What are Acrylic Roof Coatings?
Acrylic coatings are made from similar materials as paint, caulk, adhesives, and even plexiglass. While plexiglass is a pure acrylic compound, most polymers are blended with other materials to give them different properties such as flexibility, adhesion, high and low temperature performance, and elasticity.
Uses of Acrylic Coatings
The acrylic coatings we’re concerned with here are those used in roofing. While they have their beginnings in acrylic paint, acrylic roof coating has been specially developed for application on roofs. They bond to roofing materials and hold up to the temperature ranges seen on building roofs. This special forumation differentiates them from paint, floor polish, caulking, and other similar acrylic compounds.
Benefits and Features
Acrylic polymer coatings are designed to be applied in a seamless coat across the roof. They can expand and contract with heat and cold, are resistant to impacts from debris and hail, and form a continuous waterproof membranes across the entire roof surface. They maintain flexibility and elasticity, so they seal punctures and cracks in the roof surface they are covering.
This liquid-applied, fully adhered, seamless (monolithic) membrane is formed as the coating dries. Acrylic coatings are typically 15 to 30 mils (.015-.030 inches) thick. PVC roofing, by comparison, is about 60 mils, and house paint is about 3 mils. The material fully adheres to the roof surface it is applied to, and applied with a sprayer or roller.
Acrylic Coatings vs Paint
These roof coatings are applied like paint, using sprayers, rollers, and brushes. And in fact, initially paint was used as a coating. But paint is brittle, and thinner, and did not hold up under the harsh conditions on roofs. So acrylic roof coatings evolved into a different type of polymer with more flexibility, heat tolerance, and durability. These coatings are intended for use on surfaces that may have standing water, foot traffic, etc – things that paint does not hold up well under.
Elasticity
Building roofs may appear solid and sturdy, but they are actually dynamic. They move with temperature changes, wind forces on building, weight of snow and water, and seismic movement under the building. They also get walked on to get to all the things that are typically put on building roofs, like antennas and HVAC equipment. These elastomerics hold up well under these conditions.
Durability
Acrylic polymer coatings are formulated with ultraviolet (UV) blockers, so that they reflect UV light from the sun. UV light is a major factor that degrades asphalt roofs. So, applying elastomeric coatings to asphalt roofs protect them from further deterioration.
Labor to Apply Acrylic Coatings
Since the acrylic coatings are in a water (rather than oil) base, cleanup is easy. They also do not have VOCs (volatile organic compounds), so they are not toxic to the workers applying them, and emit very minimal toxic fumes. They can be sprayed, rolled on, or brushed on, so application is very easy. This helps keep labor costs low compared to many other roofing types.
Cost vs Investment Return
While these coatings may be a little more expensive than asphalt coatings, over the long term the costs are favorable. This is because acrylics don’t degrade under UV light like asphalt does. And since acrylic coatings are white, they reflect heat from the sun also, helping with energy savings on cooling.
Things to Keep in Mind
When comparing types of roof coatings, there are a few things to pay attention to. Some of these are:
- dirt adherence. Dirt darkens the surface and light colored material loses its reflective properties, and therefore its ability to reflect heat.
- adhesion. What kind of surface is it being applied to? Different coatings stick to materials differently, some better than others.
- durability. How well does the material hold up under the local weather?
- submersion. Flat roofs tend to have standing water, and the roof material can be submerged for extended periods. How well does the coating resist effects of submersion in ponding water?
- flexibility. Some coatings are better suited to higher or lower temperatures. Needs are different in Missouri, for example, than in Alaska, or Arizona.
Cooling Properties and Energy Efficiency
Acrylic roof coatings are white, and they reflect light and heat. Since they don’t absorb heat, the surface temperatures of coated roofs are lower than darker colored materials. This translates into measurable energy savings for the building interior. You can read more about cool roofing at the Department of Energy’s page on the subject.
Acrylic coatings typically only raise about 10 degrees F in sunlight, as opposed to as much as 80 degrees for black asphalt roofs (compared to the air temperature). Not only do these roofs stay cooler, but they also do not experience such drastic temperature fluctuations as asphalt. Consider a black roof that is 80 degrees in the morning, rises to 160 degrees in the sunlight, and then it rains and returns to 80 degrees in a matter of minutes. That can stress the roofing materials and cause wear. Acrylic roof coatings don’t have these kind of fluctuations.
Fire Rating
Elastomeric acrylic coatings can be made with fire resistant compounds that can help meet class A fire ratings (in combination with the other roof system components).
Limitations
If the roof surface to be coated is in very bad shape, no coating is going to magically fix it. Some amount of deterioration can be restored, and an experienced roofer such as Cook Roofing Co can help evaluate the condition of the existing roof materials to see if acrylic is a good option for your roof. This includes checking for conditions that may require additional cleaning to ensure that the coating properly adheres.
Conclusions
Water and temperature are also important factors. Since these coatings are water-based emulsions, if it is very cold, the water base can freeze before it dries. If it rains before the material is dry, it would ruin the application. And if there’s high humidity, then it will take longer to dry.
Acrylic coatings can help extend the life of many types of roofs, providing that the existing roof is not in very bad shape. The fact they are generally white can help improve energy efficiency of the building. They can restore waterproofing to an existing roof with less effort than trying to find and patch leaks and penetrations, and do so with a seamless application.
Overall, acrylic roof coatings are a great option to restore many roofs. Contact Cook Roofing Co today, so that we can evaluate your roof and find the best solution for your situation and budget. Call (417) 334-4238 or use our contact form and we’ll get in touch with you as soon as possible.