Is Your Roof Wasting Energy?
Greentips: June 2010
The relatively low up-front cost of asphalt shingles makes them the roofing material of choice for about 70 percent of American homeowners. But asphalt has drawbacks that can end up costing homeowners (and the environment) more in the long run. For example, asphalt shingles absorb 91 percent of the sun’s heat, increasing air conditioning use in the summer, and they wear out more quickly than other roofing materials, resulting in more frequent replacement and more waste—about 11 million tons of worn shingles per year.
A variety of alternatives can help you keep a more eco-friendly roof over your head:
* Slate, clay, and concrete. These traditional materials can last 100 years or more (compared with about 30 years for asphalt shingles), and they also help insulate a house, reducing cooling costs in the summer. On the down side, they’re expensive (up to $1,000 per 100 square feet installed, versus $60 to $350 for asphalt) and heavy (so they require more fuel to transport). Opt for locally salvaged or produced materials if possible.
* Recycled materials. Reclaimed car bumpers, carpeting, and even (according to a couple innovative companies) plastic from disposable diapers can be transformed into shingles that look like real slate, wood, or clay. These materials weigh less, are less expensive than their natural counterparts (about $700 to $900 per 100 square feet installed), and last about 50 years. Metal roofs are also a “green” option, as they typically contain a high percentage of recycled content and are recyclable.
* Energy-efficient additives. Metal, ceramic, and concrete roofs with reflective pigments or coatings can reduce incoming solar radiation by at least 70 percent and air conditioner demand by 15 percent. White and light colors reflect the most solar radiation. These “cool” roofs can be as expensive as slate but can last up to 50 years or more while reducing energy costs. In addition, metal roofs with reflective coatings are eligible for a federal tax credit worth 30 percent of the material cost, up to $1,500 (see the Related Resources).
If asphalt is your only option, reduce its impact by choosing shingles with a longer life span (40 to 50 years versus 15 to 30) and recycled content in the form of waste-paper backing and/or reclaimed minerals. Energy Star-rated reflective asphalt shingles also qualify for a federal tax credit. And ask your installer to recycle your old shingles if possible—many states reclaim the asphalt for use in pavement or new shingles (see the Related Resources).
