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EPDM roofing

EPDM (ethylene propylene diene monomer) is a single-ply roof membrane made of cured synthetic rubber, laid in wide sheets on low-slope roofs of offices, warehouses, schools and hospitals. Unlike TPO, a thermoplastic whose seams are heat-welded, EPDM is joined at the seams with primer and tape.

Warranty available
Up to 30 years, depending on thickness and design
Common thicknesses
45, 60, 75 (reinforced) or 90 mil
Seams
Primed and taped; adhesive at some details
Surface
Black as standard; white versions made
Attachment
Adhered, fastened or ballasted

How it's installed

The choice depends on the deck and insulation, the wind uplift the roof has to resist, and whether the structure can carry ballast.

Fully adhered

The sheet is glued to the insulation or a cover board with bonding adhesive, or comes with factory-applied adhesive. Bonded edge to edge, it doesn't billow in wind, and it is the main way white EPDM is installed.

Mechanically attached

Rows of plates and fasteners hold the sheet to the deck, either through reinforced strips the sheet is taped to or through battens set in the seams. Manufacturers make reinforced sheets for this method.

Ballasted

Large sheets are laid loose and held down with stone or pavers, about 10 to 12 lb per sq ft. The structure has to carry that load, and leaks are harder to trace under the stone.

Pros and cons

Where EPDM wins

  • Resists ozone, weathering and heat, and stays flexible in deep cold: the ASTM D4637 standard requires sheets to pass a brittleness test at -49°F.
  • Under ASTM D4637, unreinforced sheet must stretch at least 300% before it breaks, so it can absorb building movement.
  • Sheets come up to 50 feet wide, so large, open roofs need fewer field seams.
  • Ballasted and mechanically attached EPDM can be recycled when the roof is torn off.

Where it falls short

  • Grease and oil attack EPDM, so kitchen exhaust has to be directed away from the roof and oily waste kept off the sheet.
  • Standard black sheet absorbs most sunlight (JM lists 0.06 reflectivity), and Carlisle and Elevate offer their white EPDM mainly for fully adhered roofs.
  • Seams depend on careful lap prep: seam tape needs clean, primed rubber to bond, and splicing below 40°F takes extra heating steps.

EPDM and hail

Hail resistance comes from the whole assembly, not the rubber alone. The usual upgrades are a thicker sheet and a rigid cover board directly under it, and the Defense Department's roofing criteria list fully adhered 90-mil EPDM among roof covers that have performed well with hail up to 2 inches. Fleece-backed EPDM adds a reinforced fleece layer under the rubber; Carlisle offers warranties covering hail up to 4 inches on its 145-mil fleece-backed sheet when fully adhered.

FM Approvals rates complete roof assemblies for hail under FM 4470. Severe Hail (SH) uses a 2-inch steel ball at about 14 ft-lb of impact, while Very Severe Hail (VSH) fires 2-inch ice balls at 53 to 58 ft-lb; FM Data Sheet 1-34 maps the zones where each is expected. Carlisle's VSH-rated EPDM assemblies pair a 90-mil sheet, or a thicker fleece-backed one, with specific cover boards. In hail country, ask for the FM rating of the whole assembly and whether the warranty covers hail.

Compare EPDM

  • TPO vs EPDM
    TPO vs EPDM side by side: welded or taped seams, white or black sheet, roll widths, cold and grease resistance, warranties, and when to pick each.

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Sources

  1. Johns Manville, JM EPDM NR 60 mil Data Sheet (RS-3005)
  2. Elevate (Amrize, formerly Holcim Elevate), RubberGard EPDM brochure
  3. USACE / NAVFAC / AFCEC (via WBDG), UFGS 07 53 23 Ethylene-Propylene-Diene-Monomer Roofing (August 2025)
  4. U.S. Department of Defense (via WBDG), UFC 3-110-03 Roofing, with Change 5 (2020)
  5. Carlisle SynTec Systems, Sure-Seal EPDM Dusted Non-Reinforced Membrane Product Data Sheet
  6. Elevate (Amrize, formerly Holcim Elevate), Elevate Red Shield Warranty Brochure
  7. Carlisle SynTec Systems, Roofing with Resilience: A Review of 30-Year EPDM Enhancements
  8. Carlisle SynTec Systems, SpecTips: New Extended Warranty Options for EPDM
  9. Johns Manville, Bulletin M25-002: Johns Manville Introduces White EPDM
  10. Carlisle SynTec Systems, Sure-White EPDM Membrane Product Data Sheet
  11. Elevate (Amrize, formerly Holcim Elevate), Lowslope Fire Retardant (LSFR) RubberGard EPDM, Technical Information Sheet TIS 103
  12. Elevate (Amrize, formerly Holcim Elevate), Technical Services Bulletin: New 25-Year Warranty Options for RubberGard EPDM Systems
  13. Carlisle SynTec Systems, Sure-Seal EPDM Pressure-Sensitive RUSS Product Data Sheet
  14. Johns Manville, JM EPDM R 75 mil - FIT (MF, 2-Sided) Data Sheet (RS-3103)
  15. Carlisle SynTec Systems, 2" Seam Fastening Plates Product Data Sheet
  16. Elevate (Holcim Elevate UK), What the hail is this? Elevate membranes stand up to hail
  17. Carlisle SynTec Systems, SpecTips: A Single-Ply Solution for Superior Hail and Puncture Performance
  18. Carlisle SynTec Systems, FM's VSH Testing: Very Severe Hail (updated August 2025)
  19. Carlisle SynTec Systems, Carlisle's EPDM Very Severe Hail (VSH) Approved Systems (sell sheet CST-18726)
  20. Carlisle SynTec Systems, Carlisle VSH Compliant Roofing Systems Code Approval Guide (November 2025)

Updated October 2026.