Oil canning, sometimes called elastic buckling, occurs when the metal panels on a flat metal roof appear distorted. While it happens in any type of metal, including aluminum, steel, zinc, or copper, it’s primarily a visual issue that doesn’t affect the structural integrity of the roof. Here are the causes of oil canning and tips for prevention. 

What Causes It

Oil canning commonly occurs in standing seam roof systems, or metal roofs that have raised seams. The roof’s color, finish, and pitch can create a visibly wavy effect when observed from specific angles. For example, metal panels with dark colors and a high-gloss finish have a higher chance of appearing warped than light-colored panels with a low sheen. The distortion will also appear and disappear with the angle of sunlight on the roof.

How a metal roof is installed also plays a significant role in creating oil canning: possible causes include over fastening materials and using panels with a wide width. Temperature variations can also contribute as both extremely hot or cold weather can make panels appear wavy.

How to Prevent It

Before installation, installers should verify that the deck beneath is level. They can also strengthen the metal by adding ribs and using thicker panels.

Consider reducing the width of panels and placing a backer rod underneath each one. For best results, create a crown by placing a 3/8 inch foam rod down the center of each panel. This lessens the visibility of ripples by pushing them to the panel’s edges.

Using a quality metal manufacturer can also make a significant difference. In addition, installers should always follow the guidelines from the material’s manufacturer when applying cleats, which allow for the expansion and contraction of the roof. 

If you need high-quality metal materials for a roof installation, H & H Metal Products LLC has supplied Tennessee’s metal roofing contractors with dependable panels for 30 years. They frequently inspect their equipment for poorly adjusted or worn roll formers to make sure problems such as oil canning are reduced. Call (731) 925-1922 to ask about your project or visit them online to learn more about their services.