During the application of torch on roofing, an actual flame produced from a propane torch is required. Ultimately, the installation process requires modified bitumen sheets being rolled onto the roofing surface and then being heated so that they can property adhere to that surface. At the correct temperature, the seams between the sheets essential melt together and create a waterproof, sealed surface over your roof. Torch on roofing is one of the most common roofing applications for flat, commercial roofs as it is effective, affordable, and durable. Let’s take a closer look.
The membrane of torch on roofing is composed of bitumen – essentially asphalt that has been treated with rubber or plastic. One of the key benefits of torch on roofing and the modified bitumen material it utilizes is that it expands and contracts with weather changes so that it is less likely to crack. In fact, torch on roofing is highly durable in both hot and cold climates so it provides effective roofing protection even after many years and seasonal changes. As briefly introduced, torch on roofing materials contain either rubber or plastic. While all torch on systems include bitumen – an asphalt compound that is highly durable and affordable and present in a wide range of roofing systems including shingled roofs. Asphalt is very strong and when combined with a polymer to make modified bitumen, the torch on roofing systems is born.
There are several different polymers that may be used in modifying the bitumen including atactic polypropylene (APP) which is a type of plastic. These torch on roofs are flexible and can tolerate both heating and cooling. Styrene butadiene styrene (SBS) is another polymer used in modified bitumen, but this is a type of rubber. Featuring a lower melting point than APP, SBS have multiple installation methods – torch on, self-adhered, and cold-processed.
Additionally, the two main types of torch on roofing are defined by the number of layers in the roofing systems – either two- or three-layer systems. Each of these systems feature base and cap sheets, but as you would expect the three-layer system has an extra cap sheet. In addition to the base sheet, the three-layer systems have a smooth cap sheet, but the system is finished with a granule cap sheet. This extra sheet makes the roof more durable while also improving fire resistance and energy efficiency.
Torch on roofing systems are popular choices for flat roofs for many reasons. Among the advantages of torch on roofs is their water resistance. Additionally, these roofs are suitable for any climate because they can adapt to changing temperatures. The long lifespan of these roofs ultimately owes to their adaptability – even during snowy weather, torch on roofs maintain water resistance while in warmer climates these roofs also provide exceptional UV resistance while reflecting sunlight to maintain building temperatures.