Home Repair And Improvement: Keeping Cool With Insulation And Ventilation

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• Just Like Clothing, Light-Colored Roofs Keep Homes Cool

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  When people choose clothes to wear in the summer, they often opt for lighter colors because they know that reflecting the Sun will keep them cooler. There a similar effect with houses, experts say.

  “We always recommend, if you’re looking for a roof color, to go with a slightly lighter color,” said Ken Adams, the owner of Adams Design Construction in Madison. “It’s going to reflect some of the heat out in the summer and keep the roof a little cooler.”

  Adams added that the lighter color can actually increase the life of the roof as well. He estimates that a hot roof might have a life that is 10 percent shorter than a roof that stays cool more efficiently. He said that it only take a few degrees either way to make a difference over time.

  The same principle comes into play when choosing siding, he said.

  “If you’re trying to reduce the amount of solar gain, which is the amount of heat that’s being sucked into the building in the summertime, lighter colors are always better,” Adams said.

  The process of reflection by lighter colors is called the Albedo effect, according to John Freiburger, a Wisconsin-registered home inspector who specializes in the evaluation of older structures andthe founder of Freiburger and Associates in Fitchburg. Albedo comes from “alba,” which means white in Latin.

  Use of the Albedo effect is part of the cool roof movement. According to the U.S. Department of Energy downloadable fact sheet on cool roofs, they can “reduce by up to 15 percent the annual air-conditioning energy use of a single-story building.” In addition, a roof with good reflective qualities can also make homes without air conditioning much more comfortable.

  Freiburg pointed out that while Wisconsin hasn’t had a very hot summer this year, June was the warmest month globally on record. So, finding ways to keep buildings comfortable while minimizing energy usage will continue to grow as a priority.

  Freiburger said that the black rubber roofs that have been used commonly for years absorb a lot of heat, but newer options include thermal plastics and white EPDM roofs. According to the EPDM roofing association, it is “an extremely durable synthetic rubber roofing membrane (ethylene propylene diene terpolymer) widely used in low-slope buildings in the (U.S.) and worldwide.”

  If a white roof seems strange, Adams advised consumers not to worry. Even choosing a lighter shade of brown over a darker shade will make a difference. He added that on a flat roof, which most people won’t be seeing once it’s installed, white can be a great choice.