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Working with Oversized Metal Panels

Transportation, handling and installation tips for oversized panels

Best Buy Metals May18 6

With the growing trend of glass manufacturers fabricating longer and wider sheets of glass, architects are designing more of their projects with larger metal panel sizes. These oversized metal panels have special transportation, handling and installation requirements.

Mishandling oversized metal panels can negatively affect both their performance and aesthetics. “Long-length panels have the tendency to buckle or fold if not sufficiently supported,” says Jeff Haddock, technical representative, AEP Span, Fontana, Calif. “This can put creases in the panel legs or the panel giving an unsightly appearance. Damage to the panel leg can also affect panel performance—weathertightness and wind uplift—by not allowing the panel’s male/female leg to fully engage.”

Oversized panels are not only longer, but they also weigh more. These two components make individual panels and bundles that are much more susceptible to damage. “Buckling and kinking are the best way to describe the most commonly seen damage,” says Brian Shelton, marketing manager, Chief Buildings, Grand Island, Neb. “It is also common to see localized bends and evidence of crushing at lift points and blocking/dunnage points when stacked. If sliding and articulating clips are not used or installed correctly, the added expansion and contraction of the long panels may create stress risers and lead to panel failure.”

Oversized Panel Transportation

Generally, flatbed trailers are 48 feet long. Material on these trailers is allowed to overhang the trailer’s end by 5 feet. This allows for maximum panel lengths of 53 feet to be shipped on standard flatbed trailers.

Photo courtesy of AEP Span

Photo courtesy of AEP Span

Longer panels may require stretch load trailers. “Stretch load trailers can handle loads of up to 100 feet long,” Haddock says. “Special consideration must be taken into account regarding the shipment of stretch trailer loads. Job sites in remote or mountainous areas can be very challenging to access with long trailers due to tight turns. Job sites also have a finite amount of area to handle larger-than-normal loads.

Steve Arnold, vice president of operations at Queen City Roofing and Sheet Metal, Springfield, Mo., stresses when transporting panels to make sure they are properly strapped down with foam or other soft materials in between the panels. “Delivering the longer panels takes special trucks and permits to ship longer panels,” he says. “If at all possible, we find it’s better to order coils and roll our own panels on-site.”

Oversized Panel Handling

To prevent damage, extra caution and care should be exercised due to the added bulk and weight of oversized panels. Comprehensive training of employees with panel manufacturer information also helps. Haddock contends an installer’s ability to handle oversized panels should be carefully considered before a project is bid. Safety procedures must be in place to accommodate any oversized panel.

Photo courtesy of Chief Construction

Photo courtesy of Chief Construction

Nathan Libbey, division III manager at Best Buy Metals, Cleveland, Tenn., says oversized panels usually require special crating or multiple forklifts to offload or load. Mike Wallace, president of Quality Metal Crafts LLC, Rogers, Minn., says the crates need to be reinforced to withstand the additional weight and also be built in such a fashion that makes loading and unloading a simple process for when the material arrives on-site. Larger tarps may be required to ensure oversized panels are kept dry on the job site.

Rodney Hiller, sheet metal superintendent at Queen City Roofing and Sheet Metal, agrees that in addition to bigger equipment like lifts, cranes, vacuum lifts and panel rollers, a key to handling oversized panels is limiting the times you must move them. Also, “Make sure you have plenty of manpower when handling oversize panels,” he adds.

Trent Tyler, steel supervisor at Chief Construction, Grand Island, says a spreader bar and rigging should be used when handling or moving panels at the job site. “This will help eliminate difficult maneuvers through  difficult corridors,” he says. “Bundle placement while stored or in preparation for installation is important to minimize handling. Installation begins once the bundles are broken and it is more difficult to move single panels without damage and caution is advised. One example: an architectural vertical rib standing seam panel will need to be stood on its side, secured face to face with another panel while lifted with a wide spreader bar and rigging. When picking bundles with lifting straps, it is advisable to use flat plates in conjunction with your rigging to prevent crushing the corners of your material.”

Hiller recommends having a good game plan before you start your job and definitely having a morning huddle with the crew who will be handling and installing the panels before starting on that day. “It is important to let the crew know the importance of these oversized panels not being damaged during the project,” he says. “Explain to them the costs of the panels and how hard it is to get replacement panels. You can’t just expect the crew to know these things. Communication is always the best way to avoid problems in the field.”

Today's wall panels have interesting internal geometries, which can create interesting textural patterns. Photo courtesy of Metalforming Inc.

Photo courtesy of Queen City Roofing and Sheet Metal

Accurate Oversized Installation

According to Tyler, oversized, through-fastened metal wall panels are installed in one of two ways. One way is to pull the panel up with a rope and a device to secure them together. “Drilling a hole in the top of the panel that will later be covered by trim offers a method of attachment,” he says. “When doing it this way you will need to consider additional support for the middle of the panel to prevent bow outward or possibly buckling the sheet. Alternatively, taking the top of the panel up in a man lift while personnel hold the bottom from the ground is a proven method to get to the full upright position. It may be necessary to support the panel 6 to 10 inches from the top of the panel to reduce the distance between support, and prevent bow out and buckling on the way up. Once you establish how to lift, you will need to decide if there will be any bow out in the panel as you are setting the initial fastening points (wind, insulation). This can be minimized with personnel on a second lift at mid-height. Moving your initial fastening point from the top down one girt level will decrease the distance to the initial bottom fastening point.”

Maintaining proper laps and edge alignment is requisite when oversized metal sheets are installed, as any misalignment at one end translates into a major misalignment at the other end. “Additional man lifts may also be warranted in wall applications, primarily to maintain control of the panel at mid-height during installation, but also to limit bow out,” says Shelton. “If bow out is not controlled and screw installation sequence is haphazard, then the installation itself may introduce oil canning and other visually unappealing conditions.”

Manufacturing oversize panels is made easy by the large processing area and multihead configurations of the PANELBuilder CNC routing machines. These typically have 72-inch or 84-inch process width, but they can go up to 128 inches or more. Photo courtesy of AXYZ International

Wallace says stiffening and leveling play an important part in oversized panel installation success. “Larger panels will most likely require stiffeners of some type,” he says. “Know that stiffening isn’t necessarily there for flatness. It can help somewhat, but really more to meet the performance requirements based on the design loads. [Also,] start with a properly leveled flat part. Traditionally, if a fabricator is working with a product that is subpar in flatness, it could lead to a panel that is not flat and could result in oil canning. Additionally, expansion and contraction must be taken very seriously when building larger panels and ensure that the design works for the application.”

Burlington, Ontario, Canada-based AXYZ International’s PANELBuilder CAD/CAM software has templates to assist in creating mounting holes for oversized panel stiffeners. Peachtree City, Ga.-based MetalForming Inc.’s folding machines have innovations that allow longer sized panels with varied geometric shapes to be produced.

Art Hance, president of Washington, N.J.- based Hance Construction Inc., makes sure his erectors comply with manufacturers’ and industry-recommended panel installation techniques. “It is critical with longer panels that they are plumb as just a slight misalignment will be read as a sawtooth at the bottom of the panel,” he says. “This is especially noticeable when there is masonry walls with panels above. We are also seeing issues with newer high R-value panel systems with longer fasteners. The longer panels shrink and grow with temperature differentials and lead to fasteners failing. This can be exacerbated by improper use of impact guns for wall fasteners.”

Photo courtesy of Riess Construction