Reflective Coatings
Reflective coatings come in a wide variety of paints, membranes, and textures to reflect solar and ultraviolet heat. The use of reflective coating can reduce interior temperatures of a building 7 to 10 degrees and has a life expectancy of ten times that of normal paint. Using reflective coatings will reduce energy needed to cool homes, offices, and shopping centers and reduce carbon dioxide emissions.
Energy star reflective coatings are composed mainly from acrylic or urethane. Reflective coatings should be applied by a certified contractor because they might require special surface preparation, repair of leaks or damaged areas and proper selection of materials.
Reflective Roof Coatings
You can lower cooling costs and extend roof life by putting a light colored coating (also called cool-coating system) over an existing roof. Reflective roof coatings can provide a water tight surface as well as reflecting heat and reducing heat transfer to the inside of the building. This extends the life of HVAC systems and reduces maintenance costs.
Reflective coatings are measured in terms of their albedo. The higher the albedo of a surface, the more heat it reflects and the better its performance in reducing interior temperatures. Built-up roofing such as bitumen and tar and gravel with albedos from 0.1 to 0.20 can absorb almost 80% of the heat they received, transferring the heat to the building’s interior.
Typical coating costs can vary from $0.50 to $1.50 per square foot depending on quality of coating and roof condition. Reflective coatings are categorized by the IRS as restoration, not capital improvement, allowing deduction of its expense in one year instead of amortization over the life of the roof.
Reflective Roof Coating Benefits
The use of reflective coatings on roof surfaces is a simple solution construction professionals can specify to increase building endurance and save money for building owners. Below is a list of possible benefits:
Reduces interior temperature by 7-10 degrees
Applies toward LEED credit
Reduces roof surface temperature by 20 to 60 degrees
Increases effective ‘R’ value
Extends life of HVAC systems
Reduces energy consumption
Can reduce the size of original HVAC design system
Creates a more comfortable interior environment
Can help reduce the ‘urban heat island’ effect
Can be applied over almost any roof surface
Extends life of roofing systems
Easier installation when compare to other alternative surface materials
Reduces the carbon footprint of the building
Wide variety of colors to choose from
The reflectiveness of the coating must be measured by test methods ASTM E424-71, E903-96, C1549-04, E1918-97 or a solar spectrum reflectometer, and have a minimum reflectivity of 75%. The U.S. Department of Energy's Oak Ridge National Laboratory has an online system that will assist you better when evaluating the benefits that you will get when applying reflective coatings. You can calculate reflective coating energy savings and peak demand saving by clicking here.
Reflective Roof Coating Manufacturers
There are many reflective coating manufactures, but here is a small list:
