APP vs. SBS Roof Membranes

When installing a new roof system, there are two main types of modified bitumen roofing membrane to choose from: APP membranes and SBS membranes. These two types of membranes have different applications and characteristics, which we’ll explore in this blog post.

What are APP and SBS Membranes?

APP and SBS membranes are different types of modified bitumen roofing membranes. To create these variations, other materials are combined with the modified bitumen base to produce different properties.

  • APP membranes are plastomeric and contain atactic polypropylene, a type of plastic that makes the membrane more rigid once applied.
  • SBS membranes are made using styrene-butadiene-styrene, a type of synthetic rubber. SBS membranes are elastomeric, making them more flexible than their APP counterparts

APP and SBS membranes started being used widely in the United States in 1978 after originally being developed in Europe. Fast-forward to the 1990s, and Polyglass became the first company to develop these high-quality self-adhered APP and SBS membranes thanks to its revolutionary ADESO® Technology.

SBS Membranes

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, and for more tips on commercial roofing, be sure to sign up for our newsletter below.