Silicone Vs Acrylic Roof Coatings: Which Is Right For Your Roof?

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A quick and easy solution for a leaking or aging roof is the use of commercial roof coatings. However, several types of coatings are available in the market—each with varying formulations, uses, and application methods. Therefore as a property manager, it is crucial to examine the manufacture’s datasheet to determine which product is best suited for a certain project. Specific coatings are acceptable or compatible with certain roof surfaces. 

Silicone and acrylic roof coatings are the most popular options used to solve leak problems and prolong the lifespan of your roof. However, the coating you choose will depend on the roofing condition, systems, and current temperature. 

Knowing the pros and cons of silicone and acrylic coatings can also help you make the right decision. Compare the coating sheen, ease of use, environment safety, and ponding water resistance.

Roof Coating Comparisons - Triton TV - YouTube

1. Coating sheen

Both silicone and acrylic coatings give a beautiful coat in the first week of application. But, the difference comes after several years. How can the coating hold over long periods?

Acrylic roof coatings

A major benefit of acrylic coating is that it can hold out for longer periods compared to silicone. This is because the acrylic-based materials used to make the coat have excellent resistance to solar radiation and can withstand hail. In addition, the coats can also withstand the dimensional instability of most roof membrane surfaces.

Also, studies have shown that properly formulated acrylic coatings hold up their reflectivity over a long time. It reduces temperature as much as 20 degrees F surface temperature when exposed to sunlight at 85 degrees F. This will keep your house cooler and save you AC costs.

Silicone roof coatings

These coatings are made from high solids dispersion of 100% silicone. Due to the nature of silicon products, the coatings start compiling dirt and yellow appearance after just a few years. The dirt and grime collected kill reflectivity after a short period. This also reduces the aesthetic appeal of your roof. 

Since they gather dirt and dust, silicone coatings require routine maintenance, which can be very expensive in the long term. Also, the coatings are very slippery, and they require you to install a walk pad in high-traffic areas.

2. Coat application

Silicone roof coating

One of the major advantages of silicone roof coating is that you can apply an extremely thick coating at a high millage, sometimes with only one coat. While silicone coating provides high millage, they are more difficult to apply and often requires a second coat. 

Since the coatings are thick and sticky, the applicators have a lot of difficulties when rolling out. Also, the coating requires heavy-duty application equipment that many local contractors might not have. The application process requires a solvent clean-up, often with mineral spirits that are more toxic than water clean-up. 

Silicone Roof Coatings
Silicone roof coating.

Due to silicone being moisture-activated, it is not advisable to apply the coat on high moisture days. This is because of the risk of the silicone coat dying up and solidifying.

Acrylic roof coating

Acrylic coatings can be applied in one or more coats. You can spray the coat with basic sprayer equipment. Where you only require the application of basic water clean-up. 

Acrylic coatings should not be applied in cold and freezing temperatures or when they might rain within a specific duration of application. This is because cure time for acrylic coatings is highly weather dependent and cold weather or high humidity will interfere with the curing process. The best weather conditions for curing acrylic coatings are during warm weather or low humidity.

3. Pounding water

Silicone roof coating

Silicones have better resistance to advanced weather conditions and barely become hard or brittle. One factor contributing to the popularity of silicon roof products is that they can withstand long-term exposure to pounding water. 

The coating also offers protection against UV light in extreme temperatures and can resist oxidation. 

Acrylic roof coating

Due to their water base makeup, this is one of the main disadvantages of acrylic roof coating: it cannot withstand ponding water. The coating can become brittle and delaminate from the roof when exposed to ponding water over a longer period.  

Acrylic Roof Coatings
Acrylic roof coating.

Thus, it is advisable to use acrylic coatings for flat roofs with excellent drainage. Flat roofs with poor drainage will require silicone coatings, or you can use acrylic coatings with fabric embedded for optimal performance.

4. Cost

Silicone products are pretty expensive compared to their other competitors. They are, on average, two to three times the amount of acrylic roof coatings. 

However, with more suppliers entering the silicone market, there has been an increase in competition which has led to a decrease in silicone’s price. But, a decrease in quality is evident in the cheaper products.

5. Environmental safety

When comparing the two coats concerning the environment, acrylic coatings are the winner. The main difference between the two coats is that silicone requires chemical solvents, while with acrylic coatings, this can be replaced with water. 

The acrylic coating has about three times lower composition of a volatile organic compound than silicone coatings. They also have less odor.

Conclusion

Every project is unique and requires different coatings. Both silicone and acrylic coating are great options. The acrylic coating is more cost-effective and long-lasting, while the silicone coating is excellent for severe ponding weather.

Author Bio

For the past 20 years, American High Tech Roof Coating has been owned by Javier Chavez who runs their company throughout the Los Angeles, California Area servicing commercial buildings that require new roofs but opt into silicone cool roofing instead.