Using Metal to Create Façades that Break the Mold

By Jordan Scott

From the imposing columns of Greek temples to the durability of ancient Egyptian pyramids to the intricately detailed Gothic cathedrals, people have pushed the limits of architecture for millennia. Fast forward to the early 1900s, when society was adapting to a quickly developing world following the industrial revolution. Architect Walter Gropius founded the Bauhaus architecture school, which operated from 1919 to 1933. Bauhaus
had a significant impact on 20th-century architecture, emphasizing simple, functional designs that could be mass-produced. While Bauhaus designs vary greatly, many associate the approach with clean lines and boxy shapes. The style still influences some of today’s buildings, and architects worldwide also push the boundaries of geometry and engineering. Expressive design is no longer limited to religious buildings; institutional, commercial, hotels, and even high-end multifamily construction take on shapely aesthetics.

Metallic Trends and Shapes

The use of metal to highlight specific building areas is a growing architectural trend. Mike Wallace, president of Americlad LLC, based in Rogers, Minn., says metal can be used in entrances or at specific elevations to enhance the aesthetics of that part of the building. Wallace sees the use of curved metal panels or custom corrugated profiling increasingly. Combining complex shapes with other façade elements such as unique metals or textured coatings reminiscent of stucco finishes is a trend that adds visual interest. Architects who design universities, private offices, and other buildings in larger metro areas tend to gravitate toward these trends.

Nathan Mittag, vice president of Architectural Wall Systems based in Des Moines, Iowa, says architects increasingly specify perforated metal panels, which often sit in front of glass or metal. Mittag says perforated metal facades are often specified with marine-grade aluminum and metals with natural finishes to create an industrial look. In some instances,
metal panels can be curved to wrap around a building.

Rainscreens are also becoming more popular. Wallace says 65-70% of his company’s panel systems are true rainscreen systems, which do not require caulking. This, he says, has helped increase specification throughout the U.S. These systems are also low maintenance, making them a durable choice for shedding water while adding an interesting visual element to a building.

When it comes to coatings, James Howell, associate product manager for Sto Corp. in Atlanta, says true metallic coatings allow architects to use a coating that pops. He says architects specify metal panels over textured materials to create an eye-catching aesthetic.

Wallace says aluminum with a painted finish is still the dominant metal and coating combination. However, he says projects are now incorporating stainless steel with painted aluminum to highlight a particular part of the building. In addition, copper and zinc panels are becoming popular, though on a smaller scale.

Design and Installation

According to Wallace, contractors interested in working on complex metal façade projects need to have an appetite for this type of work. They need to understand difficult façade work and custom curtainwall installation. Wallace says less experienced contractors who take on complex work often struggle because they can’t handle the demands of unique geometries properly. Experienced contractors and suppliers can help guide the project in the right direction.

Following the design-assist approach when working with complex metal geometries can ensure the design can be built and meet budget requirements. Involving the glazing contractor and supplier early allows the architect to work with them to make their design a reality.

“One thing we’ve always found is that architects want to put their signature on a building. Their drawings can’t always be built 100% to their design, but we’ll try to get as close to it as possible. Ninety-nine percent of the time, the architect is good with our modifications. Custom isn’t a dirty word,” says Wallace, emphasizing that early involvement is crucial to the project’s success. “Custom or curved profiles with welding, grinding, and other manufacturing processes can be challenging, and we need to understand the budget. When a project gets complex, the cost per square foot can go up substantially. We’ll design the panel to support whatever engineering is required, including hurricane [resistance].”

Curved metal panels come with their own considerations. Mittag echoes Wallace’s point about the importance of communication among the architect, contractor and fabricator before drafting the specification. He says metal fabrication processes vary for different curved metal products. For example, the metal panel may be rolled into its radius shape, while the extrusions behind it are stretch-formed. Each manufacturing process has different tolerances, as well. Mittag says it’s critical to align different manufacturing methods and tolerances to create the product in the shop drawing successfully.

Structure and appearance are the two primary considerations for perforated metal panels. Project teams need to understand the minimum thickness required to meet the structural needs. However, thin perforated metal diminishes flatness.

“Visual mockups are critical to analyzing the thickness needed structurally while still meeting design requirements,” says Mittag, who suggests slightly thicker metal panels, so the design remains flat.

Karine Galla, senior product manager at Sto Corp., adds that smooth coatings are less forgiving, while textured coatings better reflect sunlight, creating a shinier effect. Howell recommends specifying a textured look for a better aesthetic.

Using fully engineered metal systems can provide installation benefits, according to Galla. She says specifying a fully engineered system ensures compatibility as every component comes from one source.

A Metal Oasis

The King Abdulaziz Center for World Culture takes metal architecture to a new level. The unique, free-form facades of the property’s five buildings were designed to mimic bright pebbles in the sand. Architect Snøhetta and façade construction specialist seele, based in Gersthofen, Germany, achieved the desired effect with thousands of three-dimensional, bent, stainless steel tubes that wrap around the building without any edges.

Each of the approximately 70,000 tubes is bent into a unique geometric form corresponding to its position on the structure, covering nearly 326,000 square feet. Seele created special software programs so the bending and measuring machines could communicate and learn from each other. Before the programs’ development, seele undertook several tests to produce a properly bent tube. Implementing the solution reduced errors to less than 3%.

3-D data was vital to the project’s success, allowing the geometry to be
specified in advance through simulations. Each tube has its own QR code and laser engraving indicating individual instructions and the location of each tube on the façade.

Jordan Scott is a contributing writer for USGlass magazine.

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