It’s unpainted: Installing bare metal roofs

– By Jim Austin, senior editor –

Options vary from some of the oldest products to new and innovative materials

Bare metal roofs … they have nothing to hide. Boasting unmatched longevity and durability as well as an attractive, clean look. Copper, zinc, stainless steel, Galvalume or any other unpainted metal roofing material all have their appeal.


Barrett Roofing photo

Those who have chosen to fashion and install unpainted metal roofing as their craft, respect the material of choice because, installed correctly, it provides a unique look and low-maintenance, long-lasting peace of mind. Because some of these metals are installed on high-end homes and historical restorations, they can lead to highly profitable jobs — another attractive point.

Some of the unpainted metal roofing materials require training unique to the material. The manufacturers of these materials will certainly offer training to help you and your crews install their products correctly.


Barrett Roofing of Danbury Conn., does it all when it comes to roofing, installing metal, including zinc and copper, as well as slate, tile and flat roofing. Ed Gezirjian says zinc and copper can go on anything. “There are a lot of high-end residences that want copper roofing,” he says. “Small entry ways or even as siding. We did a residential job, a house overlooking the Hudson River, we cladded it with Revere Copper’s pre-patinated product (Evergreen).”

Evergreen is copper, coated with a greenish coating to give the appearance of an aged copper product at installation. When the coating wears away, the copper will have begun the patina process and started to show its age.

For those of you intimidated by installing copper or zinc roofing, Gezirjian says you just need to follow the instructions. “With copper you can do almost anything and it won’t fail,” he explains. “If you follow the details in the SMACNA sheet metal guide, you’ll be fine. It’s time tested.

“The different between working with copper and working with zinc is night and day, from the design and installing the metal itself. Zinc can disintegrate in the right conditions.”

Gezirjian says, installed correctly, zinc roofing can last 80 to 100 years and it has “a lot of appeal with architects.” It offers an aesthetically pleasing look throughout its lifespan and works where lead-coated copper roofing used to be the accepted norm. Lead-coated copper fell out of favor with architects and installers because of the lead leeching into the ground.

Zinc suppliers RHEINZINK America and Umicore Building Products (VMZinc) offer thorough and extensive training classes. The No. 1 thing to know about zinc: The manufacturers of zinc roofing all recommend either venting the roof, using zinc panels with a protective coating on the underside or using a drainage layer directly under the roofing to allow moisture to escape. Moisture on the underside of the panels can cause erosion and eventual failure. Also, there are products available to create that venting space between the deck and the underside of the roofing panel.


Joe Wells is a copper craftsman and he is old school. Ironically, it was his eventual frustration with school that led him to being a roofer.



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“My father, seven uncles, two cousins and a brother were all in the roofing business in Georgia,” Wells says. “I wasn’t going to be a roofer, so I went to Tulsa to go to school. Turns out I didn’t like school. I had three months left and I quit.”

And he’s never looked back. Wells Roofing in Charleston, S.C., is the premier copper installer along the east coast. Before the economy dipped a few years ago, Wells Roofing was purchasing 70-90 tons a copper every year. It was used for roofing, decorative facades, gutters, countertops. Wells has copper on his house, his barn, his garage and his pump house.

“You have to understand thermal shock,” Wells says. “Zinc will move almost twice as much as copper and you really have to accommodate for that thermal shock. When I stand outside on a hot summer day and a cool shower comes through, I can hear the (copper) roof pop from the thermal shock, the expansion and contraction.”

Wells believes there is only one correct way to install copper. “We do it the way they were doing it 150 years ago,” he says. “It’s pre-pinned, hand-seamed and soldered. The longevity offered by copper … we’re not depending on caulking.”

And Wells’ installs have stood up to the toughest east coast hurricanes. He did receive a call after Hurricane Hugo in 1989 from a customer out on the island who couldn’t find his porch roof after the storm went through. After a little investigating, he found it two blocks away — still attached to the porch that blew off the house!

In addition to copper, Wells Roofing installs slate and tile roofing. Most of the work is on high-end homes or historical restoration. Wells has worked on buildings more than 200 years old, some which are almost 300 years old. He respects the history as well as the copper he works with.

“I’m attracted to the longevity copper offers and I like to say it starts out shiny like a penny and turns green like a dollar,” Wells says, admitting that these jobs can be profitable. Wells Roofing paid its dues.

“You learn by your mistakes and we made a lot of mistakes through the years and learned a lot,” he says. “I’m not boasting in any way, but no one provides the quality of workmanship we do. We do copper like some crews do (asphalt) shingles. It’s second nature.”

Wells, who has fought to keep his operation small, employees 16-18 men, some who have been with him for as long as 33 years; many more than 20 years. Long-time employees and long-lasting products.

Galvalume (Mill Finish)

Bare Galvalume or mill finish roofing has its place. Sometimes, you just can’t see it.

Galvalume, developed at Bethlehem Steel in the 1960s, is a surface coating applied to steel coil that contains 55 percent aluminum, about 1.5 percent silicon and about 43.5 percent zinc. Its major benefit is its self-healing ability. It combines the anodic sacrificial protection offered by zinc with the barrier protection of aluminum.

“It’s mostly installed in low-slope applications, big box buildings, distribution warehouses and factories,” says Rodger Russ, North American sales manager, roofing at Butler Manufacturing. “It’s being installed on buildings 5,000 to 10,000 square feet and on distribution warehouses in excess of a million square feet.”

Butler Manufacturing photo

Butler Manufacturing photo

You’d think you notice all that roofing, but because it’s installed on these low-slope buildings — Russ says as low as 1/4:12 — it’s pretty much impossible to see from the ground. And that’s part of the attraction for these projects.

“If no one is going to see it, it doesn’t have to be painted, so it’s more economical,” Russ says. “Designers will want a painted roof for anything with a slope of 2:12 or greater.”

Russ says Butler Manufacturing started installing unpainted Galvalume more than 40 years ago and that roofing is still doing it’s job. Almost all of that Galvalume roofing is Butler’s MR-24 standing seam roof system or the Butlerib II through-fastened roof system. Both systems are most commonly installed as 24-gauge roofing, but occasionally are installed as 26-gauge products as well as 22-gauge panels in high-wind areas.

Not everyone is trying to hide bare Galvalume. More and more it’s being installed in architectural and residential applications. It provides a brighter look and acquires a gray patina in about a year, depending on the climate.

You can see the bare Galvalume roofing in South Florida where Istueta Roofing installs a lot of 24-gauge single lock standing seam mill finish roofing on homes, many as a replacement for tile roofing. It’s lighter than the heavy tile product and provides a contemporary look with the Florida architecture, while providing financial benefits for homeowners.

The home pictured belongs to a Major League Baseball player.

Istueta Roofing photo

Istueta Roofing photos


“With the reflectivity, it helps keep homes cooler and can reduce air conditioning costs by as much as 20 percent, and possibly even more during the summer,” says Ariel Istueta, marketing director. “And it’s strong. It has the highest wind resistance you can get in Miami-Dade.”

Istueta purchases its Galvalume product from Metal Master Shop, a DM-ARM member of Drexel Metals’ regional manufacturers.

Frank Istueta, the owner at Istueta Roofing, likes working with the uncoated Galvalume roofing. “It installs easier and faster than coated metal roofing because you don’t have to be so careful with the panels,” he says. “There’s no coating to scratch or clean up. No coating means it’s very low maintenance, too.”

Stainless Steel

When you’ve been installing all types of metal roofing for well over 40 years, taking on a new product isn’t so intimidating.

Frank Brown of Frank Brown Roofing in Dallas, installs metal roofing like most people tie their shoes — it’s second nature. So it was no problem when he landed the job of installing the stainless steel roof on Austin Hall at Sam Houston State University. A crew of six to eight worked for more than six weeks to install the InvariMatte stainless steel from Contrarian Metal resources. The panels were fabricated and installed using traditional methods — including soldering — that were true to the period of the building.

“I’ve done roofing my whole life and while it was a lot of work, it turned out well and it’s a good product that should last indefinitely,” Brown says. “It will last the life of any building.”



Frank Brown Roofing photos


The Dallas City Performance Hall is a 70,000 square foot, 750-seat theater in the City of Dallas Art District. The $40.5 million facility opened a year ago and is designed for theater, music and dance performances. The building is topped with a dramatic roof made of varying ribbon-like forms that mimic the flow of music and sound. The innovative roof design is engineered to meet stringent acoustic and thermal programmatic requirements. The 25,000-square-foot double curve roof utilizes Kalzip Alupluszinc 65/400 continuous panels in varying lengths to form the natural layered wave. Kalzip Alupluszinc has an aluminum base with a natural zinc finish.

“The advantage of working with the Kalzip product on this project was that we were able to lay it down without having to curve it,” says Juan Rodriguez of Castro Roofing of Texas. “It was right at the limit where we weren’t sure if we would have to curve it or not. Kalzip sent us three panels to test and they didn’t kink or oil can like you’d expect steel or Galvalume to do.”


Castro Roofing photo

Because some panels were up to 305 feet long, the Kalzip panels were manufactured onsite. Rodriguez says the lightweight panels required 22 men on the ground with C clamps and another 22 men on the roof to move the panels into place. A special seamer created a rounded seam as opposed to the traditional 180-degree seam. Kalzip’s sound dampening material was added to the roofing assembly for additional acoustic mass.

Kalzip put the Castro Roofing crew through a training course at its own shop in Dallas. “The principles of working with this product are the same as other metals, but some of the details are a little different,” Rodriguez says. “This project required some special clips because we installed some special acoustical material under the roofing panels.”

Castro Roofing photo

Castro Roofing photo

For this project, a multi-layered sandwich assembly consisting of structural metal decking, high density acoustic batt insulation, rigid board roofing insulation, Kalzip sound dampening mat, plywood, weather barrier, anti-drumming membrane and zinc coated aluminum panels was used as the acoustic and thermal barrier. All of the roofing assembly was applied onsite.

“The trainer knew his stuff and was very helpful. If you do your due diligence on the front end, it will work out,” Rodriguez says.

Cold Rolled Steel

While the rest of the metal roofing world is fighting the look of rust, Wilson Roofing Division of Steamboat Springs, Colo., is installing as much cold rolled steel as it can!

Seth Wilson says high-end custom homes are the market for this product which, when treated, leaves a rusty look.

“Most cold rolled steel is 24-gauge metal,” Wilson says. It’s pretty tough to work with and if you’re not used to the heavy gauge, it’s hard.”

Wilson Roofing Division photo

Wilson Roofing Division photo

Wilson runs cold rolled coil through his Zimmerman Metals roll former, but he warns you have to keep the machine clean if you use it for other products, like painted Galvalume or aluminum.

“Problems come because cold rolled steel has to be treated with oil and oil gets on the tooling in the machines,” Wilson explains. “This requires breaking down the machine after a few jobs and cleaning out everything completely. Before you can run any new metal in the machine you have to clean it completely otherwise your new metal is messed up with oil and possibly some rust particulates on your new metal. That doesn’t bode well with that 35-year paint warranty your supposed to offer with your new metal roof.”

Wilson Roofing Division photo

Wilson Roofing Division photo

Like all metal roofing, cold rolled steel should be installed on a high-temperature underlayment, because temperatures under “rusty roofs get about as hot under a copper roof,” according to Wilson.

What installers have to be careful of is using the proper fasteners. “We use stainless steel clips and screws with all our rusty metal roofs,” Wilson says. “I haven’t seen it happen yet but I’ve heard galvanized clips will rust straight through and you can imagine what happens next.”

Wilson has been installing 24-gauge rusty roofing for going on 10 years. He says he hasn’t had to replace anything yet due to the deterioration of a panel, a problem you would be more likely to run into if you installed cold rolled steel at 26 gauge. MR

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