What is EPDM? And “Why EPDM Rubber on Commercial Roofs?”
This article and others on this website along with videos will prove that it is not wise to install EPDM Rubber on Commercial Roofs
EPDM comes from its inclusion of Ethylene, Propylene, Diene Monomer. EPDM is an elastomeric compound, which consists of oil-based by-products and other compositions of modifiers and stabilizers.
It was during the late 1960s that using EPDM rubber roofing as a roofing material. This formulation replaced the more labor-intensive, Built-Up-Roofing (BUR) also known as Hot-Tar-and-Gravel Roofing.
EPDM Rubber on Commercial Roofs
The question is “Why anyone would think to install EPDM Rubber on Commercial Roofs” This and other articles will paint a clearer picture as to why EPDM Rubber on Commercial Roofs is not a wise decision.
The video below shows EPDM leaks due to adhesives failing to maintain bonding properties. Notice the ease he is removing the rubber cover tape on the edge of the roof.
Thin EPDM Membranes on Commercial Flat Roofs
EPDM membranes are available in three thicknesses: 45 mil., 60 mil., and 90 mils. (mils. refers to .001 or a thousandth of an inch). A membrane that’s 60 mils, would be 1/16th of an inch thick, and about equal to the thickness of a quarter.
Most roofing contractors will install the 45 mils. Membrane unbeknownst to their clients, however, a 45 mil. The membrane is too thin and susceptible to tears and punctures.
Ultraviolet/Climate Degradation of EPDM
Regardless of its popularity, EPDM has a set of drawbacks as a roofing system. Field tests over four generations have shown that no matter the thickness installed, the black color of the EPDM absorbs harmful UV rays. The UV’s cause adhesives to fail and the rubber to become brittle over time, providing only a 15-year period of protection.
EPDM Adhesives Fail
When fastening EPDM rubber membrane to a substrate, like plywood or insulation board, is by applying adhesives with a paint roller. Using EPDM adhesives to flash rooftop units, such as skylights, vents, drains, a/c units, extractor fans, stovepipes, and chimneys.
These adhesives fail to maintain their bonding properties due to harmful UV rays. Adhesives are such an integral component of the entire roof system, yet, have failed time and again, even though new formulations have been introduced five times since the early 1970s. To date, there are no proven remedies.
Traffic on EPDM Flat Roofs
It is inevitable that flat roofs will have foot traffic for snow removal and from maintenance workers servicing air conditioners, vents, skylights and the like. Snow shovels can pierce the EPDM rubber and create gouges and gashes which may become leaks.
Also, service workers drop and unintentionally leave behind screws, nails, and other sharp objects. When someone steps on these sharp objects, they will pierce the membrane and eventually cause leaks.
EPDM is not a Viable Commercial Roofing System
Many roofers believe in the overall practicality of an EPDM single-ply roof, but faulty installations and materials’ failures have resulted in damage causing the need for long-term, intermittent repairs.