EPDM (ethylene propylene diene monomer) is a roofing material that is best known for its durability and suitability with flat roofs, so if that's what you need for your roof, it's worth considering.

and five types of roof coverings: asphalt or fiberglass shingles, concrete or clay tile, metal, and two flat-roof styles — built up or membrane — more commonly used in commercial buildings. Yaworsky ...

Second, the frame creates a flat and straight surface even when the shingles are badly curled or the roof ridge is bowed.