As commercial roofs age, like all materials left exposed to the elements, this weathering can have adverse aging effects on products. These weathering effects can often have adverse impacts on materials effectiveness. While the instinct may be to believe your roof may need to be replaced, often many can be renovated with a more cost-effective and efficient solution which can lie in the application of silicone roof coatings.
This blog post aims to bring clarity to the essence of silicone roof coatings and their relevance to a building owner’s needs. We’ll delve into the characteristics of silicone coatings, differentiating them from other types of roof coatings. Additionally, we’ll examine the advantages and disadvantages of utilizing a silicone coating system, providing valuable insights for informed decision-making.
Why Roof Renovation versus Roof Replacement?
Though there are many reasons to consider roof renovation versus roof replacement, the primary reason can often be it is simply not necessary. Roof renovation with a roof coating system can prolong the existing roofs useful life, keep unnecessary waste from our landfills, set in motion a practice of good future roof maintenance practices, and it can save significant money.
The constant exposure of a building’s roof to various elements over time creates aging, what we often refer to as “wear and tear”. Weather extremes, thermal expansion and contraction, and prolonged exposure to elements like water and UV rays can all contribute to aging wear and tear thereby aging the roof and its various components.
The most effective way to prevent aging due to this exposure, is to protect the roof from that exposure with a roof coating system. Rather than opting for a costly full roof replacement when the existing roof is still largely functional, applying a roof coating presents a more economical solution. These coatings, typically applied in one or two coats, serve to seal minor imperfections in the roof’s surface. Not only are they cost-effective, but they’re also relatively easy to apply.
Protecting the existing membrane roof with a roof coating system effectively removes the process of aging due to exposure. Roof coatings effectively prolong roof life providing added protection. While acrylic roof coatings are among the most common, there are less often discussed benefits to the use of silicone roof coatings, this blog will attempt to help you navigate the array of roof coating options as they can be overwhelming.
Roof Coating Types
Roof coatings are generally categorized into two primary types: asphaltic coatings and elastomeric coatings.
- Asphaltic roof coatings: Typically consist of a base asphalt or bitumen and are best suited for roofs with an exposed asphaltic surface such as a smooth surfaced BUR or MBUR roof. These materials are commonly known as asphalt emulsions and fibered and non-fibered aluminum coatings. These materials have a black or aluminized color and have a limited life cycle.
- Elastomeric roof coatings: Are commonly formulated with acrylic or silicone chemistry. They possess characteristics that are more flexible offering a unique ability to expand and contract along with the roof in response to changing temperatures. This characteristic makes elastomeric coatings more versatile and compatible with a wider range of uses atop a much wider variety of roofing materials and systems.
For the purposes of this discussion, our focus will be on silicone roof coating systems. To provide a comprehensive comparison, we’ll compare silicone coatings with their most common elastomeric counterpart acrylic coatings.
Acrylic roof coatings, while very effective at protecting underlying roof systems and can be quite cost-effective, do have several drawbacks. This type of coating is sacrificial by design and as it ages it is reduced in dry film thickness by oxidizing and washing away that oxidized layer to retain its true color, let’s say white appearing more white.
As the roof is exposed to rain or cleaning, surface dirt washes away with the oxidized layer, typically 1 dry mil of thickness per year on average. This type of coating can result in a shorter lifespan when compared to a comparable silicone coating system. Although acrylic coatings offer good UV protection, their resistance to ponding water is not as robust as silicone.
In contrast, silicone coatings serve as an effective barrier, offering a more robust resistance to standing water and moisture vapor penetration. Polyglass offers an effective range of premium silicone roof coatings suitable for various applications and roof needs, which we’ll delve into further later in this post.
Pros of silicone coatings
Cost-effective
Opting for a silicone roof coating system can be significantly more budget-friendly than undergoing a complete roof replacement. The difference is removing a functional existing roof system and replacing it with new, can be substantially more than a quality roof restoration using a silicone coating system. Silicone coating systems offer a versatile combination of durability, quality, and waterproofing capabilities compared to alternative roof coating options.
Durability
Due to its chemistry, silicone roof coating systems can stand up to harsh conditions that could prove problematic to other coating types. Its flexibility provides a system that can expand and contract harmoniously with the roof. With its inorganic composition, silicone resists becoming brittle and can last for decades.
Environmentally Friendly
Silicone roof coatings rank among the more sustainable choices for coating applications. They boast minimal solvent content and with long life cycles reduce the need for periodic replacement or recoating.
Life-Cycle Performance
Using a silicone roof coating system can add decades to the longevity of a roof. Depending on thickness, coating quality, and application techniques, a silicone coating system may offer up to 20 years of additional protection.
Quick Application
Silicone roof coatings can be quick and easy to apply. Installing a silicone roof coating doesn’t require any heat-based methods, which can pose safety risks. Having a higher solids content than other coatings, silicone roof coatings require thinner layers to create an effective system.
Versatile
Silicone roof coatings are compatible with a wide variety of roofing materials and can be applied to concrete, metal, modified bitumen (MBUR), built-up roofs (BUR), and single-ply roofing systems. Depending on the surface and conditions, a primer is sometimes required.
Water and UV Protection
As compared to other roof coating materials, Silicone roof coatings fare the best against continuous exposure to standing water and rain. The silicone acts as a monolithic layer to prevent water and moisture vapor from penetrating through the system. Silicone coatings protect from damaging UV exposure and can also reflect up to 90% of UV rays from the sun, keeping the building cool and reducing energy costs.
Cons of Silicone Coatings
Though Silicone coating materials are robust and resistant to many common environmental conditions, with any construction product, there are still things to consider when designing a silicone coating system.
Adhesion
Like with most roof coating systems, surface preparation is important and key to adhesion of newly installed materials. The variance in surfaces is why nearly always an adhesion test is recommended before proceeding with work. Re-coating silicone roofing system can pose unique challenges. Adhesion testing in advance is always recommended as not all silicone products achieve satisfactory bond to one another. In rare circumstances, it may be discovered the silicone of choice may not bond sufficiently which could facilitate the need for the removal of the existing silicone coating beforehand.
Gets Dirty
The surface of silicone roof coatings, like other roof coatings tends to airborne contaminates such as dust and dirt, resulting in a roof that appears dull and dirty. Because coatings are of a softer nature airborne This issue stems from the softness of the coating material however such surface materials can easily be washed off.
Loss of Reflectivity
Although silicone roof coatings boast good reflectivity when new, as with all roof surfaces, this can lessen over time as the coating is exposed to the elements and gets dirty.
Slippery
In wet conditions, a roof coated with silicone can become slippery. Due to the nature of the surface of the silicone being uniquely dense, it can be more slippery than some other roof coatings when wet. This hazard is particularly heightened as the slope increases. Safety precautions should always be taken into account when on the surface of any roof.
Vulnerable to Tearing
Although silicone coatings boast a dense and durable dry film, in a non-reinforced state, like other roof coatings, can be subject to tearing conditions. To address areas prone to sheer or tearing effects, reinforcement with fabric can be incorporated into the silicone roof coating.
How Are Silicone Coatings Installed?
Silicone roof coatings are fairly straightforward to install. The entire roof surface must be cleaned first to provide a clear surface for adhesion. The silicone coating is then applied using spray equipment, a brush, a squeegee, and/or a roller at the desired thickness for the individual roof surface.
Explore Polyglass’ Premium Silicone Roof Coatings
As an industry-leading company, Polyglass offers a wide range of silicone roof coatings suitable for any project. Let’s highlight two of our most popular silicone coating products:
Polybrite 90.2
This premium, high-solid silicone coating is a true workhorse and can be applied over several types of roofs. Polybrite 90.2 prolongs roof life by increasing UV protection and strengthening the roof against the elements. It is available in white and Kool Grey variations.
Polybrite 95.1
The Polybrite 95 silicone coating is a solvent-based formula that can increase the lifespan of several roofing types. Polybrite 95.1 enhances a roof with seamless membranes for exceptional water protection and increased energy efficiency.
Experience the quality and durability of Polyglass silicone coatings for your roofing needs. Contact us today to learn more about our products and how they can benefit your project.