A metal roofing screw with EPDM washer displayed over a cartoon roof

EPDM Rubber Washers on Metal Roofing Screws

What makes EPDM rubber washers the best option to protect metal roofing screws from leaks, weather, and degradation?

EPDM rubber washers create the watertight seal that protects against leaks around metal roofing screws. Because EPDM resists damage from UV rays, ozone, temperature extremes, and moisture, it lasts significantly longer than other rubber materials in outdoor environments.

Why Roofing Screws Use EPDM Rubber Washers

Unpainted metal roofing screw from the side showing a bonded EPDM rubber washer and hex head

Every roof penetration is a potential leak point, so it's important to use roofing fasteners with strong leak-protection features. High-quality metal roofing screws use a bonded washer consisting of:

  • An EPDM rubber washer
  • A galvanized steel washer

When the screw is tightened, the steel washer compresses the EPDM against the roofing panel, which creates a secure and long-lasting watertight seal that helps prevent leaks.

Because roofing screws are exposed to sun, rain, snow, wind, and temperature fluctuations, the materials must be highly resistant to weathering. That's why EPDM is the best rubber washer for metal roofing screws.

EPDM Compared to Other Rubbers

EPDM rubber is used for its superior resistance to weather and harsh temperatures. Other rubber materials, such as neoprene and natural rubber, break down under exposure to heat, sunlight, and ozone. However, EPDM rubber can be used outdoors for years, if not decades, without degradation.

EPDM Rubber Comparison
Property EPDM Neoprene Natural Rubber
UV Resistance Excellent Moderate Poor
Ozone Resistance Excellent Moderate Poor
Weather Resistance Excellent Good Poor
Temperature Rangne Excellent Good Fair

What is EPDM Rubber?

Metal roofing screws being installed with a power drill

EPDM stands for Ethylene Propylene Diene Monomer, which is a durable synthetic rubber known for its flexibility, weather resistance, and ability to maintain a watertight seal in outdoor environments. It's used in a wide variety of applications, including vehicle seals, weather stripping, pond liners, and roofing.

Advantages of EPDM Rubber

  • Weather Resistance
    • EPDM does not degrade or crack with ozone exposure.
    • EPDM withstands UV radiation without break down.
    • EPDM is stable in hot, cold, wet, and dry environments.
  • Temperature Resistance
    • EPDM rubber washers can withstand temperatures between -60℉ and 350℉.
  • Chemical Resistance
    • EPDM is compatible with harsh stubstances that degrade other rubbers, such as the long-lasting polyurethane paint used on roofing screws.
  • Low Permeability
    • EPDM does not allows liquid to pass through, creating a strong seal.
  • Cost Effectiveness
    • EPDM is relatively inexpensive compared to substitutes such as silicone or thermoplastic elastomer.
  • Environmental Protection
    • EPDM does not degrade in contact with water, so runoff rainwater does not carry rubber pollutants into the environment.

How Long Do EPDM Washers Last?

Dark gray metal roof with standing seams

High-quality EPDM washers can stay serviceable for decades when installed properly on a metal roof. Their resistance to UV light, ozone, moisture, and temperature changes helps them maintain flexibility long after other rubber materials would begin to crack or harden.

However, washer lifespan may vary depending on:

  • Climate conditions
  • Roof exposure
  • Screw quality
  • Installation—Overtightening or undertightening roofing screws can shorten washer life and compromise the seal.

For superior leak protection on a metal roof, use high-quality roofing screws with EPDM rubber washers that resist breakdown from exposure. Always use caution when performing any roofing job, and don't be afraid to reach out if you have hardware questions. Call us at (406)752-5253 or email us at tom@jakesales.com.

FAQ

What is EPDM rubber?

EPDM (Ethylene Propylene Diene Monomer) is a synthetic rubber known for excellent resistance to UV radiation, ozone, moisture, and temperature extremes. It is commonly used in roofing, vehicle seals, weatherstripping, and waterproofing applications.

Why are EPDM washers used on metal roofing screws?

EPDM washers create a watertight seal around the screw penetration while resisting deterioration from sunlight, weather, and temperature changes. This helps prevent roof leaks and extend the life of the fastener.

Are EPDM washers waterproof?

EPDM rubber does not absorb water and creates an effective seal when properly compressed. This makes it ideal for preventing leakage around roofing fasteners.

How long do EPDM roofing screw washers last?

High-quality EPDM washers can last for decades on properly installed metal roofs. Actual lifespan depends on climate, exposure, and installation quality.

Are EPDM washers better than neoprene washers?

For outdoor applications, EPDM generally provides better resistance to UV exposure, ozone, and weathering than neoprene.

Can EPDM washers crack in cold weather?

EPDM remains flexible at very low temperatures and is less likely to crack than many other rubber materials used outdoors.

What happens if a roofing screw fails?

A failed roofing screw can allow water to penetrate the roof, potentially causing leaks, corrosion, and damage to the roof structure if left unresolved. In many cases, roofing fasteners can be easily replaced if they begin to loosen or fail.

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