TPO stands for thermoplastic polyolefin, a single-ply roofing membrane that covers the surface of the roof. The name is a bit misleading because rather than being a plastic, TPO is actually one of a few different types of rubber, usually a blend of polypropylene and ethylene-propylene rubber.
PVC roofing or polyvinyl chloride is a single-ply roofing solution used on commercial or industrial roofs that are flat or low sloped. PVC or polyvinyl chloride is the third-most widely produced synthetic plastic polymer.
EPDM is an extremely durable synthetic rubber roofing membrane (ethylene propylene diene terpolymer) widely used in low-slope buildings in the United States and worldwide. Its two primary ingredients, ethylene, and propylene, are derived from oil and natural gas.
A metal roof is a roofing system made from metal pieces or tiles characterized by its high resistance, impermeability and longevity. It is a component of the building envelope. Zinc, copper and steel alloys are commonly used.
A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems.