Roofing system
What is EPDM roofing?
The black rubber roof: a single sheet of synthetic rubber that has covered low-slope buildings for decades and still does.
Updated September 12, 2026 · Every figure links to its source · Sources
DefinitionSystemAlso called: rubber roof, thermoset single-ply
EPDM roofing — a single-ply roof membrane made of ethylene propylene diene terpolymer, a synthetic rubber, supplied in wide sheets and installed fully adhered, mechanically fastened or held down by ballast; the EPDM Roofing Association represents the manufacturers, and the 2021 IRC, Section R905.12 regulates it as thermoset single-ply roofing.
What it is
EPDM is a thermoset: a rubber that has been cured (vulcanised) and cannot be re-melted, which is why its seams are joined with tape or adhesive rather than heat-welded. The sheets are large — wide enough that a small roof can be covered with few or no seams — and are most often black, though white-surfaced sheets exist. On the roof the membrane is either glued to the substrate (fully adhered), fastened through the seams with plates and screws, or laid loose and weighed down with stone ballast or pavers.
The IRC, Section R905.12 sets the rules for houses: a minimum slope of one-quarter unit vertical in twelve horizontal, a material standard (ASTM D4637 for EPDM), and installation per the manufacturer; the IBC, Section 1507.12 does the same for other buildings. The Single Ply Roofing Industry publishes the wind-design and fastening standards the two codes reference.
Why it matters
EPDM has a long record on low-slope roofs — the membrane tolerates ultraviolet light, ozone and temperature swings, stays flexible in cold, and can be patched with the same tape that made its seams. Its weak points are the seams and the details: adhesive seams age, flashings at walls, curbs and drains are hand-made, and a black roof absorbs heat, which matters on an air-conditioned building in a hot climate. The EPA's page on cool roofs explains the reflectance question that has pushed much new work toward white membranes.
The choice a building owner usually faces is EPDM against TPO. Rubber is the older, better-understood material with the simpler repair; TPO is white, heat-welded and reflective. The directory's comparison of TPO and EPDM sets the two side by side.
What it costs and who does it
Single-ply roofing is priced by the square, with the membrane thickness, the attachment method, the insulation beneath, the number of penetrations and the amount of edge and wall flashing as the variables; a tear-off of the old membrane and wet insulation adds to it. Commercial roofing contractors do most EPDM work, and manufacturers train and certify installers whose work they will warrant. The directory's flat-roof replacement cost guide explains how those estimates are put together.
Frequently asked questions
Short answers; the sections above carry the detail and the sources.
How long does an EPDM roof last?
Is EPDM better than TPO?
Can EPDM be installed on a house?
Next step
Find a roofer who does this
Single-ply work is a specialty; ask a contractor which membranes they are certified to install. The directory lists roofing contractors by state and city.
Sources
- EPDM Roofing Association — EPDM Roofing Association (ERA)
- 2021 International Residential Code, Chapter 9: Roof Assemblies — International Code Council (ICC)
- 2021 International Building Code, Chapter 15: Roof Assemblies and Rooftop Structures — International Code Council (ICC)
- Single Ply Roofing Industry — SPRI
- Using cool roofs to reduce heat islands — U.S. Environmental Protection Agency