Best Practices for Working with Architectural Metal
By Rebecca J. Barnabi
Planning is essential to keeping architectural metal projects on time and budget, particularly given the supply chain challenges the industry is currently facing. “Measure twice, cut once,” says Nick Iaquinto, metal department manager for Midwest Glass Fabricators in Highland, Mich. Otherwise, material and time are wasted. “No one can afford to mess anything up these days,” he says. “It’s hard to hide mistakes [with glass and metal].” Companies are not ordering extra supplies right now, because of supply shortages and higher costs, he says. “Nowadays, it’s all about availability.”
Iaquinto advises architects and project managers to check the structural applications of their projects and consider options when it comes to the finish. For example, “Black powder coating is difficult to get right now,” he says. Especially, he advises research. “Make sure your system has been engineered for the type of metal you want to use,” Iaquinto says.
The Metal Look
“In our world, almost all of our material that we manufacture for glazing is aluminum,” says Greg Beane, inside sales representative for PAC-CLAD, based in the company’s Andover, Minn., location.
According to Beane, working with steel and aluminum together is like mixing oil and water. So PAC-CLAD attaches aluminum to aluminum in glazing applications. “They stay together in the sandbox,” Beane says. For example, aluminum is attached to painted aluminum for trim around windows. “The façade part — that’s our industry,” he says.
PAC-CLAD also works with aluminum composite material (ACM) and insulated panels, but the type of metal in glazing applications, says Beane, who has been in the industry since 1985, depends on the architect’s design. “Really, it’s architecturally driven.”
One new option in aluminum finishing has a woodgrain appearance. “Those are some of the looks that are starting to pop up that I wouldn’t have seen 10 years ago,” Beane says.
Mike Wallace, president of Americlad in Rogers, Minn., has been in the industry for 35 years. He says that some metals may abut to other metal products, such as copper, zinc or steel composite, but a barrier is placed between the two products. “So, they’re essentially separated from the curtainwall system.”
Tracy Hultin, president and CEO of Ellison Bronze Co., in Falconer, N.Y., says different metals are used for different reasons in glazing applications. “Selections can be made because of aesthetics, performance, the need for customization, or influenced by cost,” Hultin says. Bronze offers a natural or historical look, while aluminum is economical, recycled, and available in unlimited painted and anodized finishes. Likewise, stainless steel is easy to maintain, corrosive-resistant and highly customizable.
Gauge of Metal
Material specification may also vary depending on where in the application the metal is installed. Gauge, for example, refers to the thickness of the metal and certain applications may call for a thicker gauge than others. Beane recommends a thinner gauge in glazing around windows, such as .04. A thicker glaze, such as an eighth of inch of composite aluminum, may be better on a larger surface because it stays flatter. Composite aluminum also works for spaces between and around areas on the exterior of a structure.
Wallace says that the thickness, or gauge, of the metal is dictated by the overall dimension of the storefront or curtainwall. Also, large curtainwall applications, such as those going from the floor to the ceiling, “typically are done in a heavier gauge. So it really varies [depending on design],” he says.
Hultin says most manufacturers use their own standard gauge, which is based on use and function. “While thicker material is stronger, it also means that there is a limit on the degree of manipulation that can be performed, which will result in more rounded corners where the bends occur,” she says.
Gauge is also important when working with steel. As with other materials, the application will likely determine the needed thickness. According to Iaquinto, steel is difficult to cut in the field, so is usually pre-cut in the shop. Aluminum can be cut in the field, and, for aesthetics, steel is often placed over aluminum.
Architects usually want a flat surface in design and a thicker gauge eliminates deflections, says Eric Steele, director of business development and marketing for Zahner in Kansas City. “You’re trying to avoid what you call permanent set,” he says, explaining this is when the metal bends slightly from environmental circumstances but doesn’t return to its original shape.
Specification of Metal
A number of considerations also come into play when specifying metal. Beane says these can include geographic location, design and R-value. Hurricane-prone areas, such as Florida, often use ACM which can handle certain windloads. R-value is important for keeping the cold out of a structure. Again, that depends on geographic location, because a structure in Arizona is not as susceptible to cold as a structure in Minnesota. In those northern climate zones, condensation can also be a concern if the cold air enters a structure.
Wallace recommends glaziers reach out to the manufacturer when they have questions about material selections and installation. Also, if a glazing contractor contacts manufacturers directly, the company will be able to abide by its warranty specifications.
Hultin agrees, adding, “Consult with a manufacturer sooner rather than later to discuss limitations and availability.” For example, she says if an entrance will be installed into a glass wall, portal framing may be required to support the doors. “This should be determined early because embeds into the concrete are generally required,” she adds.
The opening, Hultin says, “should be plumb, level and square … lead times are significant when a piece doesn’t fit.”
Hultin also advises installing entrance materials last. “If they are installed early, they can be damaged by trades entering and exiting with equipment.”
Rebecca Barnabi is a special projects editor for USGlass magazine.
Contact her at firstname.lastname@example.org.
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