Elastomeric coatings are not “one-size-fits-all.” There are many varieties and formulas, and each lends itself to different environments and surfaces. The four common types of elastomeric coatings are butyl, acrylic, polyurethane, and silicone.
Butyl is created with isobutylene, which is refined into butyl rubber before being made into a liquid for elastomeric coatings. Butyl rubber is impermeable to air, boasts excellent flexibility, and can even withstand ponding on low-slope roofs. However, the creation and disposal of butyl are harsh on the environment, so some contractors prefer to use other types of elastomeric coatings.
Acrylic elastomeric coatings, like our product: AC58, are highly durable and better used on roofs with better drainage, as they do not withstand ponding as well as other types of elastomeric coating. Acrylic coatings have a high amount of solids and are more reflective than their counterparts, making them a better choice for extreme UV climates. Many acrylic coatings also include potent biocides that deter mildew and mold growth.
Polyurethane, or urethane, coatings are incredibly durable compared to the other elastomeric coatings. This durability lends itself well to roofs with higher-than-average foot traffic, and also means that these coatings remain tough against ponding. Plus, polyurethane coatings can withstand the expansion and contraction of roofs as the temperature changes. The only warning for polyurethane coating is that it does not play well with DIYers; since these coatings are xylene-based, they are harsh on installation equipment and can be difficult to spray.
Silicone coatings, including our product: SI92, boast a solids percentage of nearly 90%, if not higher, meaning that contractors use less material to achieve the desired thickness. This high solids content also allows silicone elastomeric coatings to be highly UV resistant and withstand ponding. Silicone coatings also erode at a much slower rate than other elastomeric coatings, meaning they last longer. The downside? Silicone coatings demand the most maintenance, as they attract dirt easily and will lose reflectivity if not washed periodically. The silicone coating can also be very slippery when wet and is prone to tearing (but adding roofing granules into your system can solve this problem.)