durability. The bitumen membrane, when properly applied, can last for decades, offering superior resistance to wear and tear compared to other waterproofing methods. Additionally, the torch-on technique allows for seamless application, reducing the risk of weak points where water could potentially seep through. This makes it an ideal solution for protecting large surface areas and complex structures with numerous joints and connections.
Remseal’s team of experienced professionals ensures that each torch-on waterproofing project is executed with precision and attention to detail. They conduct thorough assessments of the site conditions and tailor the waterproofing system to meet the specific needs of each client. This customized approach guarantees optimal performance and longevity of the waterproofing solution.
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