EPDM, or ethylene propylene diene terpolymer, is a synthetic rubber that is used in modern green roofing projects. EPDM is derived from a combination of oil and natural gas to produce a, durable, versatile and flexible roofing system that can be used in a wide range of temperatures. Because of its unique formulation and its simple set-up process, EPDM is the only roofing system that is recommended for use in water collection.
There are several major benefits that go with using EPDM on your roof. These include, but are not limited to the following.
- Proven, time-tested system
- Flexible, expands and contracts
- Easy to repair
- Weather resistant
- Proven hail resistance
- Superior resistance to extreme heat and fire
- Thermal shock durability
- Ultraviolet radiation resistance
- High resistance to ozone, weathering and abrasion
Although EPDM is a highly effective, convenient and durable material, it does not have the solar reflective qualities of TPO. For that reason, EPDM is generally recommended for use in more northern climate zones, where the temperature is seasonably cooler than areas farther south. If you already have an EPDM ballasted roofing system, however, EPDM may be an appropriate solution for you.
There are several methods for installing EPDM on your roof. The material is supplied in large rolls of varying size and thickness and can be directly adhered, mechanically fastened, or ballasted to your roof. The latter is the more economical method for large projects involving structures that can support the rock ballast’s weight. Sheets are sealed together to form a waterproof bond using seam tape, which are treated with adhesive, meaning they will eventually require maintenance, or in extreme cases, replacement.
When it comes time for maintenance repairs, the installed membrane is first thoroughly cleaned and primed to allow for maximum adhesion. Cuts or punctures in the material are repaired with an adhesive backed EPDM patch. Once this patch is in place, sealant is applied around the edges and left to dry to ensure that the repair lasts for the lifetime of the roof.