If you're not planning on replacing your roof anytime soon (for example, if you have a metal roof that's expected to last another 45 years), you may wonder what you can do to improve its eco-friendly properties and save on cooling bills. Never fear; there are a number of things you can do to an existing roof to make it cooler and more earth-friendly. Here are four options, some non-invasive and some more complex, that can transform your current roof into a more eco-friendly one.
1. Paint and cool roof coatings
Because lighter colors reflect more light and absorb less, simply changing the color of your roof can reduce the amount of energy you spend on cooling during the summer. Bright white is considered the best color. Metal roofs are an ideal candidate for this, but you can also paint other roofing materials, such as tile or wood shakes. A specially developed type of coating called a "cool roof" coating is available as well. This is an alternative to paint that helps the roof reflect not only the sun's light but also its heat.
2. Rooftop garden
Installing a rooftop garden, also known as a "green roof" due to the plants' greenery, is one of the best things you can do for your roof. It doesn't necessarily require a roof replacement, although it may require reinforcement if the installation includes a large amount of soil. The benefits of having plants covering your roof are not limited to cooling. The plants also insulate the roof in winter, help manage storm water, and use the sunlight that hits them to convert carbon dioxide into oxygen rather than simply deflecting it. Rooftop gardens work best on flat roofs, but if you have a slightly sloped roof, you can still have a version of a "green roof" that uses dense mats of plants clinging tightly to the surface of your roof.
Shading part of your roof strategically can reduce a lot of the heat buildup incurred by direct sunlight. You can simply plant a fast-growing tree relatively near to your house at such an angle that it will eventually provide shade during the hot part of the day in summer. The downsides to this plan are that it will be several years before the tree provides any shade and that planting a tree near your house is a risk because it can fall in a storm or allow debris to fall on your roof and clog your gutters.
4. Solar panels
Although solar panels are still a considerable investment, they're much more cost-effective than they were a few years ago. Placing solar panels on your roof will not necessarily cool the entire roof, but the panels do help provide shade to the areas they cover and insulation in the winter as well. Of course, they also provide energy to help offset any heat that the roof accrues.