Ethylene Propylene Diene Monomer is a single-ply membrane that consists of a synthetic rubber compound that allows it to be flexible. EPDM has been used on commercial roofing facilities since the 1960s and is considered a time-tested option.
With EPDM, you have an option of choosing from 45, 60, or 90 mils thickness and either black or white for the color. While TPO has a natural white color, EPDM results in a dark gray or black color for your roof. The darker color is not helpful in reflecting UV rays; it does retain heat for those in cooler weather.