Look Out! Energy Savings Overhead!

Rincon Congregational Church (Tucson, Ariz.)

Energy-efficient metal roofing is especially attractive to church building committees because it helps keep energy costs down, translating to lower utility bills.

Metal roofs can be constructed on just about any building type -- new or old -- and even seemingly flat roofs can be metal. (In these cases, the metal roof is built at a very low slope to keep the water running off the building.)

Metal can also be put on top of many existing roof structures. A metal roof can usually be placed right on top of an existing roof; the old roof doesn’t even need to be removed. A metal roof constructed on top of an older built-up roof (BUR) is generally less costly than a new BUR, and construction can go on without any interruption to the activities inside the building.

Rincon Congregational Church is a small, 7,000-square-foot church located in Tucson, Ariz. Originally built in 1968 with a BUR, church leaders later had a white spray-on foam applied to the roof. They wanted a new roof that would be long-lasting in Tucson’s heat, provide energy efficiency, and offer a long-term warranty. A standing-seam metal roof met all these criteria, and its modern look has substantially enhanced the facility’s appearance.

Economical and Durable

For a trained work crew, metal roofs can be installed quickly and in less time than other roof types, saving time and money. In May 2003, for example, Tennessee’s East Jackson Church of Christ was destroyed by a tornado. A new, 30,000-square-foot facility with a standing-seam metal roof was built quickly and economically.

The ability to do so depended, in large part, on the ability to use a metal roof on the new building. Metal roofs also have low maintenance costs. Standing-seam roofs can contract and expand with changes in the weather, so they adapt to the climatic conditions. The seams take the changes, not the building. Standing-seam roofs are also watertight. Leakage is practically unheard of, meaning there’s nothing to fix. They’re highly resistant to wind and weather, so damage in extreme conditions is generally much less than with other roofing materials.

Faith Family Church in Shiloh, Ill., is a “colorful” example of roofing possibilities. Its 16-inch-wide, field-machine-seamed-in-place roof panels create a single-unit membrane. These panels are installed with thermally responsive galvanized clips that slide within the base, allowing for thermal movement in either direction.

Metal roofs also last a long time. In general, metal roofs carry a guarantee of anywhere from 20 to 35 years -- and are usually expected to last much longer. This is a significantly longer lifespan than other roofing types. With continuing improvements in materials and coatings for metal roofs, the expected lifetime will likely continue to grow.

Environmentally Friendly

Today’s metal roof is quite likely to be yesterday’s refrigerator or automobile in that it has a very high recycled content. Many products from metal roofing system manufacturers contain steel made from discarded steel goods that were candidates for the landfill.

The high recycled content can also yield LEED® points if a church is considering certification through the Leadership in Energy and Environmental Design program (www.usgbc.org). On top of the high recycled content of metal roofs, they’re completely recyclable.

Metal roofs can also reap benefits for a church’s energy budget. A pitched roof creates an attic space containing an insulating air pocket, which helps control the amount of energy needed to heat and cool the building. Fiberglass blanket insulation is the most common material used in new standing-seam metal roofs and retrofit projects. On some projects, unfaced fiberglass insulation is laid directly on the existing roof surface before the new standing-seam roof is installed. In other instances, the insulation blankets are installed directly under the panels and stretched over the supporting structural members.

"Cool” Technology

In addition to these efficiencies, cool metal roofing can help churches keep energy costs down. The concept of a cool roof is this: The greater the heat buildup on the roof of a building, the greater the heat infiltration into the building. By decreasing the heat buildup on the roof, cool roofing keeps the building cooler. There’s less need for air conditioning, so electricity bills are lower.

East Jackson Church of Christ (Jackson, Tenn.)

A cool roof results from two major factors:

Emissivity -- the ability of a material to emit heat, via infrared radiation, to the surrounding atmosphere. Roofs with higher emissivity values stay cooler because the heat is released from the roof to the surroundings. Painted or coated metal roofs have a very high emissivity (about .85).

The more predominant factor affecting the roof temperature is reflectivity, the measure of the solar reflectance of a surface. A typical asphalt shingle roof has a reflectivity value between .05 and .12. Cool, nonwhite metal roofs have values ranging from .25 to as high as .4. The solar reflectance for white painted metal is even greater -- about .65.

Previously, white was the only cool roof color; it was the only naturally reflective coating that could stand up over time. Researchers developed complex inorganic color pigments (CICPs) to allow colored roofs to reflect as if they were white through the use of these pigments. The colored coatings meet Energy Star requirements, with a reflectivity value of at least .25. Since the development of the new CICPs, the ability of manufacturers to offer cool roofs in a spectrum of colors has become widespread.

“In the past, cool roofs were always considered white,” says Bill Miller, Ph.D., a Research Engineer with the Oak Ridge National Laboratory in Tennessee. He researches cool roof technology through a collaborative initiative between Oak Ridge National Laboratory and California’s Lawrence Berkley National Laboratory. Miller notes that “complex, inorganic color pigments reflect about 70 percent of the near-infrared energy of the sun.” In areas of the country where cooling costs are significant, cool, nonwhite roofs are gaining a great deal of attention.

With metal affording versatility, economic value and aesthetics, metal roofing is an option worth investigating for church leaders.

Chuck Praeger is the assistant general manager of the Metal Building Manufacturers Association and chairman of the Cool Metal Roofing Coalition. He can be reached at 216.241.7333 or by e-mail at cpraeger@taol.com. To learn more about metal building systems and manufacturers, visit www.mbma.com .