By Curtis Liscum
Depending on a building’s size, location, amount of thermal insulation, and energy costs, a reflective coating can provide energy savings by reducing a building’s cooling loads. While each building obviously is different, a typical building located in a southern climate with large enough roof area and minimal amounts of insulation will generate energy savings. in many cases, these savings can be sufficient to pay back the coating installation cost in five to seven years.
Weighing the Options
Elastomeric coatings seem to encompass an even wider variety of base materials than bituminous coatings. Base materials include latex, acrylic, Hypalon, neoprene, silicone, urethane, and hybrid materials.
Manufacturers regularly introduce new types of coatings. Elastomeric coatings are compatible with most types of roof systems, but managers use them most on single-ply systems, spray-applied polyurethane foam, and metal roofs. Managers also can specify elastomeric coatings for use on most built-up and modified bitumen systems.
Matching Coatings and Needs
Selecting the appropriate coating product requires research into available products offered in the area, their advantages and disadvantages, potential energy savings, their compatibility with the roofing system to be coated. Nothing is more discouraging than watching a coating – and energy savings – flake off after a few short months because the coating was not compatible with the roof.
Adhesion is paramount. Coatings that do not adhere to the roof will not perform. Reflective is the method by which the coating provides energy savings. If the reflectivity fades, so goes the energy savings. The ability to withstand anticipated events is important to coating longevity.
One final thing managers need to consider in selecting a roof coating is compliance with regulations governing volatile organic compounds(VOC). Most coatings are manufactured with solvents. Depending on the building’s location and the applicable VOC-compliant coating might be required.
As energy costs rise, more managers will look to coatings as one way to decrease cooling loads and reduce energy costs. Proven performance is the key to a good coating, and the only way to truly verify performance is to visit similar local projects.
Coating manufacturers whose products comply with the provisions of the Energy Star program are good starting points in selecting a coating that can reduce peak cooling demand by 10-15 percent.
*Curtis L. Liscum, RRC – is a Registered Roof Consultant and senior consultant with Benchmark Inc. – a nationwide roof and pavement consulting firm based in Cedar Rapids, Iowa. He has more than 20 years of experience as a roof consultant.