EPDM roofing is a popular choice for flat and low-slope roofs. EPDM stands for ethylene propylene diene monomer and the membrane is a durable synthetic rubber designed to resist weather, temperature changes, and UV exposure. It is known for dimensional stability and resistance to ozone and weathering. Used on residential, commercial, and industrial buildings, EPDM roofing offers a long service life with relatively straightforward installation and maintenance.
What is EPDM roofing?
EPDM is a synthetic rubber membrane formed from ethylene propylene diene monomer. It's supplied in large sheets or rolls that are cut to fit roof areas. Membrane thickness is usually measured in mils, commonly 45 to 90 mils, with 60 mil variants widely used. It can be black or white; white variants are reflective and help reduce cooling costs in sunny climates. The installation methods include fully adhered sheets, mechanically attached membranes, or ballasted systems using ballast such as rocks. Quality EPDM joints are sealed with seam tape or liquid adhesives, and flashing details around penetrations and edges are critical for water tightness.
Benefits of EPDM roofing
- Durability and flexibility to accommodate building movement
- Excellent impermeability to water when seams are properly sealed
- Low maintenance compared to some other flat roof options
- Energy options including white EPDM that reflect sunlight
- Cost effectiveness and ease of field repair
Types and installation
Sheet membranes come in large rolls and are sized for your roof. The most common installation methods are fully adhered where the membrane is glued to the roof deck and sealed at the seams, mechanically attached where fasteners secure the membrane with or without a ballast layer, and ballasted systems that use weight to hold the membrane in place. Adhesives cure during installation and require proper weather conditions. Flashing at valleys, edges, vents, and penetrations should be installed by a skilled professional to prevent leaks. In energy mindful projects, white EPDM is used to reflect solar heat, while black EPDM remains a cost effective option for many climates. Thickness options range from 45 to 90 mils; thicker membranes provide greater longevity and resistance to punctures in harsh climates.
Maintenance and longevity
EPDM roofs often deliver long service life, typically 30 to 50 years with proper care. Routine maintenance includes keeping gutters clear, removing debris, inspecting seams for signs of wear, and ensuring ponding water is minimized. Periodic inspections every 3 to 5 years by a qualified roofer can catch flashing issues, seam wear, or membrane damage early. When minor leaks occur, professionals can reseal seams or replace damaged sections without a full roof replacement. Warranty terms vary by product and installer, commonly ranging from 10 to 20 years, with more robust warranties available from top manufacturers.
Cost considerations
Costs vary by roof size, complexity, primer and adhesive choices, and labor rates. A typical installed price range is four to eight dollars per square foot for standard EPDM, with white reflective membranes sometimes priced higher due to material costs. If a roof requires tear off or extensive flashing work, the total can be higher. It is important to factor in long term energy savings on white EPDM as a potential offset. Always obtain multiple bids and verify that bids include removal of old roofing, disposal, flashing, and warranty coverage. A professional assessment helps determine the best installation method and membrane thickness for the climate and roof design.
EPDM vs other roofing options
| Aspect | EPDM | TPO | PVC | Asphalt |
|---|---|---|---|---|
| Durability | Very good in weathering and flexibility | Good | Excellent | Moderate |
| Cost | Low to mid | Mid | High | Low |
| Maintenance | Low | Low | Low | Moderate |
| Energy performance | Neutral to good | Good | Excellent if white | Moderate |
Considerations for choosing EPDM
When selecting an EPDM system, work with a licensed roofing professional who has hands on experience with EPDM installations. Check warranty terms and whether the system is fully adhered or mechanically attached. Confirm flashing details around skylights, vents, HVAC curbs, and roof penetrations. Consider climate, expected movement of the structure, and roof design to select the appropriate thickness and installation method. You can improve long term performance by ensuring proper drainage and periodic inspections as part of a proactive maintenance plan.
Conclusion, EPDM roofing offers a durable and cost effective solution for flat roof systems. With the right membrane type, expert installation, and ongoing maintenance, you can expect decades of watertight performance and solid value for your building.
