There is no material more capable of protecting a structure from wind, rain, hail, fire, or rot than a durable and energy-efficient metal roof. The initial cost to install may seem high, but a standing-seam metal roof is the least costly roof option over the life of the roof because it is virtually maintenance-free and can last 50 years or more.
A standing-seam metal roof consists of metal panels running vertically on the roof deck. Each panel has two seams that stand up vertically and are crimped together to seal the joint and keep the elements from penetrating. A standing seam also keeps water from collecting on the surface, causing leakage.
A metal roof is durable, like an iron sentry standing guard over the top of the house. William Hippard, president of the Metal Roofing Alliance, in Seattle, Washington, says the building trades have taken a shine to metal roofing because of its attributes. “Without a doubt, metal roofs are cheaper in the long run,” Hippard says. “Many metal roofs will easily outlast any warranties that the company provides.” Warranties up to 50 years are not uncommon, but it’s not unusual to find metal roofing that has been in use successfully for 100 years.
Copper, galvanized steel, and aluminum (Galvalume is the galvanized version of aluminum) are the three metals most commonly used to build standing-seam or other types of metal roofs. All offer virtually the same durability, aesthetics, and finishes.
Beauty and Durability
Metal roofs once got a bad rap for their bright shiny colors and metallic look, but finishes are now much more compatible with home exteriors. Metal roofs have lost their “barnyard” image and now sport a host of colors, matte finishes, and profiles. Virtually any color is available, the metal can be finished to remove that “high gloss” metallic look, and the end product can be formed to resemble any roof product from tile to asphalt shingles or cedar shakes. Distressed-look metal roofs have an irregular pattern so that heavy hail storms won’t affect the surface appearance of the roof.
Dave Uppgren, a principal in Uppgren and Associates, the architectural firm that covered Domino’s Pizza headquarters in the largest standing-seam copper roof in the U.S., likes copper roofs because they are beautiful, durable, and almost maintenance-free. “About 90 percent of the decision to use copper for the roof was based on aesthetics,” Uppgren says of the stunning installation. “There really are no maintenance problems. As with any metal roof, snow sliding off can become a big issue and we’ve probably spent more time preventing snow from falling onto the public areas than to repair leaks.”
Energy Efficiency and Value
From an appraisal standpoint, Hippard says metal roofs are so durable and desirable that they add approximately $1.45 per square foot to a home’s overall value. Insurance companies give discounts of up to 35 percent to homes with metal roofs because when properly installed they are virtually impervious to wind, hail, and fire.
Metal roofs are also energy efficient. A metal roof can reflect the sun’s energy and block heat transmission from the roof to building members and living space. “Paint manufacturers have also come up with good reflective properties for the coatings so you can reduce your cooling bills in the summer by 25 percent,” Hippard says. “With the recent measures passed by Congress, homeowners can now get a tax credit for putting metal roofs on their homes,” Hippard says. As of January 2006, homeowners installing a metal roof can claim 10 percent of the total cost—up to $500—in deductions for energy efficiency improvements. Properly ventilating the roof is vitally important to its efficiency and lifespan.
Installation of standing-seam metal roofs is best left to the pros. “The biggest problem with any metal roof is expansion and contraction over long distances,” Uppgren says. A good roof system is designed to accommodate that movement. Roof components may be manufactured on site or arrive as pre-formed metal panels. Connections are made from underneath with clips. The best metal roofs do not have any fasteners applied from above because every hole made in any roof can lead to leakage.
Metal roofs are prone to a condition called “oil canning”. Tension irregularities during crimping can result in wrinkles or waves on the flat face of the roof. Ask the roofers how they avoid it, if there is a system of checks designed to eliminate oil canning, or how they will respond if it occurs. Since it is a common condition addressed by manufacturers and roofing systems, a good installer should have a ready response.
Metal roofs are lighter than asphalt shingles so it’s possible to add a new metal roof over an existing asphalt surface. If there is only a single layer of asphalt shingles on an existing roof, a standing-seam metal roof can often be applied over it without the need for a tear-off.