While thermoplastic single-ply membrane roofing like PVC and TPO, thermoset single-ply membrane roofing (EPDM), and modified bitumen “rubber roofing” are some of the most popular roofing systems for new commercial roof installations today, they’re not the only options available. In fact, if you have an aging roof on an existing commercial building, none of these materials may be quite the right—or most cost-effective—fit compared to elastomeric roof coatings.
Capable of stopping leaks, adding energy savings, and revitalizing your current roof without the need for a disruptive total tear-off and reinstallation project, elastomeric coatings are well worth your consideration.
Today’s post introduces coatings with a variety of material properties that can be applied to a wide range of existing commercial roofing systems, including asphalt, metal, and more.
What are Elastomeric Roof Coatings?
In short, elastomeric roof coatings are acrylic or non-acrylic polymer materials that are fluid-applied to a roofing surface. At least, that’s some professional roofers’ official definition.
While everyone is pretty settled on what roof coatings are (sometimes also known as roof sealants), there is actually a bit of disagreement within the roofing industry as to what specific coatings and other materials can be classified as elastomeric.
Generally, the term “elastomeric” applies to any substance with elastic properties, known as elastomers, which can stretch and return to their original dimensions over and over again—not unlike an ordinary rubber band.
However, the overall strength and ways in which certain materials stretch versus others raise arguments among some professionals. Whether a given material is acrylic or non-acrylic is also problematic for some.
To make matters even more confusing, there are some non-coating commercial roof materials, such as most thermoset and thermoplastic single-ply membranes, which are also technically elastomeric. It’s certainly a little bit complicated!
New Installations vs. Restoration Options
In any event, elastomeric roof coatings are almost exclusively used for commercial roof restoration instead of as new installations—with the exception of spray foam polyurethane (SPF). This is because they tend to work best when applied over other roofing materials, including BUR, Mod Bit, and other popular systems, instead of directly to a roof deck or substructure.
Most coatings simply are not thick enough to stand on their own, but they can enhance the properties of existing roofing for better energy efficiency and seal out leaks—sometimes as well as a brand new roof.
Common Types of Elastomeric Roof Coating Materials
While there are many different chemicals that can make up a given elastomeric roof coating, these particular polymers provide the best performance for commercial roofing applications.
Butyl Coatings
Butyl polymers are solvent-based synthetic rubber materials with excellent elongation and tensile strength properties. Butyl is non-acrylic, which throws its definition as an elastomer into question for some roofing industry professionals who only call acrylics elastomeric.
The benefits of butyl coatings include excellent reflectivity against UV light (aka the sun’s rays) and exceptional performance as a vapor barrier. For businesses where strong vapor retardant barriers are critically important, such as commercial cold storage facilities, butyl coatings applied over another roofing material like SPF often perform quite well.
Polyurethane Coatings
As mentioned above, polyurethane might be either a coating or an original roof material, depending on its application. Polyurethane is incredibly durable and can offer some added insulation value to your roof. It’s not as reflective as other elastomeric coating options, but it does perhaps stand up to ponding water a bit better than silicone and acrylic materials.
Silicone Coatings
Silicone as a material has long been used as a sealant in many industries to fill gaps between other materials. Think of the caulk around the shower in your bathroom—that’s likely made of silicone. This polymer is made to stretch without breaking—called elongation—to the tune of about 200-250%.
Silicone roof coatings are highly reflective and can offer building owners and managers significant energy savings. The material is often a good option for metal roofing restoration (though butyl may be better) due to its ability to protect against rust and material corrosion.
Acrylic Coatings
Acrylic materials were actually some of the first used in roof coatings, and this is why some commercial roofers may still refer only to acrylic coatings as elastomeric, barring all other types.
While acrylic coatings are durable, they have been falling out of favor in commercial roof restoration as scientific advances have made alternative materials in the market more convenient. Acrylic roof coatings usually require a primer, fabric reinforcement, and two coats of the material itself to offer the same level of protection as other options. For instance, silicone roof coatings can often be applied in a single coat for even better potential longevity.
Choosing the Best Coating for Your Commercial Building
There are many factors that should go into your decision-making process about whether to restore your commercial building’s roof rather than pursue a replacement project. As with determining the best original roofing material for your commercial building, considerations regarding everything from local weather conditions/climate to what type of business you conduct in your building cannot be ignored.
In the end, choosing the best elastomeric roof coating for your commercial building is a job best left to the experts, like our skilled craftsmen here at Heidler Roofing. When you work with experienced roof restoration professionals, we coordinate with you on all of your business’s needs, including your overall budget, to find the best commercial roofing option for you.
For commercial building owners and managers in the Mid-Atlantic region, Heidler Roofing is your best resource for commercial roof preventative maintenance, roof restoration, and more. Get in touch today to experience our legendary service for yourself.