how do silicone roof coatings work

How To Save Money and Extend the Life of Your Commercial EPDM Roof?

Greg PalyaSilicone Roof Coatings, Spray Polyurethane Foam Roofing

Summary: You can make minor repairs (if needed) and install spray polyurethane foam over your existing EPDM roof. Or, if your roof is in good enough condition, you can install a roof coating system over what you already have. Either way will minimize tear-off (huge cost savings versus ripping everything off) and it will get you a new 10-20-year warranty. The roof system will also be renewable, which means you won’t need to remove it once the 10-20-year warranty expires.

I know that was a long “summary”, but there’s really no shorter way to explain it.

In this article, you’ll learn:

  • What is an EPDM roof?
  • Why spray foam is a good option to extend the life of an EPDM roof?
  • What potential problems could happen with spray foam?
  • Why roof coating systems are cost-effective for EPDM restoration?
  • What problems can happen if you go with a roof coating system?

I wanted to point out that we only write articles based on true events and experiences. West Roofing Systems has been in spray foam roofing since 1979. Every piece of content written is produced in-house. And every article is reviewed and edited by a roofer/salesman with 30+ years of experience in the field.

Let’s get started!

What is an EPDM roof?

EPDM stands for Ethylene Propylene Diene Monomer. It’s a single-ply membrane that consists of a synthetic rubber compound that allows it to be flexible. 

EPDM usually comes in 45, 60, or 90 mils thickness and is either black or white.

EPDM is rolled out into strips and is fastened to the roof’s insulation through fasteners or with an adhesive.

City of Lorain - EPDM Installation
EPDM roof installation at the City of Lorain

Now that you know if you do (or don’t) have an EPDM roof, let’s get into spray foam and why it’s a cost-effective option.

Why is spray foam a good option to extend the life of an EPDM roof?

Spray polyurethane foam is a great option because it’s easy to install and it’s installed over your existing roof.

The roof is cleaned through power washing and then a coverboard is installed.

A coverboard is needed to give spray foam a sound, full-adhered substrate to adhere to.

Then it’s time to start spraying foam!

If you wanted to install a new EPDM roof and get a warranty, you would need to remove the entire roof, pay to transport all the materials to a landfill, and then install all new materials.

Spray foam has other benefits that other roofing systems don’t have, such as:

  • Spray foam leaves behind a seamless membrane. Seams are the most common area where roofs fail.
  • Spray foam has an R-value of 6.5 per inch of thickness. This can greatly reduce your energy bills and extend the life of your HVAC equipment.
  • Spray foam is renewable. When the warranty expires, a contractor can clean the roof and install more protective coating. A “recoat” costs ½ to 1/3 of the original installation. Other roofing systems are not renewable and need to be torn off, costing 100% of the original installation.
  • Spray foam is closed-cell. This means that even if a puncture occurs, the water will sit in that hole and not move. Other popular insulations will absorb the water and allow it to travel, causing leaks and a large area of the insulation to be wet.

Now that we know the “good” about spray foam, what potential problems can happen?

What potential problems could happen with spray foam?

There are a few problems that can happen when choosing spray foam:

  • If there are two roofing systems already installed, you legally need to remove at least one roof system before installing spray foam.
  • Spray foam may appear easy to install because it’s fluid-applied, but there is A LOT of science involved in spraying good foam. You need to be very careful that the contractor knows what they are doing. Here are some tips for choosing a good spray foam roofing contractor.
  • Since spray foam is “sprayed”, overspray can occur. Overspray is when the foam is taken by the wind and landing on undesirable assets, such as cars, windows, etc. A good spray foam contractor knows how to work with the wind, spray out of a booth, use windscreens, and/or cover cars. Overspray is a problem spray foam has that other roofing systems don’t have.

Now that we know about spray foam, what about roof coating systems?

Why roof coating systems are cost-effective for EPDM restoration?

Roof coating systems are great for EPDM restorations because they are installed right over the top of what you already have.

EPDM roof renewed with silicone coating
roof coating system over an existing EPDM

To install a roof coating system correctly and get a manufacturer’s warranty, a roofing contractor will prepare the roof, then simply spray or roll the coating onto the roof.

Coating systems are cost-effective because:

  • Tear-off is minimized
  • If your EPDM roof is dark in color, you can install a lighter colored coating to reduce roof temperature (saves on energy bills)
  • Coating systems are renewable. Once the warranty expires, a contractor will prepare the roof, then install more protective coating.
  • Coating systems are considered roof maintenance (and not a roofing system), which means that you can install a roof coating system even if you already have two roofing systems installed. No other “roofing system” has this advantage.

What problems can happen if you go with a roof coating system?

There are a few problems that can happen when choosing a roof coating system:

  • A roof needs to be in good condition or else it won’t be eligible for an install. Good condition means that the seams are still intact, less than 25% of the roof’s insulation is wet, and there’s been some sort of annual maintenance on the roof.
  • Roof coating systems do not provide any insulation or R-value.
  • Many building owners choose white or light gray to maximize the reduction in roof temperature, but these colors will appear dingy when exposed to the elements over time. This doesn’t affect performance.


Hopefully, after reading this article, you have a better understanding of the options you have to restore your EPDM roof.

Most EPDM roof owners think that the only option they have is to rip it all off and install a new one.

But why would you pay for all the labor for a tear-off if it can be avoided (or at least minimized)?

Since 1979, West Roofing Systems has been coming up with the most cost-effective solutions to commercial roofing problems. Sometimes spray foam is the best option, sometimes it’s best to perform a tear-off and start over.

But the best thing is to request a quote and get a professional on your roof. They will pull core samples, do a visual inspection, and justify their reasons for the repair/restoration options they recommend.

If you’d like to learn more about spray foam or roof coating systems, please download the “Cheat Sheets” below.

The spray foam roofing cheat sheet - download now download the silicone roof coating cheat sheet
About the Author

Greg Palya

Greg Palya is the Digital Content Manager of West Roofing Systems, Inc. He has a B.S. in Marketing from the University of Akron and an MBA in Marketing from Walsh University. When he's not trying to teach others about spray foam roofing and silicone roof coatings, you can find him on the basketball court or golf course.