Roof coating is a membrane layer applied to a roof to provide it with more protection against the elements and seasonal weather conditions. Coating a roof is one of several roof maintenance services that professional roofers offer to extend the lifetime of a building’s roof. Applying the material often involves repairing weak or broken areas before coating the entire roof in a solid layer of the material the client chooses.

There are several coating materials an individual can decide to purchase for their building’s roof, so it’s a good idea to explore coating types and learn about the differences between the materials before choosing one.

Roof Coating Types

There are a few main types of roof coating to choose from, and each type has its strengths.

• Silicone Roof Coating: This coating type is often used in areas that get a good deal of sun and rain, as it does well against UV rays and pooling water on lower pitched roofs. In addition, silicone or Gaco roof coating usually requires less material to complete a thick layer due to its high-solids volume.
• Acrylic Roof Coating: Acrylic is a plastic coating type that’s quite popular because of how durable it is, despite being relatively inexpensive (unless you’re purchasing Polyurethane coating, which is a little more costly than standard acrylic). Acrylic’s reflective surface is a good option for areas that get a lot of sunlight, and this coating type is also resistant to dirt and mildew.
• Elastomeric Roof Coating: Elastomeric coatings, like Butyl, is a strong material that’s both highly reflective and low in permeability. This rubbery solvent is a favorite among commercial roof coatings, but it tends to be more expensive due to its low solid volume.
• Asphalt Emulsion Coating: Asphalt is one of the most common roof coating materials on the market. Because it’s affordable and easy to work with, it’s a staple material for homes and businesses that need extra roof protection. Asphalt can be used as a base for other coating types, but because it is water-based, it is more susceptible to cold weather.

What’s the Difference Between Coating Types?

Not all roof coatings are created equal, and different materials are more suitable for certain locations and roof types. For example, metal roof coating will benefit more from a silicone or acrylic material over an asphalt emulsion material.

Additionally, there are other factors to consider when choosing a roof coating material, which we’ll cover briefly.

Strength

Of course, strength is a crucial component of roof coating preference. Measured in psi (pounds per square inch), a material’s strength refers to the pressure it can handle before it cracks.

Most robust material: Polyurethane or Silicone

Moisture Resistance

A coating’s permeability is the material’s ability to allow liquid or gas to pass through it. At a glance, the coating type’s permeability does not necessarily mean it’s either good or bad at resisting moisture. Permeability and moisture resistance depends significantly on the material itself. Silicone has a low permeability rating, which means it’s resistant to moisture. Yet, the high permeability rating of acrylic shouldn’t suggest the opposite. Instead, it means that acrylic is simply more breathable than silicone.

Highest moisture resistance material: Silicone or Elastomeric

Solid Volume

Solid volume is how much of the coating material will remain on the roof once the product dries. Coatings with high solid volumes will require less material to coat a roof, while those with low volumes will take more material because of shrinkage as the material dries.

Highest solid volume material: Silicone

Emissivity

Roof coatings with high emissivity values can release heat that the surface absorbs more efficiently than coatings with low emissivity values. Emissivity is measured as a decimal point between 0 and 1, and a .65 is considered to be a decent value.

Highest emissivity material: Acrylic, Silicone, or Elastomeric

Reflectivity

Reflectivity is a material’s ability to reflect light. A high reflectivity percentage means that the material reflects a significant amount of light and thus reduces the heat that’s otherwise gained from the sun’s rays beating down on the roof. Light-colored materials are generally great reflectors.

Highest reflectivity material: Acrylic or Silicone

Elongation

Elongation refers to how stretchable a coating material is. The higher the elongation rating, the more enduring the coating will be when it comes to the regular expansion and contraction of the roof. Materials with low elongation values may thin, crack, or peel if the roof expands and contracts.

Highest elongation material: Elastomeric

Roof Coating Cost

Cost is a big part of the decision-making process, and pricing that fits within an individual’s budget is often the defining factor when it comes to coating materials.

Acrylic and asphalt coating are the most affordable coating types, followed by polyurethane. Silicone and Elastomeric coating are more costly coating options. Still, silicone has a higher solid volume, meaning less of the product will be needed to complete a solid layer.

For more information about roof coating materials, it’s wise to seek assistance and professional advice from an experienced roofing company. To save time you’d otherwise spend reading through “roof coating company near me” search results, let Roof Evolution be your one-stop roofing expert.

Give us a call, and we’ll provide you with all of your options and answer any questions you may have.