Copywriter, technical writer, translator (FR>EN, ES>EN, IT>EN), journalist

Test of Metal

originally published in Award Magazine

Roofs and walls on a steadily increasing number of buildings shun traditional materials in favor of metal.

This is not a new phenomenon. “You’ll find metal used on roofing going back thousands of years,” says Wes Brooker, marketing director for American Buildings Company, citing buildings in ancient Greeks and many old churches still standing today.

Competitive products still adorn the lion’s share of roofs and walls, particularly since architects and project owners better understand the likes of bricks and petroleum-based roofing products better than the properties of steel, aluminum, zinc and other metals.

But the advantages of metal are making themselves more widely known in the building industry. “As our customers’ businesses grow, we need to be able to provide products that can work with a theme or corporate image,” says Rob Newton, regional sales manager for the cladding division of BEHLEN Industries LP. “Colors from one site to another need to match from one building to another on the same site, or at different sites.”

Case in point: Petro-Canada is betting on the colors its service stations now sport to last as long as the buildings themselves. The iconic gas station pared five or six different brands down to the one they use today. “Bright, clean, white, plus red being the corporate brand; those were things they were looking for in their rebrand,” says Vlad Sobot, president of Sobotec Ltd., the company that supplied Petro-Canada with its new Alucobond siding panels.

“In the past, I think limited color choices were the biggest hindrance to using metal,” Sobot adds, “the paint applications and quality of paint you could apply to metal.”

“Now with kynar finishes, you can achieve an almost unlimited range of colors and brightness.”

Of the two basic primary coating systems available for metal – silicone polyester and kynar/hylar – kynar fades much less than silicone, making the color last longer.

Color accents can also rise above the walls. “With flat roofs, if you want color on a building, you put it on trim or around the walls,” Brooker explains. “With metal roofs and colours, you can get a steeper pitch and use colors that accent the building: a bronze roof or a red roof or a green roof, whatever you want to do.”

RHEINZINK America Inc chose to set its zinc material apart by adding a trace amount of copper. “The zinc corrodes quickly until it forms a patina and creates a series of differences in light between the copper content and the zinc content,” says Georg Koslowski, RHEINZINK’s director of technical services. “The light reflected from the copper gives the alloy a distinctive blue-grey color.”

Design possibilities other than colour also enter into the equation. “You can create very unique, complex shapes in the manufacturing process that you couldn’t in the past,” Sobot says.

“You can curve it, make all sorts of different angles, make sheets that go 100 feet without any seams,” adds Brian Hofler, executive vice-president of the Roofing Contractors Association of British Columbia. “It’s up to the architect’s imagination.”

As an example, architects “wrapped” the zinc exterior of one Toronto hospital into the lobby through a window. “The exterior welcomes you into the interior,” says Blair Davies, the sales and marketing manager for Engineered Assemblies Inc.

Toronto’s Museum subway station, so named because it leads to the front doors of the Royal Ontario Museum, welcomes transit riders with hieroglyphics carved into the word “Museum” on the walls of the station.

“We did these in aluminum plate,” says Dan Boyd, general manager and senior estimator for Ontario Panelization, which created the hieroglyphically enhanced Museum signs.

Material choices originally included porcelain, which would have cost more. A newer option, aluminum composite panels, would have cost less. “It would look just as nice,” Boyd claims, adding, “Composite has been emerging in the market over the last five years, and architects are starting to learn about it.”

Looks and design aside, purveyors of metal roofing and cladding emphasize the durability of their products.

“Steel roofs, last, on average, 40 years with little to no maintenance,” adds Meredith Perez, BEHLEN’s marketing supervisor for roofing, “unlike gravel or tar roofs. No extra material goes into a roof during its useful life.”

Koslowski makes similar claims for zinc, crediting its durability to the protective patina it forms over time when exposed to the elements.

BEHLEN recognizing zinc’s benefits, sells Galvalume products for roofing and siding. Galvalume is a zinc-aluminum compound used to coat steel and act as a “self-sacrificing layer” against corrosion. “If the steel is nicked,” Perez explains, “the zinc patinas to protect the steel.”

Perez mentions another advantage specific to steel: “When steel comes off a building, all of it goes into the recycling stream,” Perez adds.

Steve Fox seconds that claim. “Steel may be the only construction product that is recyclable without any downcycling,” says the general manager for the Canadian Sheet Steel Building Institute (CSSBI).

By downcycling, Fox refers to the process whereby a material’s properties downgrade after being recycled a certain number of times, to the point that the material can no longer be recycled. “You can recycle steel products an infinite number of times without losing any of their physical properties,” Fox says.

Durability and recyclability are but two qualities that make metal roofing and cladding desirable for projects aiming for LEED certification.

The fact that metal roofs must have a slope, no matter how gentle, makes them excellent for channeling water. “You can get LEED points if you bring water off roofs and into cisterns or holding ponds,” Brooker says, noting that flat roofs aren’t traditionally designed with drainage in mind.

Rain water, Davies adds, does not taint the environment once it flows off a metal roof.

Brooker adds “cool colour” technology to the LEED mix. Cool colours reflect more of the light that strikes it than metals that sport traditional coatings. “You can have a dark green,” Brooker explains, “reflecting only 17 percent of the light, but as a cool colour, it reflects up to 28 percent.”

Resistance to damage other than that inflicted by ordinary exposure to elements also elevates metal roofs above competitive products. Hofler notes that metal fits well whenever a project’s requirements include non-combustible materials.

Areas that regularly experience high winds, like “hurricane states” and southern Alberta with its chinooks, see metal roofs stand up well. “As long as it’s properly installed,” Brooker says, “the whole roof will come off before any metal comes off.”

For all its durability, metal is relatively lightweight. “You can use it on high-rise buildings without adding lots of load to the structure,” says Sobot.

Building professionals who specialize in institutional/commercial/industrial (ICI) projects likely know most of the benefits metal roofing and cladding products offer. Metal’s reach within ICI itself, though, is expanding. BEHLEN’s Newton notes that grocery stores and restaurants like Boston Pizza are putting metal on their buildings.

Experts agree that the choice to use metal on a building dovetails with long-term ownership of that building. “In the southeast US, about half of our roofing business is roof retrofits,” says Brooker. “A school building may be 30 or 40 years old and they replace the roof every seven to ten years. Because of the longevity of the buildings, schools have gone to metal roofs.”

In Canada, Fox notes that municipalities drive demand for metal, noting as an example the number of arenas being erected in Ontario.

For all their advantages, metal roofing and cladding suffer several issues, not the least of which is perception. Despite the aesthetic and innovative uses architects find for metals on buildings they design, many people still think of corrugated metal siding and its unattractive cousins when the possibility of metal on a building is raised.

In spite of a favourable total cost of ownership, the higher initial cost also deters some people. Metal roofs, for instance, can be twice as expensive to install as a traditional flat roof.

But that cost difference may be shrinking. “With speculation gone out of metal markets,” Koslowski says, “we find metal is nominally 60 percent of the cost from five years ago.”

To overcome the initial cost hurdle, some metal roofing and cladding manufacturers offer warranties that last 35 years or more.

Koslowski notes a third stumbling block, owing partly to increased awareness of metal roofing and cladding: “We don’t have enough people who know how to use it,” he says.

For some industry players, faulty installations have inflated warranty claims since products did not perform as advertised. American Buildings Company offers a contractor installation certification program (CICP) that Brooker insists builders must take. “If you don’t go through the course or you don’t pass it, you don’t get the warranty.”

“Thanks to the CICP, we’ve cut claims on roofing down to a tenth of what they were,” he adds.

Sobot has his own people install metal cladding onto walls that contractors erect using traditional construction methods.

Several years ago, the BC Roofing Contractors Association established a steering committee and quickly found that the industry lacked a training program to prepare installers. “Existing sheet metal programs focussed on the installation of ductwork,” Hofler says.

Two years later, in collaboration with the Industry Training Authority (ITA) of BC and Construction Industry Training Organization (CITO) of BC, the Association completed the curriculum for a three-year apprenticeship for installation of architectural sheet metal.

Housed in a huge enclosed structure (“It looks like a large barn,” Hofler says), experts deliver training on a range of roofing work, such as steep, low-slope and two ply systems. With the Level One pilot done this past spring, the Level Two pilot slated for this fall and the Level Three pilot scheduled for 2010, the apprenticeship program is on its way to systematically producing trained installers.

Current economic challenges and resulting stimulus spending may provide the spur the industry needs to get more of its products into the market. In the US, President Barack Obama’s stimulus program has kick-started projects that sat on shelves waiting for funding. “We had quoted some schools two or three years ago,” Brooker says. “They couldn’t get the money together.”

Perez notes the same effect here. “Stimulus money in Canada has certainly pushed ahead a lot of projects that were going to happen anyway but will now happen faster with this money available,” she says.

“Things are not as bad as the media would have us believe,” she adds.

Davies particularly wants to deal with the perception of metal roofing and cladding. “It’s about unlimited creativity,” he says, adding, “The words ‘metal roofing and cladding’ don’t sound very inspirational.”

“Architectural cladding made from a variety of different metals offers builders, architects and owners unlimited creativity,” he adds. “It’s a range of materials, not just a set of products. People can do all sorts of really cool stuff with it.”

For a PDF of this article, click Metal_Roofing_and_Cladding.