EPDM (ethylene propylene diene monomer) is a black rubber membrane with a 25-year track record in New England. It is durable, easy to repair, and performs well in extreme temperature ranges. TPO (thermoplastic polyolefin) is a white or light-colored membrane that reflects solar heat, reducing cooling costs on sun-exposed flat roofs. TPO has heat-welded seams that are stronger than EPDM’s adhesive seams. Both are excellent systems — the right choice depends on your building’s drainage, sun exposure, foot traffic, and budget. Master Roofers will recommend the appropriate system at your free estimate.