GOOD ENOUGH IS NOT ENOUGH Gene Walton, head of quality control at American Metal Roofs in Livonia, Mich., says that an installer, whether single-line or full-service, must think quality all the way, down to the underlayment.
“[We use] a synthetic 3-ply system woven for strength — it lasts an extremely long time,” Walton says. “With metal, there will be condensation, so you need a premium underlayment.”
Alex Biyevetskiy, co-owner of L/A Roofing, a metal specialist in New England, says measuring precisely is essential to keep the roof’s lines as true as possible. Panels, flashing, and seams interlock; any one inconsistency can compromise the entire roof’s integrity. “With metal, you have to make sure you’re very precise with your geometry,” he says. Flashing details, dormers, valleys, and other such elements can be tricky with metal.
Flashing often has to be cut on-site to fit a particular detail, as do metal shingles that meet roof elements. Walton says that when his crews install valleys, the shingles abutting the valley are turned with a metal break, to lock into the valley pan. “Each individual shingle that hits that valley has to be hand-formed, hand-shaped to fit,” Walton says. “With asphalt, you’re used to using tar and simple flashings; [with metal] you’re talking about a roof on there that’s permanent. The flashings are handcrafted —they’re made to be there for a hundred years.”
All that detail work and on-site crafting takes time; metal roof installations can take up to three to four times as long as a typical asphalt shingle job. The greater the complexity of the roof, the longer the job. Houston remodeler Strong was surprised to find on a recent project that the installation of a Berridge standing-seam aluminum roof (the first metal roof he’d ever done) took three weeks to complete. Strong, who subcontracted the job, says he thought “they’d have it done in two days.”
Deal estimates five man-hours per square on a typical aluminum roof installation compared with a conservative two hours on a typical asphalt job. “With metal, you have to take the time to get your measurements right. When you’re budgeting your time, you don’t think at all the same way you do with asphalt.”
Plan on a lengthy installation, Deal says. “You can end up working really cheap on a job if you’re not careful.”
SORTING IT ALL OUT With so much involved, some remodelers won’t touch a metal installation with their own crews. In New Hampshire, where heavy snow loads have made metal popular for years, Tom Avallone’s Cobb Hill Construction has remodeled and built a number of commercial and residential metal-roofed projects. But he never does the install himself. “Sub it,” Avallone says. “Don’t do it yourself. If you don’t know how to do it, don’t get involved.”
For full-service companies that do want to learn and control the process, Deal recommends focusing on a limited range of products and choosing a manufacturer that has an established track record and can provide factory or on-site training. Each manufacturer’s installation process is proprietary and unique, so experience with one isn’t necessarily transferable to another. And brands with a long history of producing a certain product often discover best practices that aren’t necessarily intuitive.
“Don’t assume you know one product because you’ve worked with another. You have to respect every brand’s material and how it functions,” says Deal, who uses aluminum shingle and standing seam products by Classic Metal Roofing Systems.
Deal says he prefers aluminum because it’s lightweight and won’t rust under any conditions. And because steel requires galvanization, carrying it means an additional layer of variables to consider in selecting a product.
“You have to know how that steel is made, how it’s coated, how thick the galvanizing is, and whatever else is on it,” Deal says. “Steel is totally dependent on the coatings. So you must know a lot [about the product].”
Steel is also more sensitive to scratching than aluminum, which makes it susceptible to rust because protective coatings can be scratched off. However, Biyevetskiy says, “steel is the most widely used roofing material in the industry because it is more affordable and still provides really good quality and longevity given a proper installation.” — David Zuckerman writes frequently on construction topics from his home in Brooklyn, N.Y.