Closed-Cell EPDM Foam

Closed-cell EPDM foam delivers excellent weather, ozone, and hot-water resistance at a lower cost than neoprene sponge. We stock EPDM sponge in sheet, roll, and strip form for outdoor weather sealing, roofing gaskets, and potable water applications where UV and ozone exposure are the primary concerns.

At a Glance

Temperature Range

-40 °C to +100 °C continuous (sulphur-cured); -50 °C to +110 °C continuous (peroxide-cured)

Thickness Range

1.5 mm to 50 mm

Available Forms

SheetRollStripDie-cut gasketAdhesive-backed

Colours

Black (standard)
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Technical Properties

Typical values across stocked grades. Specific grade data sheets available on request.

Cell StructureClosed-cell, moisture and vapour resistant
Temperature Range-40 °C to +100 °C continuous (sulphur-cured); -50 °C to +110 °C continuous (peroxide-cured); intermittent peak +130 °C
Density (ASTM D1056)80–320 kg/m³ (grade dependent)
Compression Set (ASTM D1056)15–35% (25% deflection, 22 h @ 70 °C)
Compression Deflection (ASTM D1056)35–240 kPa (grade dependent)
Tensile Strength (ASTM D3574 / D1056 cellular section)0.4–2.0 MPa (cellular test method; ASTM D412 dies are for solid rubber and produce non-comparable data on sponge)
Elongation at Break100–250%
Water Absorption (ASTM D1056)<3% by volume
Ozone ResistanceExcellent (inherent EPDM resistance)
UV ResistanceExcellent. Black grades suited to permanent outdoor exposure
ColourBlack (standard)
Thickness Range1.5 mm to 50 mm

Physical Characteristics

Density

80–320 kg/m³ (grade dependent)

Tensile Strength

0.4–2.0 MPa

Chemical Resistance

Resistant To

  • Water and hot water — to 100 °C continuous (sulphur-cured) or 110 °C continuous (peroxide-cured); above 100 °C requires pressurised system, so verify gauge pressure before specifying
  • Ozone and UV radiation (permanent outdoor exposure)
  • Dilute acids and alkalis
  • Potable water systems (AS/NZS 4020:2018 Amd 1:2022 compliant grades available)
  • Automotive coolant and antifreeze
  • Alcohols (ethanol, isopropanol; moderate resistance)

Limited Resistance

  • Vegetable oils and animal fats
  • Dilute mineral acids at elevated temperature
  • Ketones (MEK, acetone) cause moderate swelling in some compounds

Not Recommended

  • Mineral oils, petroleum fuels, and hydrocarbon solvents (EPDM swells and degrades; use neoprene or nitrile sponge instead)
  • Aromatic solvents (toluene, xylene); rapid swelling
  • Chlorinated solvents, which cause polymer breakdown
  • Concentrated strong acids attack the EPDM backbone

Environmental Ratings

Weather Resistance

Excellent, and well-suited to outdoor and rooftop applications

Ozone Resistance

Excellent. Inherent resistance, with no antiozonant additives required

UV Resistance

Excellent. Black grades resist UV degradation for 10+ years of outdoor exposure

Standards & Certifications

Standards Compliance

ASTM D1056 (flexible cellular rubber, sponge and expanded; Type 2 Class A non-oil-resistant grades 2A1–2A5 typical for EPDM)ASTM D3574 (flexible cellular materials — slab, bonded, and moulded foams: tensile, tear, density)AS/NZS 4020:2018 Amd 1:2022 (products in contact with drinking water; compliant grades available)

Common Applications

  • Roofing and skylight gaskets
  • Solar panel mounting gaskets
  • Outdoor electrical enclosure seals
  • Potable water system gaskets (AS/NZS 4020 grades)
  • HVAC duct seals and weather stripping
  • Agricultural equipment weather seals
  • Window and door frame gaskets
  • Expansion joint fillers

Not Recommended For

  • Not oil-resistant. EPDM sponge swells in petroleum oils, fuels, and hydrocarbon solvents, so use neoprene or nitrile sponge for oil exposure.
  • Limited flame resistance: EPDM sponge burns if ignited. For fire-rated applications use silicone or neoprene sponge.
  • Compression set increases above 90 °C, so derate for sustained hot-service applications
  • Lower mechanical strength than solid EPDM rubber. Sponge is for sealing and cushioning, not structural loads
  • Black colour only in standard grades. Coloured grades are available on request with longer lead times

Available Grades

EPDM Sponge, Medium Density (ASTM D1056 2A2 / 2A3)

Our go-to closed-cell EPDM at 100–160 kg/m³, classified ASTM D1056 Type 2 Class A (non-oil-resistant) Grade 2 or 3. Handles rooftop gaskets, outdoor enclosures, and environmental sealing — anywhere UV and ozone exposure are the main threats.

EPDM Sponge, High Density (ASTM D1056 2A4 / 2A5)

Firmer grade at 200–320 kg/m³, classified ASTM D1056 Type 2 Class A Grade 4 or 5. Used for higher bolt loads, vibration isolation, and applications requiring minimal compression under sustained load.

EPDM Sponge, Adhesive-Backed

EPDM sponge with pressure-sensitive adhesive on one side. Saves time on vertical and overhead surfaces where mechanical fixing isn't practical.

EPDM Sponge, Potable Water Grade

Closed-cell EPDM formulated and tested for compliance with AS/NZS 4020 (products in contact with drinking water). Suited to potable water system gaskets.

Need Closed-Cell EPDM Foam?

We supply closed-cell epdm foam in sheet, roll, and custom die-cut forms. Contact our team for pricing, data sheets, or technical assistance.

Disclaimer

This resource is provided for general engineering reference only and does not constitute professional advice, specification, or guarantee of performance. Actual results depend on specific application conditions. Universal Gaskets Pty Ltd accepts no responsibility or liability for decisions made based on this information. For full terms, see our Terms & Conditions.