Metal roofs on commercial and residential buildings are durable but need to be protected from rust, corrosion, and general wear and tear. Failure to properly treat your roof can lead to expensive repairs down the line. To preserve the roof and extend its lifespan, apply a roof coating. This page explains the different types of roof coatings to help you choose the right one.
The metal roof coating you choose depends on the material of your roof and what you need from your coating.
Aluminum Roof Coating
Aluminum roof coating is a highly reflective, protective layer designed to shield your roof from the damaging effects of sun, rain, and temperature fluctuations. Formulated with aluminum flakes suspended in an asphalt or acrylic base, this coating creates a durable barrier that reflects up to 60% of the sun's rays, helping to keep interiors cooler and reduce energy costs. Its reflective properties not only improve comfort but also slow down the roof's aging process by minimizing heat-related expansion and contraction.
Contractor's Top Pick: ALCM Aluminum Roof Coating
Experts Say: The ALCM 2# Aluminum No-Fiber Roof Coating is a top choice for metal roofs when long-lasting performance is needed without the rough texture of fibered coatings. With two pounds of aluminum paste per gallon, it offers superior reflectivity and creates a tough, weather-resistant barrier that withstands sun, wind, rain, ice, and snow. It delivers an average reflectivity of approximately 72%, significantly outperforming typical non-fiber coatings, and remains durable in extreme temperatures ranging from -60℉ to +160 ℉.
Similar Products: Kool Seal Premium Fibered Aluminum Roof Coating
Acrylic Roof Coatings: Affordable and Energy-Efficient
Typically, a water-based coating, acrylic is a cost-effective choice known for its ease of cleanup. It is highly reflective and UV-resistant, which helps lower your energy costs during the summer months or in areas with intense heat and sunshine. Because it is a water-based substance, acrylic roof coatings are easy to install. They are ideal for sloped metal roofs, as well as conventional flat roof materials such as modified bitumen, single-ply, EPDM, built-up roofs, and spray polyurethane foam.
Acrylic roof coatings are more susceptible to freezing if applied in colder temperatures. This coating should only be applied in temperatures of 50℉ and rising. Colder temperatures will also slow drying time. They are also not as resistant to ponding water, so ensure your roof has proper drainage.
Silicone Roof Coatings: Ideal for Flat Roofs and Ponding Water
Created by adding solvents and a catalyst to a silicone base, silicone roof coatings can be installed on metal, modified bitumen, single-ply, EPDM, built-up roofs, and spray polyurethane foam. While more expensive than acrylic, silicone is more resistant to ponding. Silicone roof coating also reflects UV rays, reducing energy costs. The material is flexible and can be installed quickly.
Silicone works best on flat roofs. When it gets wet, it becomes slippery. If you expect heavy foot traffic, use walk pads to avoid injury. It can be difficult to spray if the equipment is not well-maintained.
Shop popular types of Silicone coating from Henry, Certainteed, and Kool Seal.
Polyurethane Roof Coatings: Durable and Weather-Resistant
Polyurethane is known for its durability because of its ability to withstand foot traffic, hail, and other extreme weather. Urethane coating is also known for its flexibility; it can expand and contract without cracking or splitting as the weather changes. It works on almost any substrate or roof, whether it is sloped or flat, textured or smooth. Urethane is even used as a base coat for silicone roof coatings by some contractors. It also resists dirt and reflects UV light.
One drawback of polyurethane is that it emits a strong odor. While not harmful, it can be unpleasant for the building's occupants. If your building has a fresh air intake HVAC system, set it to recirculate air from within the building or turn it off completely during the installation process.
It can also be difficult to spray if the equipment is not well-maintained. The roof coating may have a shorter shelf life. Single-component urethane coatings constantly cure, even while in the pail; plural-component urethane coatings will not cure until mixed.
Elastomeric Roof Coatings: Flexible and Long-Lasting Protection
The elastomeric roof coating is highly flexible and can stretch and recover, creating a waterproof and weather-resistant barrier. It can be acrylic, silicone, polyurethane, or another polymer-based material. It provides excellent waterproofing and UV resistance, has a long lifespan (10 to 20 years), and handles temperature fluctuations well. The elastomeric roof sealer is ideal for flat roofs, sloped roofs, and use in various climates.
Elastomeric roof coatings can be more expensive than others and may require primers for substrates like tar and gravel.
Fibered vs. Non-fibered Aluminum Roof Coating
Both fibered and non-fibered roof coatings contain aluminum fibers. Fibered means it is mixed with fibers like fiberglass or organic materials. The fibers enhance the coatings' strength, which makes them more resistant to tears and breaks. The fibers reduce the coating's elasticity and make it harder to spread.
Non-fibered roof coating does not contain added fibers. The coatings have great elasticity and stretching ability when cured. The downside is that they are not as resistant to tears and abrasions.
Metal Roof Coatings: Prevent Rust and Extend Roof Life
These are specifically designed for metal roofs to protect against corrosion, rust, and other types of damage. Metal roof coatings are typically composed of a mixture of polymers and additives. They form a durable barrier that extends the roof's lifespan.