Is your commercial roof sun damaged?

The hottest part of summer is upon us which means your commercial roof is facing its #1 enemy: the Texas sun. The summer heat can cause serious damage that may go unnoticed until leaks develop in the rainy season. Your roof takes a beating every summer from UV rays, radiation, and thermal expansion. 

Signs of sun damage on your roof.

There are several signs that your commercial roof has sun damage. It is a good idea to inspect your roof before, during, and after the summer season. Regularly scheduled inspections will allow you to catch any sun damage before it becomes a larger, more costly problem. Here are four things to look for when inspecting your roof:

1. Discoloration: Fading or discoloration is a warning sign that your roof needs professional attention. Inspecting any areas shaded by trees or other buildings will make it easier to identify discoloration.  
2. Cracking: Cracks may appear in all different types of roofing materials. Shingles will often curl up and crack from the heat. A roof membrane, such as thermosets, will start to dry up, shrink, and crack along the edges and seams.  
3. Decay: Most commonly found in shingle roofs, decay sets in where moisture has invaded the shingle. The heat then causes the shingle to break down and decay.
4. Leaks: Obviously, any signs of water damage at the end of a long period of extremely hot weather means that your roof needs immediate attention and repair. 

What causes sun damage?

Extremely powerful infrared radiation and ultraviolet light are the root cause of all sun damage, whether it pertains to your commercial building or your skin.

Infrared Radiation

IR radiation can cause drastic swings in the temperature of your roof. During the hot summer days, the sun’s IR radiation can heat the surface of the roof to over 150° F, then drop down to under 90° within 8 to 12 hours. Your roof expands as the temperature rises and quickly contracts as it cools overnight. This fluctuation may cause the membrane, flashings, and fasteners to fail if they loosen or crack under the pressure of repeated expansion and contraction. 

Ultraviolet Light

Ultraviolet or UV light can dry out your commercial roof which leads to cracks and bigger problems if ignored. Asphalt roofs or BUR roofing systems are more susceptible to UV sunlight damage. These types of roofs have oils in the asphalt which can be oxidized by UV light, causing your roof to become dry and brittle. The BUR system could also potentially melt and become thinner. If the asphalt starts to break down and weaken, the entire roof system is in jeopardy and you face the risk of mass water damage with one heavy rainfall.  

How can you protect your roof from the sun?

The best way to protect your commercial roof is with a roof coating. Having your roof properly coated can give you peace of mind during the harshest summer months. With so many options on the market, how do you know which coating is right for you? This depends largely on what type of commercial roof you have on your building and your area’s climate. 

The four types of roof coatings:

1. Acrylic Coating: Acrylic coating is a water-based, cost-effective solution that can be used on a variety of commercial roof types. Acrylic is a good value and is effective in most climates. It is highly reflective, UV resistant, easy to apply, and is an excellent value for performance. One drawback is that acrylic does not perform well when exposed to standing or ponding water. Acrylic coating is a popular choice in dry climates like Texas, but you may think twice about using acrylic coating in wet climates like the Pacific Northwest.
2. Polyurethane Coating: For high traffic commercial roofs where impact resistance is very important, consider a polyurethane coating. There are two types of polyurethane coating: aromatic and aliphatic. Aromatic coatings are less expensive but are not UV stable and can break down under long-term UV exposure. In climates like Texas, this type of coating is not recommended but may be used as a base coating. Aliphatic coatings are UV stable and provide a cleaner, more complete look compared to other coatings. A combination of an aromatic base and an aliphatic top coat provides protection that is very durable, resistant to water, keeps roofs cool due to the reflective nature of its light color, and clean in appearance. This level of protection comes with a cost. Polyurethane coatings are generally more expensive to install than other options, but may be cost-effective in the long-run.
3. Silicone Coating: A silicone coating is a silicone-based roof coating that has excellent durability and water resistance. It is less expensive than a Polyurethane coating and more water resistant than an acrylic coating. However, silicone has a tendency to collect debris and dirt and will lose its reflective properties over time. When it comes time to replace a silicone coating, applying a new coat can be challenging due to the nature of the silicone’s adherence. You must first remove the entire first coating to ensure that the new coating will adhere to the roof. A second coating is possible using silicone that is compatible with the first coat, as long as the roof is thoroughly cleared of debris and dirt.
4. Butyl Coating: A butyl coating is solvent-based elastomeric polymer that is common for a wide variety of commercial roofs. This type of coating has excellent elongation and tensile strength. Once applied to the roof and cured, it forms a flexible, durable, and seamless membrane on the roof. This membrane is able to withstand the expansion and contraction of the roof during periods of extreme temperature fluctuations. Butyl coating is able to reflect up to 90% of the sun’s UV rays. This can lead to significant energy cost savings and extends the life of the roof. The two drawbacks to a butyl roof coating are (1) high upfront expense due to installation costs and the sheer amount of polymer required to achieve an effective layer and (2) it can be challenging to install because of the way it is sprayed on to the roof using hydraulic spray equipment.

Make the effort to protect your roof from the sun.

Sun can cause extensive damage to your commercial roof. It makes good business sense to do everything in your power to keep that from happening. We recommend having your roof inspected by a professional multiple times a year, at least quarterly. A roof coating is an excellent investment that will prolong the life of your roof and lower your costs over the long-run. Work with your roofing professional to select the roof coating that works best for your type of commercial roof.