Many environmentalists define ‘green roofs’ as those that nurture growing plants. However, Rebecca Fairley Raney reports on home.howstuffworks.com that growing plants on a roof does not, by itself, make the roof cool; rather, an environmentally-friendly roof is one that has excellent cooling properties.

Technically speaking, the term “green roof” applies to a roof upon which living plants have been planted and nurtured.

Oddly enough, though, this style of green roof isn’t a cool roof. And to be really eco-friendly, you want your roof to be cool. So here’s another way to look at it. Some of the great producers of the greenhouse effect are the roofs over our heads. The sun hits the roof, and the roof reflects light back into the atmosphere. The intensity and angle of that reflected light create the so-called “heat island” effect in cities and can erode the atmosphere. Further, if the roofing material doesn’t have insulating properties, it can create a secondary environmental issue by requiring the inhabitants of the building to crank up the climate control.

So to be green, you have to be cool.

Fairley then goes on to list 10 options for a cool roof – some of which are traditional roofing materials found in many homes today, while others are, in fact, installation processes that keep a roof cool. The ability to cool a home is an especially ideal Palo Alto roofing quality because of the inherently warm climate in the area, as in other parts of California such as Menlo Park and Sunnyvale. Ms. Fairley says that an eco-friendly roof is one that can resist and/or reflect harsh sunlight, has great insulating abilities, and is recyclable.

Tile roofing and coated metal roofing are two common materials that can effectively cool a house; other materials like single-ply roofing, roof pavers, and tar may not be commonly used in residential houses but also offer excellent cooling qualities. Shakes and shingles, which are the most common roofing materials in the country, are also the least cool; but treating them with reflective pigments and painting them with light colors can improve their cooling ability by making them more light-reflective. To identify the right kind of green roof for your home, it is best to tap the expertise of a reputable roofing company in Palo Alto – such as Shelton Roofing, for instance – that has considerable experience in setting up eco-friendly roofs.

(Info from Top 10 Green Roofing Options, home.howstuffworks.com)