Building a home or commercial building is a huge financial undertaking. Naturally, you’ll want to be sure to make the most of your investment by extensively researching and planning, hiring skilled craftsmen, selecting high quality materials, and considering the “big picture.” One way to ensure your building’s roof will last for decades to come is to opt for a standing seam metal roof instead of a traditional asphalt shingle roof. While metal roofs are more durable than classic roof systems, they can still experience a phenomenon that impacts the appearance of the roof — oil canning. Luckily, there are steps you can take to prevent oil canning, starting from the very beginning of the building process. Learn more about oil canning, and how it can impact your seam metal roofing system.
What is oil canning?
Oil canning, otherwise known as stress wrinkling, is a cosmetic roof issue that can cause the panels to appear wavy or distorted. It presents itself as waviness, bulkiness, and an overall unsightly appearance on metal panels between standing seams. The severity of oil canning can differ based on temperature and lighting condition. While oil canning doesn’t impact the actual structural integrity of the roof or building, it can diminish the appearance of your new roof.
What causes oil canning?
Oil canning can occur with a number of commonly used construction materials, including steel, galvalume, aluminum, galvanized, zinc, copper and more. During the milling process, the rollers used to form coils and sheets can have gaps that prevent the equal distribution of stress within the panel. Oil canning can also be caused by inadequate spacing to allow for thermal expansion, poor handling, and metal clips that are too tight. Dark color panels are also more prone to displaying this visual phenomenon than lighter colors.
Other causes of oil canning
There are many factors that can contribute to oil canning, many of which can be carefully avoided at the very start of the build. It can occur early on in the flattening and coiling of the production process, in fact there are three instances during this process that can contribute to oil canning. These include full center stresses, wavy edge stresses, and camber stresses. During full center stresses, the sheet or coil is misplaced from the middle section, which can lead to ripples in the center of the panel. Wavy edge stresses occur when the edge of the sheet is misplaced from the edge of the metal strip, and camber stresses occur when the metal sheet curves or no longer lays flat.
Can oil canning be fixed?
Ultimately, oil canning cannot be fixed unless metal panels are fully replaced. This makes careful construction and prevention all the more crucial early on. However, the appearance of oil canning can also look different depending on the color of the panels, the time of year, the outside temperature, so it may look less severe at times.
How can it be prevented?
One of the best ways to prevent and avoid oil canning is by following metal roofing best practices, like hiring contractors with the proper training to ensure your roof is installed with the utmost precision and care. During the installation process, it’s important that each panel is aligned properly, and that contractors avoid overdriving metal fasteners as this can contribute to the wavy, uneven finish. Selecting high quality, thick material and choosing a light-colored and low-gloss finish for your panels can also be key to prevention, as these are known to reduce the appearance of oil canning. Using a rib roller can minimize the look of oil canning as well, and are available in a few different varieties including ribbed, v-ribs, bead, pencil, striated and more.
What should roofers consider while planning and installing the metal roof?
Whether you’re hiring professionals to tackle your metal roof or doing it yourself, one thing is certain — remaining diligent during every step in the installation process is vital to prevent oil canning. Ensure that all materials being used in the roofing process are dry, stored properly and in good condition before beginning the installation. Tension-leveled metal is considered optimal for metal roof installation, as it has already been stretched and cannot warp back to its original state. Transporters should be put in place to protect the panels. Using metal clips and fasteners is not only important for structural reasons, but can also help point out early signs of oil canning. Including backer rods can provide upright pressure that is also known to eliminate the possibility of oil canning.
While oil canning can certainly be an undesirable result of having a metal roof, it is quite common, and can be avoided with expert installation. ASMI can help you find the right tools, clips, fasteners and more to complete your roofing projects the right way. For more resources, information and to browse our full selection of top brands, give us a call.