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It’s summer. A hot and dry one. You’re outside gardening until the heat becomes too much and you head inside to chill, but the heat is radiating down on you, so you turn on the swamp cooler or air conditioner. Then you remember last month’s electric bill and you turn the coolers off and look for a fan that uses less electricity, and you wonder, “Isn’t there a better way to live?”
Yes there is! It’s as easy as painting your roof white, but not with off-the-shelf house paint! According to local independent contractor John Grisak, there are over 1,000 products available to turn your roof white, and many have added benefits of sealing your roof tightly against rain for up to 15 years. And if you have solar collectors, a white roof will increase the amount of sunlight hitting them, and you can receive a federal tax credit at the same time.
But I’m getting ahead of myself. Painting your roof white to cool your house is not a heat-induced fantasy but a booming business that has caught the imagination and budget of government agencies and cities like New York, which claims to have cooled 3,671,000 square feet of city roofs in its effort to reduce the oppressive “heat island” effect of so many concrete roadways and black-tar roofs radiating mega-degrees of heat upwards.
This solution has been around since at least the 1990s, and it’s been an effective way for some cities to attack the urban heat-island problem by covering flat roofs with white liquid-applied membrane roof coatings that can cut roof temperatures from 60 to 100 degrees Fahrenheit. That’s a lot of heat reflected back upwards before it can creep down into your granulated tar-paper covering, into the plaster or wallboard of your interior ceilings and down on your head, reducing the electricity needed to run your air conditioner in the summer by as much as 30 percent.
The federal government’s ENERGY STAR program offers tax credits of 10 percent of the cost of approved cool roof materials up to a maximum of $500. To evaluate and rate the various products on the market, there is the nonprofit Cool Roof Rating Council, made up of industry experts as well as officials from the California Energy Commission. Arizona has established its own Cool Roof Council to promote and educate homeowners and contractors about this very effective practice.
So what about New Mexico? John Grisak tells me that El Paso has bitten the apple. Log on to GoogleEarth, hover and take a look, but wear dark glasses so you’re not blinded by the light reflecting back up at you! Okay, now remove those dark glasses and travel up to Albuquerque, where there are several commercial buildings and a few residential buildings with whiter roofs, but overall a small minority. Now go up to Santa Fe—and weep. Virtually none.
But other than that, it’s hit or miss around the state. Granted, we don’t have any heat islands that can compete with Phoenix (thank goodness), but Albuquerque has a mega-load of flat roofs, and even one flat roof (yours?) can reflect tons of heat back skyward.
Neither Bernalillo County nor Santa Fe County has a public outreach program on cool-roof initiatives. The city of Albuquerque uses a menu of options homeowners can select from to qualify for their green building/green path program, but no cool-roof initiatives, per se. NM’s big power utility, PNM, has the federal ENERGY STAR program and tax credit page on its website, but other than that, no specific program promoting making your roof white.
In the city of Santa Fe, while certain areas of the city have color restrictions on roofing to satisfy aesthetic or historic concerns, the majority of the city does not have such restrictions, so there’s a lot of potential cooling effect there. But discussion of color restrictions for your flat roof in historic districts or covenant-controlled homeowner association developments brings up an interesting note. While white roofs are usually rated as the most reflective, there are several other colors of reflective roofing membranes available. Of the hundreds of cool roof membrane products and suppliers on the market, I randomly picked one company—Kemper System—that offers six colors of reflective membranes, including white. I’ve listed their reflectivity ratings for comparison:
Cool Mint 72%
Cool Adobe 75%
Cool Frost 71%
Cool Steel 63%
Cool Earth 70%
Cool White 74%
Another supplier, LaPolla Industries, offers Thermo-Flex white coating and claims 86 percent reflectivity. Shop around. The point being made here of course is that your cool roof doesn’t have to be white to give you some relief. You can take that to your Homeowners Association or Historic District bureaucrats and have a good argument.
So, who to go to for more information on beating the rapidly increasing heat of NM’s new climate? Given the hit-or-miss nature of finding information on the merits of going white—or reflective—and the fact that there is no listing of contractors in NM who have a verifiable track record in applying the best environmentally compatible reflective coatings, New Mexicans could use a cool-roof information clearinghouse. Surely no more than a one-person office, such a service could be created and supported by a small gaggle of suppliers, contractors and government energy efficiency gurus.
But what does it cost to have 60-100 degrees of heat reflected away from your rooftop, and one ton of heat trapping, atmospheric CO2 offset by every 1,000 square feet of white roof? Getting back to John Grisak for some figures, I find that he charges anywhere from $2 per square foot to $4 per square foot, depending upon the degree of surface preparation necessary. So a 2,500-square-foot roof would cost from $5,000 to 10,000, minus the tax credit—not a small investment. But John says his experience with this process shows him that a white liquid-applied membrane coating will last 15 years, not only reflecting heat but also tightly sealing the roof against leaks. And, if you reapply the top layer of coating (it’s applied in layers) at the 10-year mark (at 1/4th of the original cost), the roof is good for another 10 years. And, he says the roofing membrane he uses is water-based (no solvents), has a 600-psi strength that resists hail and fixes the problem of ponding, which is the cause of most roof failures.
I asked John how NM compares to Houston, where he has worked before, and he said: “While the only flat roofs in Houston are commercial roofs, they get it, and white commercial roofs abound. But in NM, cool roofing seems to be a closely held secret. I’m also an insurance adjustor, and I’ve been on a lot on NM roofs and believe me, they’re all the old heat-absorbing black roofs, where temperatures reach 160-170 degrees. It’s crazy that the white roof alternative hasn’t been promoted more here.”
Earl James is a nonprofit development consultant living near Santa Fe. Contact info and information on his award-winning novel: Bella Coola: The Rainforest Brought Them Home, which recently won a 2013 Nautilus Silver book award, is available at www.earldjames.com
DOE’s Energy Star Program: http://www.energystar.gov/index.cfm?c=tax_credits.tx_index).
Article on Lawrence Berkeley Laboratory study: http://www.ens-newswire.com/ens/sep2008/2008-09-23-01.asp
Cool Roof Rating Council: (http://www.coolroofs.org/)
Arizona Cool Roof Council: http://www.azcoolroof.com/
Albuquerque’s Green Path Program: www.cabq.gov/planning/documents/GreenPathApplicationCriteriaIncentives2011112911.pdf
LaPolla Industries Thermo-Flex: http://www.lapolla.com/images/map/_THTD11.pdf
John Grisak: www.fixthisflatroof.com
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