A metal roof with a light-colored or reflective “cool” finish can keep the roof much cooler in summer sun, which can lower air conditioning demand. The U.S. Department of Energy says a reflective roof can stay more than 50°F cooler than a conventional roof. Dark or unpainted metal doesn’t get the same benefit.
Color and finish matter most
Energy savings come from how much sunlight the roof reflects and how well it releases heat. According to the Department of Energy, unpainted metal reflects sunlight well but holds onto heat, so it can get hotter than painted metal of the same reflectance. Factory-painted metal in a light or “cool” color performs best.
What else affects your cooling bill
- Attic insulation and ventilation.
- The age and efficiency of your AC system.
- Shade from trees.
- Air leaks into the attic.
Because of all these factors, the savings for any one home vary, and we won’t promise a specific number. In Memphis, where summers are long and hot, a reflective roof is one of several ways to keep an attic cooler.
Ask about the finish
If energy savings matter to you, ask for a cool-rated color and the finish’s solar reflectance rating, and have the attic ventilation checked at the same time.
By the numbers
- Conventional roofs can reach 150°F or more on a sunny summer afternoon (U.S. Department of Energy).
- A reflective roof under the same conditions can stay more than 50°F cooler (U.S. Department of Energy).
- Unpainted metal can run hotter than painted metal of the same solar reflectance (U.S. Department of Energy).
Thinking about metal for your home? Schedule a roof inspection or call (901) 834-7663, and we’ll tell you whether metal makes sense for your roof.
