For a long time, most people associated the roof with protection from the elements, as well as with the curb appeal of their home. The thought that your roof had anything to do with energy efficiency, or that improving the energy efficiency of your roof could extend its life was something that most people never considered. Times have changed, however, and a recent trend in roofing has many people moving toward cool roofs. While most beneficial to those who live in warmer climates, a cool roof can benefit nearly everyone both in energy efficiency and in the durability of the roof itself.
What Is a Cool Roof?
The term “cool roof” comes from the fact that the roofing material doesn’t become superheated during the warmer months of the year. Because the roof is at the top of the home, it receives the full brunt of the sun’s rays from above. And because the area just below the roof tends to be a collecting area for heat rising up from within the house, this heat transfer between the roof and the attic space can result in higher energy bills as the air conditioner works to cool the home and a faster deterioration of the roofing shingles as they become superheated.
In a cool roof, multiple things are taking place to prevent this cycle from happening. First, the roof itself reflects the UV rays from the sun, allowing them to bounce off rather than soaking them in. This is through the use of unusually thick layers of white or special reflective paint roof colors or solar-reflective granules in asphalt shingles. In effect, this both keeps the roof cooler, and helps prevent some of the deterioration that can occur.
Next, the space beneath the roof is insulated to help prevent heat transfer both down from the roof into the home below, and from the attic up onto the roof. While many people do insulate their attic spaces, it’s insulation of the roof deck that’s particularly important in this case. If the roof deck is insulated from below, then heat from the attic can’t transfer back up to the roof, and a heat from the sun can’t make its way back down into your home. This helps keep both your roof and the rest of your home cooler year-round.
Finally, attic ventilation is added, which keeps air circulating throughout the space beneath the roof. This ventilation is important because it prevents heat build-up both on the roof and in the attic. This in turns means there is less heat to be transferred down into your living area and up onto the roof.
Benefits of a Cool Roof
The number one benefit of a cool roof is a cooler home and the lower energy bills that go along with it. When your roof isn’t being superheated by the sun and attic below, it isn’t transferring that heat down into your living area. This means that your home is more comfortable to live in, and your HVAC system doesn’t have to work as hard.
The second benefit of a cooler roof occurs during the winter months. Most people aren’t aware of the fact that a warm roof in winter could result in things like ice dams and leaks. Snow collecting on a warm roof will melt and run down to the edge of the home. The melting snow then hits a colder area on the eaves and refreezes, causing an ice dam. Over time, this ice dam could force water back up underneath your shingles, where it infiltrates your home as a leak. If this happens frequently enough, it can also cause your shingles to deteriorate. A cool roof doesn’t transfer heat from the attic up to the roof, which means that your snow won’t melt, collect, refreeze, and cause those leaks.
Finally, a cool roof may last longer than a traditional roof. This is because the UV rays from the sun are responsible for some of the deterioration of the roofing shingles. If the UV rays are bouncing off the shingled roof, then they aren’t causing it to break down.
A superheated attic or roof can also cause shingle deterioration; cool roofs prevent this heat transfer, which helps stop shingle deterioration this way as well. Finally, a cool roof will experience fewer leaks due to ice dams. This not only helps prevent further shingle damage, it also helps prevent things like water damage, mold, and mildew growth inside your home.
Cool roofs that are properly ventilated also experience less moisture in the attic area during the winter months. This lack of moisture means less condensation and humidity, and therefore less of a chance of mold or mildew growth occurring in your attic.
Invest in a Cool Roof
If it’s time to get a new roof for your home, consider getting a cool roof. Dimensional or 3-tab shingles will sure look nice but a cool roof is wallet-friendly in the long run. From solar-reflective shingles, which reflect UV rays to additional insulation and ventilation, a cool roof can pay for itself with lower energy bills and fewer repairs over time. Invest in a cool roof for your home to reap the benefits for yourself.