Metal has a loyal following among architects, who like the crisp lines, versatile looks, and durability. Some metal products can last as long as 60 years or more, but they cost three times as much as conventional roofing.
Pros for Metal Roofing:
Lightweight. Metal is about the lightest material you can install on your roof. Though weight varies based on type, contractors and manufacturers say aluminum varies from about 50 pounds per square, while steel can be anywhere from 100 pounds to 250 pounds per square, says MetalRoofingSource.com.
Longevity. Metal offers good weather resistance and can last a long time. There are rumors of copper and zinc metal roofs in Europe lasting well over 100 years. Though this might be possible with care and maintenance, you can reasonably expect a metal roof to last about 60 years, give or take.
Long warranty. Many metal manufacturers offer limited warranties that last up to 50 years.
Stellar extreme-weather performance. Contractors say metal is excellent at preventing leaks, offers good wind resistance, and is fireproof. In fact, says the Metal Roofing Alliance, some insurance companies offer home buyers up to 30% reduction in premiums for weather-resistant metal roofs .
Environmentally friendly. One of the most energy-efficient roofing materials, metal reflects heat and helps keep houses cooler in the summer. Plus, the product often contains high, recycled content and is itself recyclable.
Cons for Metal Roofing:
Very expensive. Metal’s biggest drawback is the cost. Though manufacturers say prices have come down, metal, on average, costs three times as much as asphalt. Pricier metals such as stainless steel, copper, and zinc can cost way more.
Can have a harsh appearance. Metal has a long history on barns and agricultural buildings, but for those who aren’t familiar with this look, it can be harsh in a residential subdivision.
Extreme expansion and contraction. Critics contend that some metal roofs expand and contract quite a bit, which compromises their long-term performance and their ability to remain water tight. This is often a function of the installation.
Past failures and perception issues. Architects say there was a time when basic corrugated metal roofs corroded in 10 years or less. In some seaside applications, rust on some roofs is visible. Most products today, however, are made with alloys and specialized resin paints that can handle salt spray, extreme heat, and heavy precipitation without issue, the industry says.
Product selection is important for good performance. Though high-performing materials such as stainless steel, copper, and zinc are available, low-end steel products are still available. Architects advise against low-grade metals that are thinner and less durable, especially near seaside locations.
Nigel F. Maynard is a senior editor for Builder magazine.