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Materials

What is Modified Bitumen?

Roofing Glossary · Materials

Definition

A factory-reinforced asphalt roofing membrane modified with APP (atactic polypropylene) or SBS (styrene-butadiene-styrene) polymers to improve flexibility, temperature resistance, and elongation. Used on low-slope roofs, modified bitumen is installed in two plies — a base sheet and a cap sheet — using torch application, cold adhesive, or self-adhering methods. It is more durable than traditional built-up roofing and easier to install than EPDM.

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