These are called thermoset, vulcanized or cured membranes. They are characterized by their inability to form seams by any method other than using compatible adhesives. The most commonly used membrane in this category is a synthetic rubber EPDM (ethylene propylene diene monomer). The sheet is very elastic. Used since the 1960's, EPDM currently has the largest market share of all single plies nationwide.

Benefits

High Resistance to UV degration, ozone, heat aging and low temperatures. Low maintenance. Lightweight, attractive.