When it’s time to restore or protect a commercial flat roof, property managers have two widely used coating options: acrylic and silicone. Both offer protection, energy savings, and extended roof life, but they’re not the same. The best choice depends on your building's location, current roof condition, and long-term maintenance goals.
This guide breaks down the key differences between acrylic and silicone roof coatings to help commercial property managers make an informed decision that aligns with their roofing needs and budget.
What Is Acrylic Roof Coating?
Acrylic roof coating is a water-based solution made from acrylic polymers, various pigment and other additives. It’s designed to reflect sunlight, reduce roof surface temperature, and protect the roofing substrate from UV damage and weathering. It’s most often used on metal roofs as well as smooth-surfaced low slope commercial roofs such as modified bitumen, built-up roofing (BUR), and single-ply membranes.
KARNAK manufactures a variety of acrylic roof coating products that help extend roof life while lowering cooling costs, making them an attractive choice for energy-conscious property managers.
What Is Silicone Roof Coating?
Silicone roof coating is a solvent-based solution made from silicone polymers, various pigments and other additives. It forms a seamless, waterproof layer that performs well in ponding water situations and harsh weather environments. Silicone is often used on roofs that already have poor drainage or have frequent exposure to heavy rain.
While both coating types offer protective benefits, their chemistry, application process, and performance differ significantly.
Durability and Weather Resistance
Acrylic Roof Coating
Acrylic coatings are designed for UV protection and high reflectivity. They offer some of the best color and reflectivity retention of any fluid-applied roof coating. These coatings perform best in areas with moderate to low rainfall. They can resist some water, but they’re not ideal for standing water or roofs with chronic ponding.
With proper installation and maintenance, a quality acrylic roof coating can last 10 to 15 years, or more when additional coating is applied, before needing a recoat.
Silicone Coating
Silicone coatings excel in extreme weather conditions. They maintain their flexibility and performance even after exposure to heavy rain, ponding water, or prolonged sun. Silicone is less likely to degrade under standing water, making it ideal for areas with frequent storms or poorly sloped roofs.
Silicone coatings can also last 10 to 20 years depending on thickness and climate, but they can be are harder to recoat once the surface becomes dirty or slick. Dirt retention can also reduce the coating’s reflectivity over time.
Application Process
Acrylic Roof Coating
One major advantage of acrylic roof coating is ease of application. It cleans up with water, which makes the process faster and more eco-friendly. It typically requires dry weather during application and drying.
The coating is often applied in two or more layers, with drying times ranging from a few hours to a full day depending on humidity and temperature. Because it’s water-based, it should not be applied if rain is expected within 24 hours.
Silicone Coating
Silicone coatings are more forgiving when applied in humid conditions, making them useful in unpredictable climates but they should still always be applied to a dry surface. Cleanup requires solvents, and the thick material can be more difficult to spray or roll. It often only requires a single coat due to its high solids content, but it must be installed carefully to avoid oversaturation.
Reflectivity and Energy Savings
Both coating types are reflective, helping to reduce rooftop heat and improve building energy efficiency. However, acrylic roof coating typically offers higher solar reflectivity, especially when white or light-colored. It’s often chosen for buildings with high cooling costs or heat exposure from long sun hours.
According to the U.S. Department of Energy, reflective roof coatings like acrylic can significantly reduce roof surface temperature and help lower HVAC load during hot months. This makes it a popular option in dry, sunny regions where cooling efficiency is a priority.
Silicone coatings are also reflective but may attract more dirt and lose some of their reflectivity over time. This can reduce their long-term energy-saving benefits unless regularly cleaned.
Maintenance and Recoating
Acrylic Roof Coating
Maintenance for acrylic roof coating is relatively simple. Over time, recoating is straightforward since new layers adhere well to previous applications. Cleaning usually involves pressure washing and patching any worn areas before applying a new layer.
The ability to recoat without aggressive surface prep can lower future maintenance costs, especially on large commercial buildings with wide roof spans.
Silicone Coating
Recoating silicone is more challenging. New silicone won’t always adhere well to aged silicone unless the roof is thoroughly cleaned. Dirt buildup can interfere with adhesion, and in some cases, the roof needs to be chemically cleaned with a solvent such a denatured alcohol.
If your maintenance plan involves periodic recoating as a cost-saving strategy, acrylic roof coating may offer more flexibility and affordability.
Cost Comparison
Initial costs vary depending on roof size, condition, and geographic location. In general, acrylic roof coating is more cost-effective upfront. Material costs are lower, and application labor tends to be faster and simpler.
Silicone coatings tend to have a higher per-gallon price, and the equipment and labor required for installation may also increase the total project cost. For property managers with multiple roofs or large square footage, the long-term financial impact can be significant.
However, if your building is in a location prone to ponding or heavy rainfall, the extra cost of silicone might be justified by lower risk and fewer repairs.
Environmental Considerations
Acrylic coatings are water-based and low in volatile organic compounds (VOCs), which makes them an environmentally friendly choice. Cleanup is easy with water, and disposal is less hazardous compared to solvent-based materials.
Silicone coatings, while solvent-based, have typically similar VOC content to acrylic coatings. Disposal and cleanup often require chemical solvents, which may be a concern for facilities with sustainability initiatives.
If your building adheres to LEED standards or state energy codes, both acrylic and silicone roof coatings can contribute to energy credits and green building goals.
Final Thoughts: Which One Is Right for You?
There’s no one-size-fits-all answer. Both acrylic and silicone coatings have strengths, and the best choice depends on the specific needs of your roof. If you manage a property in a dry, sunny region and want an affordable, energy-efficient solution, acrylic roof coating is a smart investment. If your roof holds water and sees frequent storms, silicone may offer better long-term protection despite the higher cost.
The most important step is working with a manufacturer or contractor who understands commercial roof systems and coating performance. KARNAK has decades of experience helping property managers protect their roofs with reliable solutions built to last.
Contact KARNAK for Roof Coating Solutions
Still weighing your options? Contact KARNAK to speak with a technical representative about your roof’s condition and which product is right for your building. Whether you're planning a coating project this season or preparing a long-term maintenance strategy, our team can help you make the best choice.
Frequently Asked Questions
1. Can acrylic roof coating be applied over an existing roof system?
Yes. In many cases, acrylic roof coating can be applied directly over existing roofing materials like modified bitumen, EPDM, TPO, PVC, metal or built-up roofing. However, the surface must be cleaned, dry, and in good enough condition to support the coating. A roof inspection is always recommended to confirm compatibility.
2. How long does acrylic roof coating last on a commercial roof?
A properly applied acrylic roof coating can last between 10 and 15 years. Longevity depends on roof conditions, climate, and the thickness of the application. Regular inspections and timely recoating can extend performance well beyond the initial life expectancy.
3. What are the main limitations of acrylic roof coating?
The biggest limitation is its sensitivity to ponding water. Acrylic roof coating isn’t ideal for roofs with poor drainage or frequent standing water. It also requires dry weather for application and curing, which may affect timing in regions with high humidity or rainfall.
4. Can acrylic roof coating be applied overtop silicone coating?
No, once silicone coating has been applied it can only be recoated with silicone. On the other hand, acrylic roof coating can be coated over with silicone. A primer or base coat may need to be applied first. An adhesion test should be performed to verify adhesion.
