Oil canning is a common issue with steel roofing and siding where large, flat metal panels show visible waviness or buckling, often described as a “wavy” or “dimpling” effect. This happens because thin, flat steel panels expand and contract with temperature changes, causing stress that results in stress-induced distortions. It can also be caused by improper panel installation, such as panels being fastened too tightly or unevenly, or poor panel alignment. To check for oil canning at home, look at the roof or wall from different angles in bright sunlight; the waves usually become more noticeable in direct light. You can also gently press on the panels to see if any slight movement or springiness occurs—steel should feel firm and secure. However, avoid pulling or pushing too hard, as excessive force can damage the panels or compromise fasteners.
If oil canning is persistent or worsening, calling a roofer is the best step since repainting or replacing panels may be needed to restore a smooth appearance safely. When speaking with a contractor, ask if they use panels with stiffening ribs or thicker gauge steel, which can reduce oil canning. Also, inquire about their fastening techniques to ensure they leave enough room for metal movement without loosening, helping maintain your warranty coverage. It’s important to confirm that any corrective work won’t void your roof’s warranty, as improper fixes can nullify manufacturer guarantees. A roofer can recommend the right materials and methods based on your climate, roof slope, and style, giving you peace of mind and a longer-lasting steel roof.