– By Mark Ward Sr. –
Natural beauty comes forth in zinc, copper, others. –
Seamless gutters became popular 50 years ago when chemists finally developed flexible vinyl paints that could be applied to aluminum and then rolled and stamped right along with the underlying metal. Yet unpainted gutters — primarily those made of copper or zinc — continue to enjoy a significant share of the market for custom home construction, renovation and restoration projects and certain commercial applications.
Copper gutters have been installed in the United States since colonial days. Yet while zinc gutters are a relative newcomer, brought over from Europe some 20 years ago, the metal has recently come into own as a material of choice rather than simply as an alternative to copper.
That trend is confirmed by foreman Mike Witt of Heritage Sheet Metal in Glenview, Ill. The company installs architectural metalwork, roofs and gutters on upscale executive homes throughout Chicago and northeastern Illinois, and into Wisconsin and Michigan. While Heritage installs aluminum and steel gutters, about 80 percent of its gutter jobs specify either copper or zinc products. Of that 80 percent, he adds, 50 percent specify copper and fully 30 percent specify zinc.
“Everybody loves copper,” says Witt, whose family business has installed the metal for three generations. “We started offering zinc gutters about 10 years ago,” he continues, “and in recent years they’ve become popular in their own right. Zinc has a neutral gray or blue-gray color that fits a lot of looks and is especially popular on homes with contemporary designs.”
Witt estimates zinc gutters can last 80 to 100 years. But the greatest attraction, as compared to gutter, is the fact that zinc holds its color. Major suppliers can even furnish pre-weathered gutters. “Copper patinas over time to a green or brown color,” he points out, “which many people like. But others want the look of their home to stay the same as it was originally designed. That’s why, these days, we work with many architects who only specify zinc.”
Since the current price of zinc gutters is comparable to that for copper, reports Witt, homeowners and architects are free to choose whichever material they prefer. Heritage Sheet Metal sources most of its zinc products from RHEINZINK America, a German manufacturer that established a North American operation in 2002 with headquarters in Woburn, Mass. Witt also has installed products from VMZinc, a French concern whose Umicore Building Products USA division is based in Raleigh, N.C. His chief distributor for copper gutter products is Chris Industries of Northbrook, Ill.
For commercial buildings, project manager Jim Fleming of Milwaukee-based Langer Roofing and Sheet Metal has likewise noticed an increase in the number of zinc gutters being specified — although not to the degree seen in residential applications. Zinc gutters are a fairly new product for his company, which primarily performs commercial roofing projects throughout southeastern Wisconsin.
“We took on zinc about 18 months ago because more architects are specifying the metal, especially for projects that are designed with a European look or a rustic look,” relates Fleming.
“But the uptick in zinc might also be due to the fact that copper prices have risen or architects can’t get lead-coated copper.” Lead has been used in architectural copper for a century to prevent copper runoff from staining exterior walls, but many jurisdictions now restrict lead-coated metal as an environmental threat.
In the year-and-a-half Langer Roofing and Sheet Metal has offered zinc gutters, the company has installed the products on three jobs and bid on half a dozen. Applications have ranged from a coffee house to a drawbridge tower and from libraries to municipal buildings. The company looks to RHEINZINK America as its main supplier of zinc products, but also has used VMZinc products.
While Heritage Sheet Metal reports 30 percent of its custom home projects specify zinc gutters, Langer currently installs zinc on only about 1 percent of its commercial jobs. Galvanized steel is the workhorse for industrial buildings, while copper remains the standard for specialty projects such as churches and historic renovations.
In meeting the call for zinc, even experienced gutter crews — including those at Heritage and Langer — first require training in how to fabricate and install the metal. To understand why, a quick of review of metallurgical basics is helpful.
Aluminum is lightweight and easy to work with. Installers can speedily lift and hang even lengthy sections of gutter, and then quickly miter corners because the aluminum is easy to cut. Yet the metal is weaker than steel, copper or zinc, while hot and cold weather causes it to expand and contract. Mitered corners and other joints are riveted and caulked, rather than soldered, and caulk eventually becomes brittle and must be replaced. And aluminum will corrode from a galvanic reaction if it comes in contact with different metals.
Galvanized steel offers twice the tensile strength of aluminum, but only about half the amount of thermal expansion and contraction. But because the product is typically about twice the weight of aluminum gutters, installers cannot lift and handle steel as easily. Furthermore, joints must be soldered rather than caulked or riveted.
Copper gutter installation requires much skill, if only because the metal’s high price means that crews cannot make any mistakes or waste any material. Zinc has historically cost less than copper but is more difficult to solder, has a higher rate of thermal expansion and contraction, and can become brittle in cool temperatures.
“You can’t work with zinc when the temperature is below 55 degrees,” attests Witt. “When that happens, we have to set up a heating room and then heat the metal both before and during installations.” While it would be easiest just to suspend zinc installations during the colder seasons, he continues, “We don’t always have that option. People who build executive homes are demanding customers and don’t want to wait. These homes can also be complex and have tight construction schedules. Nobody wants the job delayed just because of the gutters.”
When temperatures sit above 55 degrees, however, Witt reports that the softness of zinc is comparable to that of copper. “Though copper is a bit softer than zinc,” he says, “under the right installation conditions they’re both comparable to work with.”
Similar experiences are reported by Fleming for his crews’ commercial projects. “Zinc can’t be installed in the winter,” he explains. “At low temperatures the metal fractures and cracks. By contrast, copper can be installed in any conditions. Other than that, while copper is easier to bend, zinc is a reasonably forgiving metal to work with.”
Both Witt and Fleming acknowledge zinc is subject to higher rates of thermal expansion and contraction than copper. The two hailed the efforts of manufacturers, including RHEINZINK and VMZinc, to develop expansions joints and brackets to deal with the challenge and minimize deformation of the gutter trough.
“One difference between copper and zinc gutter jobs, though,” reports Witt, “is in the area of decorative accessories.” Copper gutters on custom homes are often adorned with decorative hangers, medallions, leader boxes and more. “But we don’t see nearly as many accessories specified for zinc gutters,” he adds, “because the metal is often used on homes with a streamlined design.”
Fleming makes the same report for his work with commercial projects. “Zinc is popular for a more contemporary look,” he affirms, “and so there’s less call for decorative accessories than we get for projects with copper gutters.”
While copper gutters are a mature product with an established niche, Witt and Fleming believe the popularity of zinc gutters is set to grow. For one thing, zinc is a “green” building product that, like copper, requires little maintenance, lasts for decades and is fully recyclable.
“The only thing holding back zinc as a gutter material,” believes Fleming, “is the difficulty of installing it in the winter. Other than that, its market share can only grow.” Witt echoes that opinion and observes, “Many owners and architects still don’t know about zinc. But the more they see zinc installed on buildings, the more familiar they’ll become — and the more it will specified.” GO