Tank spreader applying silicone roof coating to modified bitumen roof

Silicone roof coatings are perhaps the most popular chemistry type in the roof restoration industry—and for good reason! They make a great solution to restore and protect a wide variety of commercial roofing substrates including modified bitumen, single-ply, EPDM, TPO, smooth/gravel BUR, concrete roof decks, and spray polyurethane foam.

When it comes to choosing the best silicone roof coating, there are some important factors to keep in mind. Below, we highlight some notable silicone roof coating pros and cons.

The Advantages

UV Protection

Silicone roof coatings can reflect up to 80-90% of the sun’s harmful UV rays. This means facility managers and property owners can save thousands of dollars by cutting their facility’s cooling costs during the warm summer months and reducing the HVAC system workloads.

Unlike other chemistries, a silicone coating won’t degrade, chalk, or crack from prolonged exposure to direct sunlight. They erode much slower than other elastomeric coatings without becoming too brittle or hard.

Minimizing the sun’s impact on the roofing surface not only helps sustain lower energy costs, but it also reduces internal building temperatures and prolongs roof life.

Flexibility & Weatherability

Silicone roof coating systems provide a highly flexible, seamless, and impermeable membrane capable of withstanding wind-driven sand, oxidation, and extreme temperatures. Being a moisture-cure substance, silicone effectively resists moisture penetration, making it the ideal coating to protect against the damaging effects of ponding water.

High Solids Content

For the most part, modern silicone roofing materials have a high-solids content typically exceeding 95%. This means less material is used during application to achieve the desired dry mil thickness. The ability to apply more coating in a single pass helps save on time and labor costs without compromising workmanship and system integrity.

The Disadvantages

Attracts Dirt

Silicone coatings easily attract dirt and other airborne dust particles. Over time, this accumulation of dirt and dust on the roof surface causes the system to slowly lose its reflective properties. This gradual build-up makes the roof more susceptible to heat from the sun, which negatively impacts cooling costs and internal building temperatures.

We recommend pressure washing a silicone coating system 6-12 months after it’s been installed to remove any dirt accumulation. This typically eliminates the problem of dirt accumulation altogether. If asked, most contractors will build this additional step into the scope of work of their proposal.

Challenging to Spray

As with any solvent-based coating, silicone roof coatings can be difficult on hydraulic spray equipment. If the application equipment is not properly cleaned and maintained, problems during the installation process are more likely to occur.

VIDEO: Click here to learn some essential best practices of working with silicone coatings.

Slippery When Wet

Silicone coatings make surfaces very slippery! If foot traffic is expected, we highly recommend using the American Weatherstar Walk-Path System to clearly mark designated pedestrian traffic areas.

Silicone Roof Coating Products We Provide

Silicone 410

Silicone 410 is a core component of our Ure-A-Sil and Met-A-Sil Systems. This single-component, solvent-borne, moisture-cure, silicone coating provides roof surfaces with a weather-resistant, highly reflective, and rubber-like membrane capable of withstanding ponding water and providing unsurpassed protection.

Learn more about Silicone 410

High-Solids Silicone 412

High-Solids Silicone 412 is the “high-solids” component for our Ure-A-Sil and Met-A-Sil Systems and is the primary component of our Envir-O-Sil System. It shares most of the same performance characteristics as Silicone 410 but is specifically formulated with a higher solids content. This means it takes less material to achieve the desired dry film thickness.

This product also contains less volatile organic compounds (VOCs), which make it the ideal roof coating for areas regulated by strict environmental standards.

Learn more about High-Solids Silicone 412

Conclusion

When it comes to the suitability and performance of a roof coating, it’s important to understand the strengths and weaknesses of the chemistry. Silicone roof coating systems are a highly effective roof restoration solution. There’s a number of key factors to consider when it comes to choosing the best silicone roof coating system for a commercial roofing environment.

Want to know if a silicone roofing system is right for your commercial facility? Click here to schedule a free roof inspection with an American WeatherStar Approved Contractor.