Cool roofs are roofs consisting of materials that reflect the sun’s energy from the roof surface, and are generally white in color, though non-white colors are starting to become available. They can reduce the roof’s surface temperature by up to 100 degrees Fahrenheit, which also reduces the heat transferred into the building below.
As you can imagine, cool roofs have many benefits:
- Save on your annual electricity bills by reducing summer air conditioning costs.
- Save peak electricity demand costs if you have time-of-use metering.
- Extend the life of your roof, reducing roof maintenance and replacement expenses.
- Improve human health and comfort indoors during the summer.
- Reduce the “heat island effect” in cities and suburbs.
- Reduce air pollution and greenhouse gas emissions.
- Reduce roofing waste added to landfills.
This all sounds great, doesn’t it? Now you have to decide what kind is best for your residential or commercial building. Different cool roof programs and materials work better for lower-sloped roofs or steep-sloped roofs.
Low-sloped cool roofs
- Cool roof coatings: we discussed roof coatings recently; they are surface treatments that are best applied to low-sloped roofs in good condition. They contain additives that improve adhesion, durability, and have the ability to shed dirt under normal rainfall. Cool coatings can be applied to a wide range of surfaces including asphalt capsheet, gravel, metal and various single-ply materials.
- Single-ply membranes: single-ply membranes come in a pre-fabricated sheet that is applied in a single layer to the roof. The materials are glued or mechanically fastened in place over the entire roof with seams sealed.
Cool roof coatings are generally used if an existing roof needs only moderate repair, and single-ply membranes are used for more extensive repairs.
Steep-sloped cool roofs
The market for steep-sloped cool roofing materials is growing, although the solar reflectance for these products is generally lower. A number of products are available for tiles and painted metal roofing. Many manufacturers have begun producing “cool colored” tiles that contain pigments that reflect solar energy. These tiles come in traditional colors and are long-lasting and durable.
If you are interested in exploring your cool roof options, contact Showalter!
Courtesy of Consumer Energy Center and the EPA