A TPO roofing membrane is made from ethylene propylene rubber. Special technology is used to chemically bind together, rubber, ethylene (an organic gaseous substance) and propylene (a byproduct of petroleum refining). At the end, numerous filler materials are added, such as talc, carbon filler and fiberglass. These fillers reinforce the TPO membrane’s strength and durability. A TPO roofing membrane has been specifically designed to have the advantages of a rubber roof, combined with hot – air weldable seams for extra durability. TPO roofing membranes have been manufactured in the US since the early 1990’s and are now the fastest growing segment of the US single-ply roofing industry.