DARK ROOFS AND COOLING COSTS
Dark roofs are striking and are becoming increasingly popular. Despite their curb appeal, we still hear concerns from customers about darker roofs affecting their air-conditioning costs in the summer.
It is true that darker-colored shingles get warmer than lighter-colored shingles. A completely black shingle will increase the attic temperature by about 8-10 degrees, when compared to a completely white shingle. However, when it comes to the grays, browns, and tans, choosing a black shingle will only increase the attic temperature by about 2-3 degrees.
What’s most important to keep in mind, however, is that even an 8-10 degree difference in your attic temperature will not necessarily increase the temperature of your living space. In fact, for traditionally constructed homes, the temperature of the shingle has virtually NO effect on your air conditioning use.
Why? Most homes have an attic and on the attic floor, a layer of insulation. Insulation works by trapping air in bulky, lightweight material and air is a poor conductor of heat. Therefore, insulation slows the transfer of heat from one area (your attic) to another (your living space). In addition to the effects of insulation, attics also tend to be well-vented, further reducing the transfer of the heat from the roof into your living space.
We recommend that you choose a shingle color that best compliments your home, rather than choosing one based on how it will affect your attic temperature. If you have proper ventilation and insulation, the color should have no effect!