EDPM stands for ethylene propylene diene monomer. It’s a long and complicated name for what is a synthetic rubber product. EDPM is made in the lab and has a number of applications apart from roofs. You’ll find it in other products such as seals around the windows in your car, pond liners, electrical insulation and garden hoses. EDPM is also used to make brightly coloured playground surfaces. Just like rubber, EDPM is flexible and can be bent and twisted into any shape.