Today’s blog post looks at the performance value of single-ply EPDM rubber roofing and how, in some situations, it may be enhanced with a compatible commercial roof coating membrane system. We start by reviewing a few basic facts about EPDM rubber roofing and then take a look at how a reflective, white roof coating may add further value when the existing roof is suitable for restoration.
A Few Basics about EPDM Rubber Roofing
Ethylene propylene diene monomer roofing, or simply EPDM rubber roofing, has been used in commercial roofing for decades. It is a single-ply membrane system commonly used on low-slope commercial buildings.
EPDM rubber roofing is available in different colors and configurations, although dark-colored membranes are common.
Like other commercial roofing systems, EPDM can provide long service when it is properly designed, installed, inspected, and maintained. Over time, however, seams, penetrations, flashing, surface damage, drainage issues, and other conditions may need attention.
Commercial Roof Coatings Can Enhance a Suitable EPDM Roof
A compatible roof coating system may provide additional protection and reflective performance when an existing EPDM roof is structurally sound and otherwise suitable for restoration. Here are a few areas where a coating system may provide benefits.
- Punctures and surface damage — EPDM membranes can be durable, but they can still be damaged by sharp objects, foot traffic, hail, equipment, or other impacts. A compatible coating can provide an additional protective surface over properly prepared areas, but damaged membrane should still be repaired before coating.
- Seams — Many EPDM roofs contain seams that require proper detailing and maintenance. Over time, seams or related flashing may become vulnerable to water intrusion if they deteriorate or are damaged. A coating system may provide a continuous protective surface over properly prepared and repaired areas, while seams and other vulnerable locations may require additional reinforcement or detailing.
- Sun exposure — EPDM roofing and its accessories are exposed to temperature changes and ultraviolet radiation throughout their service life. Some elastomeric coatings are designed to accommodate movement while also reducing solar heat absorption when they have a reflective surface.
- Curbs and rooftop units — Penetrations, curbs, HVAC equipment, flashing transitions, and other roof details are common areas where leaks can develop if materials deteriorate or detailing fails. These areas should be carefully inspected and repaired as needed before or during a coating restoration project.
- Roof surface — Dark EPDM surfaces can absorb substantial solar heat. Applying a compatible white or reflective coating may reduce roof surface temperatures and lower the amount of solar heat absorbed by the roof. Depending on the climate, insulation, HVAC system, building use, and other factors, this may also contribute to lower cooling demand and energy savings.
Determining Whether an EPDM Roof Is Suitable for Coating
A roof coating membrane system can be a useful restoration option, but it is not appropriate for every EPDM roof.
Before coating, the roof should be evaluated for wet insulation, structural deterioration, drainage problems, widespread membrane damage, failed seams or penetrations, trapped moisture, and other conditions that may need to be corrected first.
Compatibility is especially important with EPDM. The selected coating, primers, repair materials, and preparation procedures should be suitable for the existing membrane and installed according to current manufacturer requirements.
When the roof is a suitable candidate, a reflective coating system may provide benefits such as:
- A continuous protective surface over properly prepared roof areas
- Reduced solar heat absorption
- Lower roof surface temperatures
- Potential reductions in cooling demand
- Reduced tear-off and disposal compared with full replacement when restoration is appropriate
- Potential extension of the existing roof’s useful life
- Repair and recoating options for some systems when conditions allow
Performance characteristics such as reflectivity, elongation, tensile strength, weather resistance, warranty terms, maintenance requirements, and expected service life vary by product and system. These should be evaluated using current manufacturer documentation and the conditions of the specific project.
A commercial roofing contractor can inspect the existing EPDM roof and discuss whether repair, restoration, coating, recover, or replacement is appropriate.
