How does the performance of EPDM membrane compare to built-up roofing?

Expansion and contraction, ponding, moisture, thermal shock, and temperature extremes are all factors that promote premature degradation of a roofing membrane. The great elongation and low temperature flexibility of EPDM membrane accommodate building movement in various climatic conditions without stressing the material. Its moisture absorption resistance allows the material to be installed in assemblies with lesser slope than other single-plies and makes it tolerable to incidental ponding and deflection. Unlike built-up roofing, EPDM membrane does not contain organic material that can decay as the result of moisture caused by condensation or leaks. EPDM membrane, due to its ability to withstand extreme temperature, can be successfully used in assemblies with greater thermal resistance (thicker insulations with higher R-values). The ability of a roofing membrane to withstand temperature extremes is an important trait of a high performance material because temperature extremes could ...  more