Beyond cosmetics: how your choice of roofing material can affect your energy bills.
Contrary to popular belief, all roofs aren’t created equal. Around the world, builders use dozens of different materials to keep the elements out of homes and businesses. These materials are generally selected for their “fit” with the local climate, so roofs in warm, dry places look very different from roofs in cool, wet areas. In Portland, some of the most common roofing materials include metal, shingle and tile. Each of these materials has its own benefits and drawbacks for energy-conscious homeowners and business owners.
Once virtually unknown in the Pacific Northwest, light-colored metal roofs are an increasingly popular choice for local homeowners. During the summer, these “cool roofs” can reduce energy absorption by as much as 25% relative to asphalt roofs. This is due to their high albedo effect, a measure of how well they reflect solar energy back into the atmosphere without absorbing it. Although light-colored metal roofs don’t absorb energy as well during the winter, Portland’s climate isn’t severe enough for this to make much of a difference on users’ heating bills. Additionally, the region’s near-constant winter cloud cover reduces the efficacy of sunlight as a home-heating booster.
Although asphalt shingle roofs can boost energy absorption during the winter, they’re often regarded as a subpar choice for homeowners who want to keep cool during the summer. In fact, they only reflect 10% to 15% of the energy that touches them. However, high-tech coatings and many single-ply membranes can help low slope roofs reflect heat on the hottest days. Additionally, attic insulation can dramatically improve cooling efficacy during the warm season.
Tile roofs are popular in hot, dry places like Phoenix and Las Vegas, but Portland’s climate isn’t ideal for this material. Tile tends to be a poor insulator and has trouble keeping homes warm in the absence of effective insulation. In addition, it’s also prone to leaks—a major drawback in Portland’s wet climate. However, light-colored tiles are adept at reflecting solar radiation during the height of summer.
How Does Slope Affect Efficiency?
Material isn’t the only factor that affects roof efficiency. A roof’s slope is a major determinant of its overall energy rating. Since the sun strikes them at an indirect angle during the warmest part of the day, steep-sloped roofs are ideal for homeowners who worry about air conditioning costs. By contrast, low-sloped roofs are less intrinsically efficient. However, it’s easier to apply coatings or other radiation-shunting materials to these designs.
Find Energy Efficient Roofing in Portland
No matter which material you decide to use in your home’s roof, you’ll need to make sure it’s installed promptly and effectively. At Interstate Roofing, we’re proud to offer a range of roofing choices and provide the assistance that you need to enjoy years of superior performance. To learn more about all of our roofing products and services, call us at 503-684-5611 or contact.