Roof Coatings
Qualified roof coating products lessen the need for air conditioning in commercial structures and can cut energy costs in half. The legislature offers tax incentives for commercial builders that make use of energy-saving innovation, including cool roof coatings.
Lighter colored (white) roof coatings reflect the suns heat and UV rays and often lower the temperature of the roof by up to 100° degrees F.
The most common cool roof coatings used over sprayed polyurethane foam (SPF) and other roof deck surfaces are light/white colored. The most common types are Acrylic, Silicone, Urethanes, Polyurea.
During warmer summer months, temperatures can reach 170° degrees F on a low-slope black asphalt roof, and they can drop to -20° degrees F during the winter in northern and higher elevated regions. Much of the heat generated by absorbing the sun’s ultraviolet (UV) radiation transfers to the building interior, and can have significant adverse effects on energy consumption.
Installing Cool Roofs in cities can have significant positive impact on the environment as well. Urban Heat Zones are caused in part by a significant number of large dark colored roofs in urban areas that can reach extremely high temperatures. This macro heat effect from hot buildings and pavement causes smog, increased energy consumption and discomfort to building occupants . A cool roof can help save the environment and save money. Many states offer utility discounts and rebates to building owners who install cool roofs.
It is virtually impossible to simply look into two pails of roof coating and predict whether one product is going to perform better than another does. For this reason, specific guidelines have been established for testing and approval of liquid-applied roof coatings that provide a yardstick that can measure all products. Products that meet specific standards display that information on the label. Facility owners and managers should look for such markings when evaluating a product to meet a specific need. Some markings indicate whether a coating meets specific standards or has the approval of certifying testing organizations.
Among the important standards is American Society for Testing and Materials (ASTM) D 6083. That standard measures the coating tested against specific physical performance and physical characteristics for viscosity, elongation, tensile strength, accelerated weathering after exposure to 1,000 hours of testing, permeance, water swelling, adhesion, tear strength, and low-temperature flexibility. If met, this comprehensive set of standards should lead managers to an excellent product.