Long Term Performance

The long-term weathering study completed recently shows that 30-Year roofs continue to perform well.

  • All samples were performing like new—after up to three decades in the field.
  • EPDM withstands the effects of various climates extremely well.
  • Properly designed, installed, and maintained EPDM systems can successfully withstand extreme weather cycles.
  • Indications that EPDM systems can approach or exceed 40 years of service life.

This state-of-the-art study of roof systems provides tangible proof of the long-term performance capability of EPDM. The study examined five roof systems, ranging from 28 to 32 years of in-field service, and concluded that all of the systems examined were still performing as intended. In fact, the study found that all of the samples were essentially performing “like new” with physical characteristic properties above or just below the minimum characteristics of newly manufactured 45-mil EPDM membrane. The roofs were first inspected in the field to get a good sense of their condition, and then samples were sent to Momentum Technologies, a testing facility for the roofing industry. The laboratory testing examined five critical performance characteristics of the EPDM membrane.

The Elongation Test Results showed that four of the five roof samples exceeded the minimum characteristics for aged EPDM, and one exceeded the minimum for new EPDM. For Tensile Strength, all five samples exceeded the minimum standard. For Thickness XD, three samples exceeded the manufacturer minimum, while the other two missed by one-thousandth of an inch. For Thickness MD, three achieved or exceeded the minimum, while one missed by one one-thousandth of an inch and another by four one-thousandths of an inch. For Factory Seam Strength (Figure 5), it was only possible to test two of the samples and both easily surpassed manufacturers’ minimums.

This is the fourth study conducted on EPDM that supports the long-term performance of the EPDM membrane. “The first field studies of EPDM were done in the late 1980s, and we are finding a pattern,” says Thomas W. Hutchinson AIA, FRCI, RRC and Principal, Hutchinson Design Group, Ltd., Barrington, Ill. “The pattern is that these roofs can really last a long time. By using today’s advanced design techniques and proper roof maintenance, it is reasonable to expect that an EPDM roof will approach or exceed 40 years of service.”