Reflective coatings used in pilot program; lower utility bills also a goal
By Reginald Fields
Originally published July 9, 2003
As hot as it has been outdoors, it has been downright sweltering on the second floor of Rose Smith's West Baltimore rowhouse.
"Oooh, it gets very warm, too warm in there," said Smith, standing outside her West Forest Park Avenue home of 40 years.
But as she watches two men scale down a ladder from her flat roof - they look more like painters than roofers, with white paint caked on their arms and uniforms - Smith is dreaming of cooler days.
Her black tar roof now sports a reflective white finish, a radical change from the traditional rowhouse look in Baltimore. If city officials have their way, more homes will undergo a similar makeover.
It's not just another cosmetic fad in the making. The new roofing is designed to make homes cooler and to lower utility bills.
Officials with the city's weatherization program are piloting the cool-roof system at 14 rowhouses, including Smith's, and plan to do 14 more. No firm commitment has been made beyond that point, said Dave Brosch, chief inspector with the program, which is run by the Department of Housing.
It's a change from the usual work of the program, which helps low-income families complete repairs they couldn't otherwise afford. But it's consistent with the program's purpose.
"It could make a real difference for people who don't have a lot of disposable income," Brosch said. "And that's the clientele that we are serving here."
The cool-roof system is used in Philadelphia neighborhoods and in several cities between here and California, where it is most popular. It is typically found on commercial buildings.
The idea is simple: White roofs reflect sunlight and emit heat better than darker ones.
The roof system does not work with shingled roofs, only with flat or slightly sloped tar and asphalt or metal roofs, those typically found on Baltimore rowhouses. Two materials are used: a white, single-ply plastic material or an acrylic-based coating that is thicker than paint.
In Philadelphia, workers apply the acrylic coating over existing roofs. In Baltimore, Brosch hired a Philadelphia company, Roof Menders Inc., to apply a meshlike underlay for extra waterproofing and then the acrylic material.
The cool-roof industry is rapidly changing as companies experiment to find the material that is most reflective, durable and cost-effective.
In Baltimore, the roofs cost $3.50 to $4 a square foot, said Miriam Cunningham of Roof Menders. The city is paying the bill for the 28 residents, Brosch said.
Most of the cool-roof materials used have been around for less than five years, and it is unclear whether they will fulfill the long-range guarantees manufacturers are promising.
The cool-roof system is catching on, said Audrey Chang, of the Cool Roof Rating Council in Oakland, Calif., a trade organization for dozens of companies that apply the roofs nationwide.
In areas such as business districts or residential neighborhoods, where cool roofs have been installed, the outside temperature in the immediate area is cooler than in areas a block away without the roofs, Chang said.
But there are drawbacks.
The cool roofs deflect heat not only in hot weather, but also when it's cold and more warmth is wanted.
And the system is more expensive than applying a tar roof, although proponents say the cost can be made up with lower maintenance and utility bills over several years.
White roofs last about a decade and are less effective when they are dirty. They also are ineffective if the house or building is poorly insulated.
"Even if you have a cool roof," Chang said, "if you don't have good insulation in your walls and roof, then it won't help. It has to be an integrated approach."
Brosch said it might be several years before the cool roofs are widely used in Baltimore, if it happens at all, because so little is known about the roofs and because his agency would have to attract additional funding to offer it to weatherization program clients.
Other city officials will need to be convinced that the system is worthwhile, Brosch said.
He has a fan in Smith, who can hardly imagine her home without water-stained ceilings and walls from her old leaky roof, or feeling a bit more comfortable on a hot summer day.
"This is wonderful," she said. "I'm looking forward to no leaks and being a little cooler when I'm sitting in my house."
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