If you have asphalt shingle roofing and you live in an area that frequently experiences a lot of hot, sunny weather, you may be considering painting your roof white or another light color.
This helps reflect the sun’s rays so that they aren’t absorbed into your roof — and ultimately into your home. Homes with roofs with dark asphalt shingles can get significantly hotter than homes with light-colored shingles or other roofing materials.
How much hotter? On a sunny day with an outside temperature of 83 degrees F, a thermometer gun was used to measure the surface temperature of a cedar colored asphalt shingle and another that had been painted white.
The brown shingle reached a temperature of 173 degrees F, while the white shingle measured 128 degrees F. Both are very hot, but the white shingle was 44 degrees F cooler than the darker colored one.
Lighter Roofs Are Significantly Cooler
Not all of this heat is absorbed into the home, obviously. But this little experiment proves that lighter colored roofing can make a big temperature difference in your home on hot, sunny days. Some estimates say you could save between 10% and 15% off your home cooling costs with a light colored roof.
But the problem with painting your roofing materials is finding a paint that will adhere to asphalt shingles. The kind of exterior latex paint you would use to paint your home’s outside walls usually will begin to flake off of a shingle roof after only a couple of weeks.
In contrast, the same paint used on light-colored metal roofing panels can last about 30 years or even longer.
Two Options for a Cooler Home
So painting your asphalt roofing isn’t the solution. To reduce the temperature in your home and reduce your cooling costs, a better plan is to replace your shingle roofing with metal roofing panels that can be painted a lighter color.
Another option is to install a radiant barrier above your roof deck. With a radiant barrier, the color of the roof doesn’t have as much effect on the temperature of your home.