Understanding roof membranes

By Polyglass. 

Learn to pick the best membrane for your project by understanding the two basic types of modified bitumen membranes available.  

Modified bitumen roofing membranes are modern roofing membranes heralded for their variety of both type and composition and usages on the job. There are two main types to choose between, APP membranes and SBS membranes. These both were developed in Europe and gained traction in the United States in 1978. By the 1990s, Polyglass had led the industry by developing high-quality, self-adhered versions of these membranes, using ADESO® Technology. 

Overall, APP membranes are made of plastomeric and contain atactic polypropylene, which makes the membrane more rigid post-installation. SBS membranes are a synthetic rubber material called styrene-butadiene-styrene. This means they are far more flexible than APP membranes. These different materials and uses mean that their application process and overall characteristics are different. Before choosing your membrane, make sure you understand the differences between them. 

Installing APP and SBS membranes 

SBS membranes can be applied by heat-welding, hot-mop, cold-process adhesive, self-adhering membranes and can also be mechanically attached. APP membranes can be heat-welded or ADESO self-adhered. 

Heat-welding involves heating the membrane with a hot air welding gun until the compound starts to melt and then adhering it to the roof’s surface. APP and SBS membranes have slightly different reactions to this process. APP membranes melt at higher temperatures, giving them a more fluid consistency and making them easier to work with. SBS membranes have a lower melting point but become stickier when exposed to sufficient temperatures. 

These different characteristics make APP and SBS membranes have different advantages regarding how they are used. APP membranes are used more often on smaller roofing areas because they flow more easily. SBS membranes can tolerate much lower temperatures, making them ideal for cold-weather areas. They also take less time to install and last longer. 

Self-adhered membranes can be installed quickly and easily without the need for unsafe techniques such as torch application. Instead, sheets of self-adhered membranes have adhesive bottom layers that can be fixed to the roof in overlapping layers. Polyglass’ ADESO Self-Adhered Technology is a great example of these types of membranes. 

Polyglass APP and SBS membranes 

Polyglass’ innovative ADESO Self-Adhered Technology is featured in our industry-leading APP and SBS membranes. These membranes feature a dual-compound top layer facing the weathering side and a powerful adhesive bottom layer for easy and effective application. 

Pioneering technologies such as FASTLap® and SEALLap Ultra® help create strong seams to yield a completely watertight roofing system. Polyglass’ range of specialized APP and SBS membranes has been developed over decades of experience. Let’s take a closer look at two of Polyglass’ most innovative membranes. 

Polyfresko APP and SBS Membranes  

Polyglass’ range of Polyfresko APP and SBS membranes feature CURE Technology®, which provides a highly reflective surface for excellent protection from ultraviolet rays. The Polyfresko range is available as both self-adhered and heat-welded membranes. 

Elastoflex SA P Polar Base and Cap Sheets 

For any roofing projects in cold weather environments, Polyglass’ Elastoflex SA P Polar Base and Cap Sheets are an ideal membrane choice. These self-adhered SBS membranes feature high-performance fiberglass reinforcement to create a stable and insulated roofing system. 

Browse our extensive range of high-quality APP membranes and SBS membranes. 

Original article source: Polyglass