Oil canning is a common concern in the world of metal roofing and siding. It is essentially a moderate deformation or buckling of sheet metal, typically found on flat surfaces. This unwanted appearance of wavy or rippled lines can detract from the overall aesthetics of the building. Although oil canning is often seen as an undesirable aesthetic issue, it should be understood that it is a natural characteristic of all cold-rolled flat metal and should not be a reason for rejection. Despite the fact that many people find the appearance unappealing, it does not negatively impact the structural integrity of the metal or its ability to remain waterproof. In this blog post, we will explore the causes of oil canning and provide some possible solutions.
What is Oil Canning?
Oil canning, also known as stress wrinkling or elastic buckling, refers to the visible waviness or rippling that can occur in metal panels. It is more noticeable on flat or smooth surfaces and can be quite frustrating for those seeking a seamless and blemish-free appearance.
Jeff Haddock, AEP Span Technical Services Manager, mentions “Oil canning is caused by internal stresses within thin-gauge metals. These stresses can be introduced during the production of the coil and fabrication of the panels. Field installation techniques, conditions, and construction tolerances can also greatly impact the presence of oil canning.”
Common Causes
1. Thermal Expansion and Contraction: Metal expands and contracts with temperature changes, and if the panel is not properly installed or restrained, it can lead to stress in the panel and result in oil canning.
2. Manufacturing Imperfections: Variations in the manufacturing process, such as uneven tension in the metal or variations in the thickness, can contribute to the issues.
3. Improper Handling and Storage: Mishandling the metal panels during transportation, storage, or installation can cause distortion or dents, leading to unsightly appearances.
Solutions to Oil Canning:
1. Proper Installation: Following the manufacturer’s guidelines for installation is crucial to minimize the risk of an unsightly appearance. Proper fastening, spacing, and support are essential to ensure the panels are installed correctly.
2. Panel Selection: Choosing metal panels with thicker gauges, or choosing a panel with striations or ribs can help reduce wavy or rippling appearances.
3. Adequate Substrate Support: Ensuring the framing members are properly spaced and structurally sound to help minimize flexing.
4. Regular Maintenance: Conducting routine maintenance, such as cleaning debris and inspecting for any signs of damage, can help prevent any issues from worsening.
Remember, oil canning may not always be completely avoidable, especially in certain weather conditions or with extensive panel spans. However, by understanding the causes and implementing appropriate solutions, you can significantly reduce the occurrence and minimize the visible effects of oil canning on your metal roofing and siding project.
For more information, check out this great article from Metal Construction News. For more information on our metal roofing and siding products that are designed to minimize the appearance of oil canning, check out our striated panel options or contact our team of experts who will be happy to assist you.