EPDM is a product consisting of three distinct monomers. EPDM is classified as a Thermoset material which means it is either fully-cured prior to being installed or that it cures during natural weathering after installation. EPDM roofs are single-ply membranes meaning there is only one ply of roofing material.
EPDM membranes are installed fully-adhered, mechanically-attached or ballasted. Fully-adhered means that the roof is "glued" to the substrate using a special adhesive. Ballasted means the membrane is loose laid over the top of the roof, sealed at all penetrations and around the perimeter, and then a ballast is put on it to hold it in place. Ballast usually consists of smooth, round, river rock 2"-3" diameter. Mechanically-attached membranes are those that use some type of screw-type fastener to secure it. The seams of all systems are sealed using either an adhesive or a splice tape.
This system offers ease of installation and usually a lower cost. Some concerns are puncture from heavy traffic, ponding water, delamination, shrinking if not properly installed, and chemical resistance.
Properly installed EPDM rubber roofs should last between 15 - 20 year