October 2005

Hurricane Roof Damage Might be an Opportunity for an
Energy-Saving Roof


Last summer's hurricanes in Florida left many of the state's homes decorated with blue tarps on their roofs. As a result, many homeowners have had roofs repaired or replaced since then, but the numbers of tarps still visible says that lots of roofs still need work.

The good news is that the unfortunate situation of needing to replace a roof can be turned into a money-saving opportunity. Choosing the right roof can give you a cooler, more energy-efficient home and save money on your monthly utility bills.

For the past few years, FSEC researchers have been monitoring and collecting roof and attic temperature data on a number of homes around the state, including a shingle-roof house in Cocoa. The house sustained a considerable amount of roof damage last year from hurricanes Frances and Jeanne and although most of the roof was left intact, there was enough damage to warrant replacement.

After seeing the benefits of metal roofs in FSEC's research, the homeowner decided to retrofit his house with a white metal roof. As a result, the homeowner got an energy-efficient roof and FSEC researchers got a classic before-and-after study with data on the old shingle roof and now data on the new metal one. Data continues to be collected on the Cocoa home and a comparison of the performance of the old shingle roof and the new metal roof is available online at http://www.baihp.org/casestud/hdh_roof/index.htm.

The initial findings indicate a 19% cooling cost savings since the metal roof was installed, a number that is on-target with FSEC's prior research. See http://www.fsec.ucf.edu/en/publications/html/FSEC-CR-1220-00/index.htm for a comprehensive study that was conducted in 2002 comparing seven side-by-side homes in Ft. Myers with various roofing configurations.

FSEC buildings researcher Danny Parker, who has been actively involved in researching roof performance for many years, notes that "FSEC research spanning the last decade has clearly shown that a white reflective tile or a white metal roof can reduce space cooling by 20% or more." A cooler attic means a cooler house, and a white reflective roof is shown to make a substantial difference.

"Tests performed by FSEC show the temperature in attics covered by dark shingle roofs can reach as high as 140 degrees on summer days," Parker says. "Meanwhile, a white metal or white tile roof never gets much hotter than the outside temperature, with light colored tile or metal registering somewhere in between."

Although a white reflective roof may not be a preferred choice for some people for aesthetic reasons, the energy-saving benefits may outweigh the objections. And in addition to keeping a house much cooler, a white metal or white tile roof typically lasts at least twice as long as a shingle roof.

In addition to a noticeably lower electric bill, the homeowner says there is another immediate advantage he likes: lower attic temperatures have made it less of a bother to retrieve holiday decorations and other things stored in the attic. He also says that "I now have great satisfaction in knowing that when the next big storm comes our way and we're without power and air conditioning for some time, we'll be much cooler because there's not as much heat getting into the house from the attic."

Obviously, one big factor in a situation like this is the cost. Replacing the roof of this home with shingles was estimated at $7,750 plus labor (an additional $4,200, which included removing the original shingles). Meanwhile, the cost of the metal roof was actually cheaper for the materials ($7,400). The homeowner did not get labor costs for the metal roof since he did the work himself, but he estimates that would have been around $6,000 to have it done. The difference of around $1,500 extra for the materials and installation of a metal roof would be repaid over time by the energy savings.

This has been one area of study where the research has been very clear. Choosing a light-colored metal roof can pay back big dividends in energy savings and in indoor comfort. If your house needs its roof replaced, you might use these studies to turn the situation into an opportunity to save energy and money.