Roof deterioration and constant maintenance can be major challenges for anyone managing a commercial or industrial building. Whether you've encountered leaks after a rainstorm or have had to deal with peeling, cracking, or blistering roof materials due to sun exposure, you understand the frustrations and potential costs of a bad roof. 

In many cases, silicone roof coatings can end these problems for good.

With over 20 years of experience in providing cutting-edge commercial roofing solutions, At GIDEON, we've seen first-hand the incredible impact that the right roof coating can have on the longevity and durability of a roof, and in this article, we're going to give you a broad and deep overview of this innovative roofing system.

We will dive deep into the benefits and drawbacks of these coatings, explore different silicone chemistries, and help you understand when silicone coatings might be the right fit for your specific roofing needs. 

What Are Silicone Roof Coatings?

Silicone roof coatings are a type of elastomeric coating - a fluid-applied coating that cures into a hard yet flexible membrane that protects your roof from the elements, including wind, sun, rain, and hail.

Silicone roof coatings are made from silicone polymers and crushed rocks. This composition results in a highly durable, flexible, and resilient material that can adhere to a vast array of roofing surfaces, including metal, spray polyurethane foam (SPF), and built-up roof (BUR) systems.

The great advantage of a silicone roof coating system is that it "locks your roof in time" by covering it with a seamless, watertight membrane that can be renewed again and again, eliminating the need for costly roof tear offs and replacements and substantially reducing maintenance costs.

The effectiveness of a silicone roofing system comes down to its unique physical properties. Silicone is known for its impressive flexibility and elasticity, which allows it to expand and contract with fluctuating temperatures without cracking or losing its integrity.

Moreover, silicone roof coatings are considered the most UV stable products in commercial and industrial roofing. They maintain their physical properties even under constant sun exposure, reducing the risk of chalking, degradation, and loss of adhesion.

Why Choose Silicone Roof Coatings? The Benefits

1. UV Stability and Longevity

One of the significant advantages of silicone roof coatings is their exceptional UV resistance. They are the most UV stable products available in the roofing world, making them ideal for areas with high sun exposure.

2. Superior Water Resistance

Silicone coatings are highly water-resistant. They are impervious to ponding water and will not become saturated no matter how long they are submerged. This feature makes them an excellent solution for roofs that have issues with standing water or roofs in regions with high rainfall.

3. Flexibility in Application Conditions

Unlike other roof coatings, which cannot be applied when temperatures drop below 50 degree fahrenheit, silicone can be applied in almost any temperature. This flexibility makes it a good choice for colder climates or during cooler times of the year. Additionally, the fact that silicone coatings are a "moisture cure" means that the more heat and humidity in the air, the faster the coating will "set," avoiding run-off and speeding up the installation process.

4. Energy Efficiency

While silicone roof coatings may absorb some dirt and other residues, reducing their reflectivity over time, they initially have a high degree of reflectivity. This characteristic can help reduce heat absorption, leading to lower energy costs.

5. Versatility

Silicone roof coatings can be applied to a variety of roof types, including built-up roofs (BUR), metal roofs, and single-ply membranes, among others. This versatility makes them a convenient and practical option for a wide range of roofing projects.

6. Environmental Considerations

While traditional silicone coatings have higher VOCs (volatile organic compounds) than other coatings (like acrylics) due to their solvent-based nature, the recent introduction of "high solids" silicone coatings has significantly reduced their environmental impact. These newer coatings contain a higher percentage of solid material, which means less solvent is used, thereby reducing the amount of VOCs emitted during application.

Furthermore, silicone's long lifespan means that fewer reapplications are needed, also reducing its overall environmental impact.

The Drawbacks of Silicone Roof Coatings

Despite their many advantages, silicone roof coatings are not without their downsides. Understanding these can help you make a balanced and informed decision. Here are some of the common drawbacks associated with silicone roof coatings:

1. High Initial Costs

Silicone roof coatings tend to be more expensive upfront than some other types of roof coatings. While the longevity and durability of these coatings may justify the investment over time, the initial price tag may be prohibitive for smaller budgets.

2. Tendency to Accumulate Dirt

Silicone coatings, while incredibly resilient, have a tendency to attract and accumulate dirt over time. This can cause them to discolor, often turning a brownish hue, which can damage your building's aesthetic appeal.

Reflectivity Reduction

The aforementioned accumulation of dirt can also affect the highly reflective, properties of silicone coatings. Over time, the reduced reflectivity can compromise the coating's ability to repel heat.

Difficult Installation Process

Applying silicone coatings can be more labor-intensive and complicated compared to other materials. The coating can gum up application equipment and requires chemical solvents for clean-up, adding to the complexity and potential cost of the installation process.

Slippery Surface

An oft-overlooked downside of silicone roof coatings is the potential safety hazard they can pose. The surface of a silicone-coated roof can be very slippery, especially when wet, making the roof dangerous for maintenance personnel and other technicians who need to access roof inventory.

Not As Environmentally Friendly as Acrylic Roof Coatings

Though recent advances in silicone technology have resulted in "high solids" silicone coatings with fewer VOCs (volatile organic compounds), they can still contain more VOCs than water-based alternatives like acrylic coatings.

The Different Chemistries of Silicone Roof Coatings: Oxime and Alkoxy

Silicone roof coatings are manufactured using one of two chemistries - Oxime and Alkoxy.

Oxime Silicone Coatings

The Oxime formulation is the more traditional of the two chemistries and is widely used by most silicone coating manufacturers. A significant characteristic of Oxime-based silicone coatings is that they release Methyl Ethyl Ketoxime during the curing process, a volatile organic compound (VOC).

Though this chemical accelerates the curing process, it is also a known carcinogen, which can raise environmental and health concerns. Despite this, Oxime silicone coatings are known for their superior durability and longevity, making them a common choice in commercial and industrial roofing projects.

Alkoxy Silicone Coatings

Alkoxy-based formulations are gaining popularity for their lower environmental impact. Instead of releasing Methyl Ethyl Ketoxime, Alkoxy silicone coatings release Methanol during the curing process. Methanol is non-carcinogenic, making Alkoxy the more environmentally friendly option.

Moreover, Alkoxy silicone coatings are solvent-free and emit less odor than Oxime, making them a more comfortable choice for populated areas or projects with strict environmental regulations. They also retain the durability and UV resistance associated with silicone coatings.

Oxime vs. Alkoxy: Which is Better?

The answer depends on the specific needs and constraints of your project. If environmental impact and low VOC emissions are a top priority, Alkoxy silicone coatings could be the best fit. They offer all the benefits of silicone coatings while minimizing environmental impact.

On the other hand, if durability and lifespan of roof life are your primary concerns and VOC emissions are less of a factor, Oxime silicone coatings could be a suitable choice. They have a proven track record in demanding commercial and industrial roofing applications.

In the end, both Oxime and Alkoxy silicone coatings offer excellent performance and durability, with their main difference being their environmental impact and VOC emissions.

When to Choose Silicone Coatings: Understanding Your Roof’s Specific Needs

The choice between silicone and other roof coating materials depends significantly on your unique roofing needs and circumstances. Here are several situations where silicone coatings may be the optimal choice:

Dealing with Ponding Water

If your building has a flat roof that's prone to pooling or standing water, silicone's superior water resistance can help mitigate these issues and prevent potential leaks. Silicone remains impervious to water, even under long-standing ponding, making it a reliable solution for such scenarios.

Cold Weather Applications

Unlike many other coating options, silicone coatings can be applied even in lower temperatures, offering greater flexibility for projects in colder climates or during cooler times of the year.

Longevity and UV Stability

If your roof's exposure to harsh sunlight is a concern, silicone coatings can be your best bet. They are designed to withstand UV radiation without chalking or degrading prematurely.

Low Maintenance Requirements

Given their durability and longevity, silicone roof coatings can be a cost-effective solution in the long run. They are less likely to require frequent maintenance or reapplications compared to some other types of coatings.

If Aesthetics Are Not a Priority

Silicone coatings tend to accumulate dirt and lose their color over time, which can affect the appearance of the roof. However, if aesthetic appeal is not a significant concern for your project, this downside of silicone coatings may not be a problem.

Silicone Coating Installation Process

The installation process of silicone roof coatings, while potentially more challenging than other types of coatings, comes with its unique advantages. It's important to understand the procedure fully, along with the challenges and advantages it presents, to ensure a smooth application process and durable final result.

The Installation Process

The process begins with a thorough cleaning and inspection of the existing roof. Any loose debris is removed and the roof is cleaned, typically with power washing, to ensure the surface is clean and dry. Afterward, any necessary repairs are carried out. This might involve patching holes or sealing seams.

Next, a primer is applied to enhance adhesion. Not all silicone coatings require a primer, but in many instances, a primer can enhance and extend the life, lifespan and performance of the coating.

Once the primer has dried, the silicone coating is applied. This can be done using a roller for smaller areas, or a sprayer for larger roofs. The coating must be applied uniformly across the entire roof surface, with special attention given to areas around vents, chimneys, and other rooftop installations.

Challenges in Installation

One of the significant challenges during the application process is the potential for overspray. If silicone coating is sprayed, it can drift in the wind and land on surrounding cars, inventory, or other surfaces. Silicone overspray can be extremely difficult and costly to remove.

Another challenge is the cleanup process. Silicone coatings can gum up application equipment and require specific cleanup procedures using mineral spirits. If not properly cleaned after each day’s use, the equipment can become unusable overnight.

Applying Silicone Coatings at Lower Temperatures

An advantage of silicone roof coatings is the flexibility they provide when it comes to application temperature. Unlike other coatings, such as acrylics, silicone coatings can be applied at temperatures below 50 degrees Fahrenheit. This benefit means that silicone roof coating systems can be applied throughout more months of the year, even in colder climates.

The "Moisture Cure" Benefit

Silicone roof coatings have a unique characteristic known as "moisture cure". This means that the more heat and humidity in the air, the faster the coating will set. This property can help avoid runoff, ensuring that your coating stays where you want it and cures more efficiently.

Overall, while the installation process of silicone coatings may be more challenging than that of other materials, understanding the process and challenges can ensure that you're prepared. With the right precautions and awareness, these challenges can be effectively managed for a successful installation.

Overall, while the installation process of silicone coatings may be more challenging than that of other materials, understanding the process and challenges can ensure that you're prepared. With the right precautions and awareness, these challenges can be effectively managed for a successful installation.

The Upshot

Navigating through the complexities of roofing solutions can be daunting. However, with GIDEON's in-depth exploration of silicone roof coatings, you're now equipped with essential knowledge on their advantages, limitations, specific chemistries, and whether this solution may be right for you.  Whether you're ready to proceed or still have questions, feel free to reach out to GIDEON for a free, 30 minute consultation or additional resources—we're here to assist you.