Three Benefits to Cool “Green” Roofs

Green roofs are literally, the cool new thing in roofing technology. Not only do you reduce your carbon footprint by installing one of these roof systems, but you actually keep your roof cool!  Many commercial buildings are using green roof systems to protect their roofs from sunlight, reducing toxins that may be contained in the run off from storm waters, decreasing emissions from heated roofing materials and of course, keeping their roofs cooler.

First, let’s explore the definition of a cool roof system. A cool roof system is usually made up of materials that will reflect the suns energy. You could use a light colored paint, light colored roof tiles, single ply rubber membrane or light colored shingles. You will find lots of white roofing in Bermuda for example where the sun can be brutal!

Green roofs consist of several layers, just like your typical garden bed. First there is a waterproof membrane. To that you will need to add a drainage system, growing medium and of course, the plants!

There are two types of green roofs. Extensive and intensive. Extensive roofs use plants that will stand up to a drought or other extreme conditions. These plants don’t need a lot of attention or supplements. Intensive green roofs are set up more like a garden or a park, where things are planted purposefully, and any type of plant may be used. Can you guess which type is more expensive and needs more care?

According to the EPA, the three major benefits to a cool roof are:

1. Lower energy use.  There is less heat transferred from the roof to the home, therefore, you spend less energy and dollars cooling your quarters. (In a green roof, the plants absorb most of the sun’s energy)

2. A cool roof reduces pollution and emissions by lowering energy use, (a green roof will also reduce your footprint by eliminating the potentially toxic off-gassing from heated roof materials.)

3. Health and comfort. This really can’t be measured in dollars can it?  Looking back at the previous two points, reducing the air temperature, reducing the amount of time that you have to run an air conditioner, decreases the likelihood of heat related illness, and let’s face it, reduce your stress when it comes to how much money you are spending to stay cool!