What is an oil canning characteristic in metal roofing?

The concept of oil canning in metal roofing refers to the visible waviness or distortion that can occur in flat metal panels, particularly those that are large and span wide areas without ample support. This phenomenon happens due to fluctuations in temperature and pressure, which cause the metal to expand and contract. It can also occur as a result of installation techniques, where panels may not be adequately secured or allowed room for movement.

While oil canning can detract from the visual appeal of a roof, it is not necessarily an indication of poor quality materials nor is it a sign of rusting. Instead, it is commonly seen simply as a normal occurrence that can happen even when proper practices are followed. This understanding of oil canning helps roofing installers and homeowners to better appreciate the variances that can occur in metal roofing installation.