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CertainTeed Roofing – Low – Slope
750 E. Swedesford Road
P.O. Box 860
Valley Forge, PA 19482
Tel: (800) 233-8990
Fax: (610) 341-7940
Email: building.solutions@saint-gobain.com
Web site: http://www.certainteed.com

APP and SBS Modified Bitumen

In the 1970s technological advances in asphalt sciences originating in Europe led to the development of modifiers such as APP (atactic polypropylene) and SBS (styrene-butadiene-styrene) which, when added to unblown (unoxidized) asphalt, impart either plastic (APP) or rubber (SBS) characteristics. These additives provide enhanced performance characteristics to traditional asphalt, and when coupled with reinforcements such as polyester (superior elongation abilities) or fiberglass (high tensile strength) create high performance roof membranes.

APP modified bitumen membranes are self-adhering when heated using a roofing torch. SBS modified bitumen membranes can be formulated for torch application, but are more commonly applied using hot asphalt or cold SBS modified bitumen adhesive. The result is a BUR system with significantly enhanced performance capabilities. Continuing improvements in technology have also resulted in self-adhering SBS roof membranes.

When an SBS or APP cap sheet is combined with traditional BUR base sheets and interply sheets, the result is a "hybrid" roof offering the best of both systems, multiple plies and superior performance and longevity.

All of these systems are excellent roofing choices for industrial, commercial, institutional and residential low slope roofing. In choosing, factors such as site access, structural load, finished appearance, desired warranty and performance criteria should all be considered. Your CertainTeed commercial roofing territory manager can help with more information.

BUR materials are applied with hot asphalt or cold adhesives; SBS can be formulated for hot asphalt, cold adhesive, self-adhesive or torch application; APP membranes are typically torch applied only.




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