An October 15 Baltimore Sun B’More Green blog post discusses the findings of an Abell Foundation report on the benefits of “cool roofs” in Baltimore City.
A new report by the Abell Foundation suggests white or cool roof systems like hers could help fight global climate change while also making the city a healthier place to live — and urged local and state governments to do more to expand installation efforts. …
Ideal for flat or gently sloping surfaces, cool roofs involve more than slathering a coat of white or shiny metallic paint on an existing layer of tar. They come in two basic types, both intended to reflect sunlight and keep the building below from heating up as much. One involves applying a liquid acrylic coating that dries into a rubber-like surface, while the other features a thin membrane laid down over the roof to seal it.
They can reflect up to 80 percent of sunlight they receive, the report says. Studies show they can cut air-conditioning costs by up to 20 percent and even lower indoor temperatures inside buildings without air conditioning. White or light-colored roofs may reduce the amount of solar heat homes get in winter, but the savings in warm weather more than offset any extra heating needed when it’s cold in all but the northernmost climes, studies show. …
Cool roofs can cost about the same as traditional ones, proponents say. Installation and materials range from $3.90 to $9.50 per square foot, compared with $4 to $8.25 per square foot for an asphalt roof, according to the report. Upkeep on cool roofs also is less, because they don’t heat up and crack as much.
New or existing roofs covered with liquid coatings can easily last a decade, the report said, and two to three times longer with regular recoating every five years. The membrane roof coverings generally require replacement of the existing roof first, but also can last 25 to 30 years with minor maintenance.
The Abell report also recommends that the City require cool roofs on new and renovated buildings, similar to what California has done and that Maryland create a cool roof installation campaign. The post also notes that the Maryland Energy Administration will likely offer financial incentives for cool roof installations.