Two-ply elastomer technology gives you waterproofness and weather resistance. It’s also ideal for roofs that need to stand up to a certain amount of traffic (e.g., for air-conditioning and other equipment maintenance). The elastomer membrane is made up of a base layer, generally bitumen and styrene-butadiene-styrene (SBS) polymer covered with an aggregate finishing material resistant to UV radiation. The result is a protected bitumen with a longer service life. It’s also light and works for all types of roofs, whether flat, low-slope, or inverted. It can be installed and either mechanically attached or glued.

A well-designed and installed modified bitumen roof can have a service life of 30 years. Although the aggregate layer is normally subject to a degree of surface wear from wind and traffic without affecting waterproofness, it’s always best to check with an expert if corrective measures are necessary.