Torch-on Waterproofing Explained

The term Torch-on roofing is derived from the way roofers apply it. It is one of the most used waterproofing techniques that involve using a blowtorch to melt modified asphalt onto the area. Predominately used for flat and slightly angled roof, it is an excellent waterproofing solution that could last for over 20 years depending on the numbers of layers used. In this article, we will walk you through everything you need to know about torch-on waterproofing.

Technique and Material Used

Torch-on roofing involves the usage of the specially modified asphalt — bitumen. The combination of synthetic rubberized polymers and asphalt creates a perfect waterproofing material that is flexible while resisting brittleness. With proven waterproofing capabilities, this method also has special insulation characteristics that will help maintain a more stable indoor temperature. Typically, this technique begins with a layer of fiberglass felt as a base sheet for the roofing material to be torched on. Next, the bitumen layer is rolled out. A torch is involved to melt the asphalt, effectively sealing the layers via heat. Depending on needs, the last step would be to lay more layers or different type of layers depending on needs.

Advantages of the technique

High Reliability

This is a proven technique that is usable for a lot of different scenario. The torch-on process creates a surface that is perfectly waterproof. On top of that, it is puncture-resistant which means you won’t need to worry about any sudden roof leakage.


As one of the most durable materials in the market, it is able to last more than ten years depending on the number of layers used.

Does not require the removal of existing roof

Different from most waterproof techniques, the torch-on roofing can be applied on current roofs. This allows for a speedy process and the special needs of unique cases. However, it is most recommended to remove your existing roof so that the torch-on roofing will last longer.

Disadvantages of the technique

Professional installation required

Due to the special set of expertise required, torch-on roofing requires waterproofing specialist to carry out the installation. This is because it is a tedious process involving multiple layers and a blowtorch. Whenever fire is involved, it is always best to leave it to professional as they are trained to manage fire hazard risks.

Slightly costly

Due to the extensive process to apply torch-on waterproofing roofs, it is expected to be steeper in cost. However, the offset is that torch-on roofing last for a really long time (>10 years) and is extremely durable. Ultimately, it is a cost-effective long-term solution that only requires a little bit more of initial investment.

Now that you have learned all that you need to know for the torch-on waterproofing process, you are already better equipped to make an informed decision for your waterproofing needs. The first thing you should always do is to engage a waterproofing contractor in Singapore for a free consultation and quotation.