Elastomeric Coating 101

An elastomeric coating is a coating that’s capable of being stretched at least twice its original length (100% elongation) and recovering to its original dimensions.

Elastomerics are used in commercial roofing as a liquid that gets applied on top of an existing roofing systems to form a membrane. They also make the roof:

  • waterproof
  • a monolithic layer
  • cooler by adding an element of reflectivity from the sun
  • have an extended life
  • have a 10-20-year warranty

Usually, an elastomeric roof coating comes in white to add reflectivity, but in some territories a grey color can be used to absorb heat during the winter months.


The three most popular types of elastomeric coatings are acrylic, silicone and urethane.

Acrylic – water-based coating that’s only applied to roofs with a slope. If an acrylic roof has standing water (meaning the water just sits there and does not run off the roof), the standing water will cause the reversion of the coating back to a fluid and eventually wash right off your roof.

Acrylics are typically 52% solids by volume and 48% water (or other type of carrier), so when it’s applied, almost half of the product is lost through evaporation. Although cheaper than other elastomeric coatings, you’ll need to apply much more product to account for what’s lost during evaporation.

Silicone – is a silicone resin-based coating that’s 96% solids/4% carrier. Which means 96% of what goes down on your roof will stay on your roof. Silicones perform great on flat roofs because they can withstand ponding water. Silicones are a middle-of-the-road coating in terms of performance and price.

Silicones are twice as resistant to weathering than acrylics, but also more expensive.

Urethane – urethanes have the most impact resistance of any elastomeric roof coating available. However, urethanes are very expensive compared to the other two and do not hold up to standing water very well.

Superior Seamless Roofing

At Superior Seamless Roofing, we stand behind the very best commercial roofing systems, which is why we recommend ASTEC roofs to our commercial clients. As the only contractors in all of Connecticut authorized to install ASTEC roofing systems, we’re dedicated to equipping the United States with the best in commercial roofing as commercial roofing contractors.

Once you know the kind of roof coating you need for your application, you’ll want to find a brand or manufacturer that supplies quality roof coatings that provide your desired results. Our Expandothane  is another product we recommend produced by Dow Chemical offers high corrosion resistance, hail resistance, excellent physical properties, and waterproofs your roof. Contact the experienced team at Superior Seamless Roofing if you are considering waterproofing your roof. We’ll make honest recommendations that fit your buildings needs.

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