The EPDM (ethylene propylene diene terpolymer) single-ply rubber roofing membrane has been the most popular choice of the commercial roofing industry for over 40 years. One of the reason is because EPDM is relatively inexpensive. EPDM is a rubber material whose principal components consist of the compounds ethylene and propylene. The low-cost types of EPDM used on many commercial roofs offer many pitfalls for inexperienced installers. These EPDM roofing sheets shrink significantly as they age, creating stress at walls and edges that will tear the sheets and shorten their lives. EPDM also is a very inefficient roofing system, and in todays economy many business owners are looking to reduce costs.
Many business owners only want to install EPDM, but many commercial roofing professionals believe that TPO membranes are the superior roofing system. Replacement of EPDM to TPO is becoming a popular trend in the commercial roofing industry.