American Society for Testing and Materials (ASTM). Current edition approved Feb. 1, 2008. Published March 2008. Originally approved in 1987. Last previous edition approved in 2004 as D4637 – 04. 4 p. This specification covers flexible sheet made from ethylene-propylene-diene terpolymer (EPDM) intended for use in single-ply roofing membranes exposed to the weather. The tests and property limits used to characterize the sheet are values to ensure minimum quality for the intended use. The sheet may be non-reinforced, fabric- or scrim-reinforced, or fabric-backed vulcanized rubber sheet.