Oil Canning can be defined as visible waviness in the flat areas of metal roofing and metal wall panels. In technical terms, oil canning is referred to as elastic buckling (more commonly known as “stress wrinkling”). It can occur in any type of metal panels: steel, aluminum, zinc, or copper. For purposes here, all four terms shall be considered synonymous: Waviness, elastic buckling, stress wrinkling and oil canning. The degree of waviness can be difficult to measure, but may be apparent, especially under specific lighting conditions.
Generally the period and amplitude of the wave will become more pronounced as the panel width increases (flat portion of the panel) and/or the panel thickness decreases. Reflected light may make the oil canning more prominent at certain times of day.