What is elastomeric roof coating?

White roof coating being sprayed on.

A Durable Choice in Roof Coating

Most commercial structures are large, spanning structures and leading to the need to make sure those roofs are durable, strong, and waterproof as necessary. The weather in Georgia can go from the hot sun bearing down in the summer to winter snow piling up on top of your roof with hail, high winds, and rain in-between. That is why so many building owners choose to have an elastomeric roof coating installed on their roof. If you’re interested in the installation of an elastomeric roof coating in Jasper, GA you can learn more from the Force Field Roofing team by calling 706-301-8630.

What is elastomeric roof coating used for?

An elastomeric roof coating is installed over the existing flat roof of a commercial structure, creating a protective membrane. The elastic properties of the roof coating allow the membrane to flex with the building and temperature, and then return to its original shape undamaged. 

The membrane will be either white or grey in color, depending on the owner’s choice and the climate of the area. Colder regions tend to go with grey to help keep warmth inside the structure. In regions where it’s hot, building owners will go with white for the reflectivity. 

Does roof coating stop leaks?

Yes, when applied properly and maintained. Elastomeric roof coatings are produced from polymers and form extremely large molecules that are typically in an amorphous state. Elastomeric roof coating comes in acrylic, butyl, polyurethane, and silicone to create a waterproof seal when applied to a commercial roof. We’ll explain the differences between types a little later. 

Is elastomeric roof coating waterproof?

As the name suggests, elastomeric roof coating has elastic properties within the membrane. Those properties effectively seal up any leaks, within reason, and prevent any existing damage from getting worse. Elastomeric roof coating is a durable and versatile material and elastomeric roof coating contractors can apply this material year-round as long as the weather isn’t posing a danger, i.e. with lightning and high winds. 

What is the best elastomeric roof coating?

Selecting the best elastomeric roof coating will depend on various factors for each roofing environment. Factors include the age and type of roof, the aesthetics, environmental concerns, and the typical average weather. Here is an overview of the more common types of elastomeric roof coating, and the pros and cons of each.

Acrylic Elastomeric Roof Coating 

Acrylic elastomeric roof coating is popular for its durability and low cost. It consists of high solids, emulsion polymers, and powerful biocides, and provides a high reflectiveness that is recommended for climates with extreme UV rays. Resistant to dirt accumulation and mildew, it is often installed to restore an existing metal roof surface.

This type works well with several roofing substrates like built-up, modified bitumen, single-ply, and spray polyurethane foam roofing. Contractors like the ease of working with this material as it can be rolled or sprayed on. Owners like the options of color offered.

Acrylics are not good for roofs with ponding water issues and should only be installed on a roof with clear and positive drainage. Applying it in a cold temperature below fifty degrees can hinder adhesion to the substrate and slow the cure time.

Asphalt Emulsion Elastomeric Roof Coating

This is a widely used elastomeric roof coating for restoration because the asphalt particles, when dispersed in water, create a bonding agent with the clay. It comes in black or brown, and it is a durable and strong material when organic compounds, inorganic compounds and other fillers are added. 

Commercial roofing contractors like the material’s ease to work with and the inexpensive price is a favorite for building owners. It is often used to level an existing roof that has “alligatoring” and other irregularities found on built-up and modified bitumen roofing. 

It can work as a stand-alone roof material but is more commonly used as a monolithic foundation membrane and paired with elastomeric roof coating products that offer reflective features and UV stability. It typically takes contractors several passes to get the best results, using up to four gallons for 100 square feet of roofing. A water-based product, it will freeze, so applying it in cold weather is not recommended.

Butyl Rubber Elastomeric Roof Coating

Butyl Elastomeric Roof Coatings are known for their intense strength, both elongation and tensile. A highly-reflective and fast-drying solvent-based polymer, it makes roof maintenance and repair easy. It is also excellent for a vapor-retardant barrier when installed over spray polyurethane foam systems for applications of cold storage/freezers.

A Butyl Elastomeric Roof Coating system is ideal for several commercial roof surfaces like BUR, modified bitumen, metal, single-ply, and spray polyurethane foam. This roofing membrane comes in gray, tan, or white, and is rolled or sprayed on using approximately two gallons for every 100 square feet.

The primary disadvantages of Butyl Elastomeric Roof Coating is the color stability and low solids content. More material is needed to achieve the required dry film thickness, making it one of the more expensive of all Elastomeric Roof Coatings. 

Silicone Elastomeric Roof Coating

Silicone Elastomeric Roof Coating is the number one choice for building owners looking for ponding water resistance and UV protection. It has a slower erosion rate than many choices and modern silicone formulas have a high-solids content of more than 90 percent, meaning it doesn’t take as much to get the desired thickness. 

Silicone Elastomeric Roof Coating has a solvent added with a catalyst to the silicone base and comes in gray, tan, or white. It works well BUR, modified bitumen, EPDM, metal, single-ply, and spray polyurethane foam roofing. 

Silicone Elastomeric Roof Coating does attract dirt easily, causing it to lose its reflectivity if regular cleaning and maintenance aren’t done. It is also slippery when wet and tears easily in the right conditions. A roof that has a lot of foot traffic should not use this roofing membrane. 

Urethane Elastomeric Roof Coating 

Urethane Elastomeric Roof Coating is the best when adhesion, durability, and strength are needed. It is an impact-resistant coating that can handle pedestrian traffic and contracts and expands with the temperature without issues of ponding water.

Within the Urethane Elastomeric Roof Coating group are two types: aliphatic and aromatic. The aliphatic is the topcoat because it is the more UV stable option, is dirt resistant, and holds its color. The aromatics type is cheaper but not as stable to UV rays and is best used for the foundation coating when restoring a roof system. Both can be rolled or sprayed on using less than two gallons per square foot, but are hard on spray equipment if not cleaned immediately after use. As the urethane material is in the pail waiting to be applied, it is curing, so speed is of the essence for contractors. 

View from above of a flat roof with a white roof coating.

In Closing …. 

Can elastomeric roof coating be painted? Yes, with proper cleaning and preparation, and the right conditions, a weathered elastomeric roof coating can be refreshed with high-quality exterior acrylic latex paint. It is important to know that elastomeric coating itself is not a paint, which most commercial roofing contractors are aware of. 

And can an elastomeric roof coating be tinted? Yes, a quality brand of universal color tint can be added before elastomeric roof coating installation. Typically two ounces per gallon is needed. If you would like more information or are ready to schedule elastomeric roof coating in Jasper, GA, reach out to the Force Field Roofing team by calling 706-301-8630 today.