Roofing Dilemma: To Coat or Not to Coat?

August 25, 2022

Coating your roof can be a great way to postpone the high-cost of tear-off, disposal, and replacement.

A coating project can cost 25-percent less than reroofing. In addition to a lower initial cost, the project may also qualify for rebates from your local utility company or a government-sponsored energy rebate program. Before you commit to the idea, you have to find out if roof coating is even possible.

How to Know if the Roof can be Coated

Metal roofs, single-ply systems, modified bitumen, and built-up asphalt roofing can all be coated, as can spray polyurethane foam installations. The ideal time to apply roof coating is before the existing roof system starts to show deterioration.

You cannot apply coating to a roof that has:

Additionally, roofs with poor drainage are not a candidate for coating application. The coating deteriorates faster because of the presence of ponding water. Water dispersion or drainage systems must be added before coating.

Infrared imaging or core cuts may be used to identify the presence of moisture. Once wet areas are replaced and repaired, an adhesion test is conducted to make sure the coating will bond properly. All repairs or corrective actions should be made prior to the coating application. Only then can the project begin.

The Benefits of Roof Coating

While coating can conceal evidence of rust on metal and improve the overall appearance of the roof, aesthetics isn’t typically the motivation for a coating project. The two best reasons to coat your roof are for energy savings and increased roof life.

Applying a reflective coating to your roof can reduce the building temperature and how hard air-conditioning equipment must work to cool the interior. According to the United States Environmental Protection Agency (EPA), “A high solar reflectance – or albedo – is the most important characteristic of a cool roof as it helps to reflect sunlight and heat away from a building, reducing roof temperatures. A high thermal emittance also plays a role, particularly in climates that are warm and sunny. Together, these properties help roofs to absorb less heat and stay up to 50-60 degrees F (28-33 degrees C) cooler than conventional materials during peak summer weather.”

The Cool Roof Calculator from the U.S. Department of Energy’s Oak Ridge National Laboratory may help estimate energy savings. Because cool roofs in northern climates can cause an increase in heating demand during cold winters, it’s important to work with a professional, though, to evaluate whether a reflective roof is right for your facility.

Not only can these coatings offer you greater reflectivity, but they can also extend roof life. Ultraviolet and heat exposure cause chemical degradation of the roof membrane. Likewise, water accelerates deterioration. Coating can slow this process by providing an extra layer of protection to the surface of the roof.

Roof coating prolongs the life of an existing roof system too, increasing time between reroofing projects. By preventing moisture, chemical, or physical damage, roof coatings can help reduce the amount of maintenance required. Additionally, because coating is considered a maintenance expense, it’s tax deductible.

All coating manufacturers offer warranties (either material only or labor and materials,) for between five and 25 years. If the original roofing system remains in good condition, recoating again is possible. Even recovering the roof system is feasible since coating systems are not considered a roof (most building codes prohibit recover when there is more than one existing roof system left in place due to load concerns).


Wondering if your roof can be coated? Contact D. C. Taylor Co. at 319.731.4118.

Contact Us Today To Get Started On A Quote