Architects, installers and manufacturers often cite metal wall panels as an easy way to refresh the exteriors and upgrade the energy efficiency of outdated commercial buildings. Metal wall panels are a good choice for such exterior retrofits for several reasons: they’re lightweight, cost effective, long lasting, and require minimal maintenance. They also offer significant design flexibility due to a broader selection of panel profiles, sizes and colors.
Metal wall retrofits make old buildings new breathe life into tired communities
Preformed metal wall panels are manufactured from a variety of metals including aluminum, copper, steel and zinc. Copper and zinc panels are typically left unfinished, allowing them to develop a natural patina that is both protective and aesthetically pleasing. Aluminum and steel panels are typically painted or coated to protect them from the elements.
According to Rob Heselbarth at Petersen Aluminum Corp., Elk Grove Village, Ill., new developments in coating technology are allowing longer life spans for the finishes as well as the panels. The choice of colors ranges from standard hues to custom-matched tones. But it’s usually the profile that has the biggest impact on the textural appearance of a building, Heselbarth says. Three of the most popular profiles are corrugated panels; flush and reveal panels; and composite panels. All can be used to create distinctive reveals, shadow lines and other architectural effects.
“Metal wall panels can typically be added to an existing building without structural modifications that can be costly,” says Tami Moschioni, AIA, senior associate and senior project architect in the Houston office of Page.
Metal wall panels are an effective solution for building exteriors that are either worn or deteriorated, or in need of a new look, notes Heselbarth. In many cases, some of the existing façade material can be kept in place, minimizing work and waste.
Tops in Versatility
Moschioni says there are two options for long-span panels. When stiffeners are incorporated, certain flat metal panels can be dimensionally fabricated in large sizes. In addition, panels that are typically 8 to 12 inches wide can be fabricated as an interlocking system, with panels in longer spans of 20 to 30 feet. The two options can be used to achieve different aesthetic design goals, she says.
Metal panels are typically accurate to field-verified dimensions, with the flexibility for end panels to be cut and fitted on-site. “Panels can also be field-fabricated on smaller projects with tight schedules,” says Moschioni. “They’re easily lifted into place and installed with mechanical fasteners and can be applied as a sealed wall system or a rainscreen system, depending on the design goals for the project.”
Metal panels and metal furring are easy to source and install, and continuous insulation can be used within the furring channel, allowing the skin to be applied over an existing façade and still meet current energy codes, Moschioni says. “This can be achieved with a minimal increase of wall thickness so that the building doesn’t encroach on adjacent property lines,” she adds.
Two recent retrofits in Houston illustrate Page’s approach. For the Robinson Westchase Library, Page specified aluminum composite material (ACM) panels “because they gave us the most flexibility for use in various configurations around the building where we were replacing the exterior brick cladding,” says David Quenemoen, AIA, LEED AP, design principal. “The dark bronze color and large format of the panels also provided a nice contrast to the existing brick parts of the building.”
The New Process Steel headquarters was given a makeover using face-fastened, linear-formed panels reminiscent of the corrugated metal siding that originally covered the warehouse, but with a cleaner, more modern profile, Quenemoen says. Page also used a perforated panel with a matching profile to create the enclosed parking area.
Metal Walls as Art
Sameer Kumar, RA, LEED AP, director of enclosure design for SHoP Architects in New York City, notes that formed sheet metal panels are widely considered for exterior applications, retrofit or otherwise, because of their durability under weather exposure and the design options they offer, both in shaping as well as finishes.
“We at SHoP like to use a variety of different metals and combine them with natural or applied finishes to achieve the desired expression,” Kumar says.
Compared to other exterior materials, metal panels are relatively easy to work with, especially when being formed into 3-D shapes. “They can also be perforated easily, which is a great advantage for further enhancing their response to light and shadow,” says Kumar.
SHoP applies metal panels as a rainscreen system within a pressure- equalized wall construction in order to ensure the highest degree of weathertightness, he says. “Metal panels are very conducive to that.”
Two years ago, the architects completed the renovation of SITE Santa Fe, a contemporary art institution located in the Railyard district of Santa Fe, N.M. The work included a dramatic exterior makeover of the building, a former beer warehouse converted for the institution’s use.
“The folded, perforated aluminum system defining the exterior of the building was calibrated to respond dramatically to the intense Santa Fe light,” says Kumar. “In keeping with SITE’s scrappy nature as an institution, these elements were reserved for the two major entrances, with a simple gray stucco used on the long, mostly windowless walls in between.”
The exterior, he adds, was carefully designed so as to be appropriate both for SITE’s immediate context in an old railyard as well in contrast to the traditional construction methods and effects that prevail in the surrounding cityscape. “The exuberant new exterior is intended to signal a welcoming gesture to the community, while also serving as an iconic new presence for the institution as it moves forward,” Kumar says.
Bring on the Drama
Metal panels can give any outdated design a modern, sleek, clean look, says Gordon Jones, president of Ralph Jones Sheet Metal, a fabricator and installer based in Arlington, Tenn.
“Metal panels are easy to conform to any design,” says Jones. “Some can be curved; we can miter corners to achieve all kinds of different looks. Colors can be mixed and matched, and different materials can be used such as aluminum, copper, Corten, Galvalume Mill Finish, prefinished steel, stainless steel and zinc.”
The metal skin also provides a thermal barrier when properly installed as a rainscreen system, Jones says. Insulation can easily be supplemented to improve the energy rating of the building, in turn helping the owner conserve resources, and the property benefits from added beauty and modern design.
One example is the Grove Park Office Building in Memphis, Tenn. An exterior skin of aluminum composite material (ACM) cladding panels was applied over the 40-year-old building to bring it back to life. “We also used copper flat lock and standing seam panels to pull it all together,” says Jones. The shadow and seam lines of the standing seam panels create visual interest.
For a distinctive look, pre-patina copper panels were specified. Pre-patina copper is a relatively new product achieved through a manufacturing process that duplicates and accelerates the natural aging of copper. The material has a patina on one side that would normally take 25 years or more to form.
Ideal for Retrofit
Tuschall Engineering in Burr Ridge, Ill., fabricates and installs metal panels. One reason that principal Jim Tuschall considers metal a good choice for an exterior retrofit is that there are so many profiles to choose from. “You can do vertical or horizontal,” Tuschall says. “There are many different options for each panel type. In addition, there is a virtually unlimited choice of colors, and most of the paints have finishes that are warranted for 20 years.”
The company fabricates aluminum, copper, galvanized steel and zinc wall panels. Copper and zinc are in especially high demand, he says. Compared to other building materials, metal panels are lightweight, “easy to stack, easy to maneuver in confined spaces, and easy to crane into position. And the structure needed to support them is easy to install over existing block or another material. It’s very adaptable.”
Tuschall Engineering does numerous retrofits over existing block walls that are cracked and may be leaking. “We can put up a single-skin metal panel to give [the building] a waterproof wall as well as something aesthetically pleasing. We can also add as much insulation as [the client] wants, which is a very inexpensive process.”
Tuschall continues, “By changing the entry canopies, soffits and fascia and redoing the exterior, we can bring the building up to modern design standards and make it easier for the developer to rent or sell.”