What is a Cool Roof? Usually light in color, a cool roof reflects the sun’s heat rather than absorbing it, as dark roofs do. It creates the same effect as wearing light colored clothing to keep you cooler in the summer when dark colors make you hotter. White surfaces reflect more than half of the solar radiation while dark surfaces absorb most of it. There are a number of advantages to a cool roof.


Comfort: A cool roof can keep your house as much as 25 degrees cooler than a dark-colored roof – that’s a significant advantage, particularly if your home does not have air conditioning or if there is inadequate insulation on the roof envelop. On a sunny day, the temperature in a house with a cool roof usually increases 20-25 degrees, compared to an increase of 50 degrees for a house with a conventional dark roof.


Savings: A cool roof can reduce your energy consumption costs by as much as 7-15%, representing a significant cost savings – particularly if you live in a hot climate. In addition, cool roofs last longer than conventional roofs, so you will need to replace it less frequently. Cool roofs also place fewer demands on the air conditioner, so it will last longer. If you do have to replace your air conditioner, you can get a smaller unit. Some areas of the country also provide tax savings or rebates for cool roofs.


Greener Home: Not only do cool roofs decrease your energy consumption, but they also reduce your carbon footprint by using fewer fossil fuels and decreasing air pollution. If you live in a city, a cool roof will also help reduce the heat island effect.


Choosing a Cool Roof: The coolness of a cool roof is measured in two ways: by solar reflectance and by thermal emission, both measured on a scale of 0 to 1. Whatever kind of material you choose for your roof, you should look for something with a high value in both categories.


Cool Roof Materials: Almost any kind of material can be cool if it is light colored and reflective, but some are better than others. White vinyl is one of the most effective and popular cool roof options. Metal roofs can be molded into a variety of shapes so they can resemble shingles or other materials. Metal roofs can also have a special coating applied which allows darker colors to achieve the same reflective properties as lighter colors. Clay and concrete tiles are also good for cool roof uses. If you want your existing roof to be cooler, you can get special coatings which you can apply to the roof – or they can be applied in a factory when the material is created.