Rural building purchasers expect their metal buildings to stand up to extreme temperatures, winds, rain, and snow — and that’s OK because that’s how you build them. As a wall or roof panel, metal will last a lifetime.
The thing to remember is they are manufactured to be durable as an installed product. It’s equally important to remember that metal panels are vulnerable during the handling, storage, and application procedures leading up to and including the completed installation.
Most manufacturers include with their shipments at least some common sense type of instructions for handling and storage. “We put handling and storage instructions with our deliveries because customers need to know,” says Joel Viechnicki of American Building Components. Still, common sense can be an elusive trait.
“The easiest way to damage a panel is by not being careful, by not taking your time,” says Tracey Boyle of Union Corrugating. “And before you start, read the directions.”
Many rural builders have been working with the same products for years and experience is a most valuable tool. But reading directions for new information or a refresher can save you valuable time in the long run.
Once panels arrive at the jobsite, it’s recommended by most companies that you check the delivery for damage, and to make sure everything is there.
“All deliveries should be inspected immediately,” says Darrell Northen of Whirlwind Building Components. “If there’s any moisture, we can dry that off or shake it out of the panels.”
One of the most overlooked considerations is the storage of panels at a jobsite. If panels are not going to be installed immediately, they need to be properly stored. For any number of reasons, a contractor may not be ready to install panels as soon as they are delivered, so the longer they sit around, the more vulnerable they become.
“The best way to store panels is inside a building, but that’s not always practical,” says Bill Croucher of Fabral. “If they’re outside, they should be blocked so they’re not lying on the ground, and on an incline. They should be covered with a tarp and it should cover loosely, to allow air to circulate. That’s the No. 1 mistake of installers and do-it-yourselfers. Panels will last 30 or 40 years once they’re installed, but just a couple weeks at a jobsite, sitting on pallets, can damage the paint or even the substrate by trapping moisture between the sheets.”
In bright red letters on its storage and installation instructions, Fabral devotes the center of the front page to proper storage. The No. 1 enemy is moisture. As Fabral reminds its customers in literature it attaches to every delivery, when moisture remains in contact with galvanized, Galvalume, or aluminum panels in the absence of freely circulating air, white, black, or dark gray corrosion products begin to form. In addition to being an eyesore, this can shorten the life of the panel.
American Building Components includes information on application, storage, and handling with its deliveries. According to ABC, sheets should be unbundled, stood on end against an interior wall to allow for air circulation. If unable to store sheets in an upright position, strapping bands should be broken and sheets should be blocked off the floor with one end slightly elevated. Stacked sheets should then be completely protected from the elements while maintaining good airflow to prevent condensation. A properly draped canvas tarpaulin that allows airflow is an example of a good protective cover. Fabral, ABC, and others place a strong emphasis against using plastic as a cover, as plastic causes sweating and condensation.
“Improper field storage is one of the worst things we see,” says Northen. “Setting them out on the ground and leaving them there for a few weeks, it rains or condensates … it can do a lot of damage.”
If panels are damaged by moisture — or mishandling — on your jobsite, you will most likely be responsible if questions arise.
Metal wall and roof panels endure plenty of potential abuse before they’re fastened. At a jobsite, there are plenty of opportunities to damage panels — just think about how many times any given panel is touched or moved at a jobsite, either in a bundle or as a single panel. At a jobsite, Viechnicki says any number of mishandling procedures can damage panels. “When two guys are taking panels off the stack and handing them up to two guys on the roof, usually the first thing that happens is that one guy picks up a corner and drags the other end of the panel across the next panel,” he says. “That is scratching the paint all the way off.”
Today’s paints are a protective part of the wall or roof panel, designed to make the entire system more durable, as well as more attractive. Handling and installation procedures do not fall under the normal wear and tear paints are designed for. Wheeling Corrugating warns its customers that dragging of individual sheets from the bundle can scratch the surface and reduce the paint performance. The paint finish is tough enough to withstand normal weather conditions, but can be scratched and abraded if care is not taken. Some paint coatings are softer and may require extra protection during storage and handling.
Certain companies apply a clear protective strippable film on the outside or topside of the panel to help guard against scratching or what is referred to as transit abrasion. The Galvalume Sheet Producers of America (NamZAC) provides a wealth of information on handling panels with a Galvalume substrate. According to the association’s Web site (www.steelroofing.com), transit abrasion usually appears as scuff marks or particles of the backer coat which have been transferred to the topside paint coating or prepainted Galvalume building panels. This damage can result from improper paint curing, improper handling or shipping practices, and metal surface irregularities.
Such sheets must be removed immediately after installation. Sunlight can increase the adhesion of the film to the painted panel, which can also occur during storage — another reason to keep panels covered during storage.
“Probably the most common problem is scratching the paint, either with foot traffic or from dragging one panel over the one under it,” says Croucher. “Walking on ribs can cause local dents.”
Another potential problem when handling panels, either in the shop or at a jobsite, is bending. Distortion can take place when too few people transport a panel, or when it is held in inappropriate spots.
“Panels in a bundle can be lifted with a crane, with the spreader bars set at the appropriate distance,” says Boyle. “When handling individual panels, soft gloves should be worn and more than one person is required to move or lift any panel over 10 feet long, and that’s to protect it from bending. A forklift can be used to lift panels, but the forks have to be set at the maximum spacing.”
ABC does not use forklifts and strongly suggests customers not use them either. “We recommend using slings with a spreader bar, that’s what we use,” Viechnicki says.
“The most common thing with long panels, over 24 feet is when they try to pick them up in the middle,” Northen says. “You need that spreader bar. That’s probably the biggest ‘oops’ out there.”
Carrying panels by lifting in the middle can cause bending, kinking, or even cracking. Extra care is necessary when picking up panels by the end as well.
“You can do damage to long sheets by picking them up at either end,” says Croucher. “If you hold them wrong there’s a good chance they’ll kink in the middle. Long standing seam panels can’t be carried horizontally, they need to be carried vertically. It’s important with ribbed panels, but it’s especially important with standing seam panels. And when being carried, we recommend at least two people every 20 feet for standing seam panels.”
Cut panels may have sharp burrs that increase the chances of scratching paints or the panels themselves. Some companies have helped reduce this problem by cutting panels before they are formed. Pre-cut panels also contain burrs, but they are at least partially smoothed out during the roll forming process, when some coating will be smeared over the edge of the metal.
Some jobs may require a certain amount of field cutting. NamZAC says panels should be cut using straight blade shears, profile shears, nibblers, or hand snips. It is important that all jobsite cutting practices give a clean-cut edge without damaging the paint or metal coating. The shear blades should be kept sharp to minimize burrs. Shearing of prepainted steel sheets should be done with the critical (exposed) surface uppermost so that any small burrs are on the unexposed side. Never perform field cutting over the top of other painted products. If power cutting or drilling is required, the area around the holes and cuttings should be masked with tape of covered with rags to protect the paint from hot filings. Cutting with an abrasive disc or hacksaw, or burning through with oxyacetylene or similar torches should be avoided to prevent damage to the paint and metal coating.
Hot filings can also be a result of aggressive fastening. Viechnicki says improper fastening techniques lead to the most callbacks. The metal filings produced when fasteners are screwed into place leave a halo around the fastener if not swept off. “The metal filings are so hot, they stick in the paint,” he says. “We suggest sweeping off the filings, especially around the screw heads.”
Those filings, which are exposed metal, will not take long to rust. That rust will stain the painted surface. Metal filings, drillings, cuttings, and other metal debris, such as pop rivet stems and fasteners, should never be left on the prepainted steel surface. These particles should be removed from panels as soon as they are noticed and swept from the roof at least at the end of each day during construction.
Another recommendation includes avoiding walking on such particles. Rechecking panels a couple weeks after completed installation is also a good idea. Any remaining particles will have started to rust because of exposure to rain or dew and can be easily spotted. Removing those particles should only enhance the long-term appearance and performance of the panels.