Whether you’re building a new home or putting a new roof on an existing structure, you might want to consider a metal roof instead traditional materials. Once seen primarily in mountainous areas with heavy snow loads, standing seam metal roofs are becoming more common in our area and for good reason.
“Basically, you’re looking at a lifetime roof,” said David Bowden of Bowden Sheet Metal in Bar Harbor. “With asphalt shingles you’d probably do the roof three times in your lifetime instead of one.”
Metal roofs are nothing new. Some historians trace the origins back to 970 B.C., when a copper roof was fitted to a temple in Jerusalem. Closer to home, the Ellsworth City Hall is a prime example of a copper-roofed building. It was built in 1934. The copper was replaced in 1999, during renovations to the building.
With the advent of steel production in the late 1800s, metal became an alternative to the more expensive copper roofs. Sheets of corrugated steel became the material of choice for low-cost roofing and were used to cover everything from sheds to homes to barns.
As popular as these steel roofs were, there were problems.
Aesthetically, they were a disaster. Each roof had the same shiny galvanized silver coating, at least until the coating weathered and the rust began to show.
Another drawback was noise. Rain, hail and even wind noise was somehow amplified for those inside one of these “tin-roof” buildings.
Modern metal roofs don’t have these issues.
Rust is no longer a problem. Modern metal roofing uses steel that is coated with zinc or with a combination of zinc and aluminum. The coating bonds with the steel and acts as rust-proofing. The steel sheets then are painted using baked-on enamel.
Homeowners now can choose from a variety of colors. Bowden said one of the brands he recommends is available in 30 stock colors. The company offers custom colors for an additional cost.
Metal roofing even comes in different textures. Besides the standing-seam roofs, which are the most common, steel roofs are made to look like shingles, cedar shakes, tile and slate. Some architects are designing homes where metal roofing is used in conjunction with another material to achieve a certain effect, Bowden said.
He notes that a recently built shorefront home in Bar Harbor has a slate roof for the main section of the home and black metal for the remainder.
Noise is no longer a problem; thanks to the ceiling insulation used in homes today, metal roofs are practically noiseless.
With new homes, the metal roofing is fastened directly to the sheathing on the roof. Metal roofs can be installed on old homes as well as new, although Bowden said it’s easier to work on a new house.
A metal roof even can be put on over the old shingles as long as there is only one layer of shingles on the roof. With two or more layers the fasteners for the metal roof might not get enough hold in the roof sheathing. In that case, the shingles should be stripped from the roof, he said.
Bowden said he puts a layer of building paper between the metal roofing and asphalt shingles to keep the asphalt from abrading the metal as it expands and contracts during temperature changes.
Bowden uses double lock standing seam roofing, a traditional method where the seams between sheets of roofing are folded on top of each other and a seamer is used to lock them together. This method is much stronger than the single lock or snap-on systems, he said.
Of course there are disadvantages to metal roofs.
First, there’s the cost. An asphalt shingle roof is less expensive to install and can be one-third the cost of metal, Bowden.
Roofs with tricky angles or skylights require extra labor. “It’s a little more time-consuming,” Bowden said.
Metal roofing is not recommended for roofs that have less than a 3-12 slope, Bowden said.
Snow sliding off a metal roof also can be a problem, especially around entryways. Snow stops usually are installed in these areas to hold the snow on the roof in these areas, Bowden said.