Does roof coating stop leaks?

coating application

Do roof coatings work?

Roof coating is something that is more common among commercial structures because of their flat roofs. However, it can be used on residential roofing as well, but for the sake of focus in this article, we’ll keep the topic commercial structure oriented. A homeowner with a flat roof should definitely speak to a roofing contractor about roof coating options. 

A roof coating is a monolithic membrane that is fully adhered in a fluid application. There is elastomeric roof coating that is flexible with temperature and building movement, return to its original shape without damage. The typical dry film thickness can vary between 0.075 mm to 1 mm or more, becoming the top layer roof membrane. 

Commercial roof coating and repair is possible if the existing roof is in fair condition Roof coating is known to be a money saver in energy cost, repair bills, and waterproofing capabilities. Many commercial structure facility owners choose roof coating vs replacement when the original warranty as expired. 

What is the best roof coating?

There is no straightforward answer to that question, there are many variables that are considered when choosing a roof coating. The environment, age of the existing roof and its current condition, the roof type, weather conditions, even aesthetics can matter. Here is a list of roof coatings and information about the material.

  • Acrylic Roof Coating: A durable and inexpensive elastomeric coating comprised of high solids emulsion polymers. This highly reflective coating is ideal for structures in a high UV climate. It is mildew resistant and easy to work with, used on metal roof surface including built-up roof, modified bitumen, single-ply, and spray polyurethane foam. Acrylic roof coating can be rolled on or sprayed on, depending on the substrate, it can take up to 2 gallon per 100 square feet. The downside to acrylic roof coating is the inability  to withstand ponding water and temperatures below 50°F. This is a water-base product and cold temps, and water ponding can affect the adhesion and hinder cure time.
  • Asphalt Emulsion Roof Coating: A widely used roof coating for restoration, consisting of asphalt particles that are dispersed in water, clay is added as bonding element. This organic and inorganic compound of asphalt comes in black or brown colors and may include other fillers to give it durability and strength. An inexpensive material that is easy to work with, good for leveling the alligatoring and irregularities that built-up and modified bitumen are known to have. The downside to this roof coating is it may need to be applied in several coating to get the result coverage desired, requiring up to 4 gallons per 100 square feet. It is a water-based product as well and is susceptible to temperatures freezing and below. 
  • Butyl Rubber Roof Coating: This roof coating is known for being extreme longevity and tensile strength. A high reflectiveness, this solvent-based polymer is fast-drying, and is use for commercial roof maintenance and repair. With the low permeability, it makes a good rubber roof coating for a vapor-retardant barrier in cold and freezing temps. Popular use on existing built-up roofs, metal roofs, modified bitumen, single-ply, and spray polyurethane foam. Comes in gray, tan, or white, and requires two gallons for every 100 square feet. Disadvantages of butyl roof coating is the color fades due to low solid content and to get the dry film thickness desired, take more product. Not cost-effective as other elastomeric roof coating and can be challenging to apply for roofing contractors. 
  • Silicone Roof Coating: The preferred choice when  UV protection and ponding water resistance is needed. This has a slow erosion rate compared to other roof coatings, doesn’t become brittle and hard and with newer formulas available today, less is needed to achieve the desired thickness, using less than two gallons for 100 square foot coverage. Available in gray, tan or white and works well on built-up, EPDM,  metal, modified bitumen, single-ply, and spray polyurethane foam existing roofing. Downside to this roof coating is the dirt attraction is fast, affecting the UV reflectiveness if regular roof cleaning isn’t performed. It is an extremely slippery surface when wet and is not tear resistant, suggesting light foot traffic.  Granules can be incorporated into the application that can help minimize possible foot traffic damage. 
  • Urethane Roof Coating: The best in adhesion, durability, and strength of any roof coating material. Impact-resistant and strong to pedestrian traffic, contracts and expands with the temperature and structure movement, resistant to ponding water. The aliphatic type of urethane roof coating is commonly used as topcoat, because of the UV stability, dirt resistance and color retention. The aromatic type is less expensive and best as a foundation roof coating because it isn’t as UV stable. Both types are applied in roll-on or spray application, requiring less than two gallons per 100 square feet. Downside to this roof coating is the challenge to spraying is hard on equipment and has a strong odor. It is constantly curing due to be a moisture based material. 

How long does roof coating last?

It can depend based on the original roofing, the type of roof coating used, the maintenance and upkeep of the roof. Typically, you can expect up to ten years lifespan of a properly applied roof coating. This gives you another 10 years life expectancy to the existing roof. 

How do you apply roof coating?

Again, depending on the type of roof coating used, it can be applied by rolling it on with long handled paint rollers or sprayed on with special equipment. The roofing contractor will discuss the options with you while providing the estimate because that will affect the cost. 

metal roof with coating

Is roof coating waterproof?

As we discussed in the different types of roof coating, not all roof coating materials are waterproof. An elastomeric roof coating when applied properly by a professional roofing contractor can be the better choice for waterproofing. 

Who Does Roof Coating on Commercial Structures? 

You can do an internet search for “commercial roof coating contractors near me” to find a company. You can also ask neighboring buildings who they have used. Your insurance company may have recommendations as well. Call 502-228-7717 today.