Understanding oil canning in metal panels

By Metal Sales. 

Learn a few helpful tips to reduce oil canning in metal panels to provide homeowners with the beautiful roof they expect. 

While it will not negatively affect the structural integrity of a metal panel, it is important to be mindful of oil canning when helping homeowners settle on a metal roof. Oil canning is when a metal panel looks distorted, often creating a wavy or bubbled up look and is dependent on a variety of factors including color, roof angle or the type of finish.  

There are a few things that can cause issues, including: 

• Incorrect fastener installation 
• Uneven stresses at the fastening points 
• Not handling the metal correctly. Panels should not be carried flat or lifted by a single corner from a bundle or crate 
• Not installing the correct dimensions 
• Clips are too loose or too tight 
• Over driving fasteners 
• Uneven Substrate 
• Underlayment that is not flat 

The biggest concern that goes with oil canning is with the higher slope and high visibility projects.  

Those will be noticeable more than others. There are things that can help address it including the type of metal and thickness of the panel. 

A standing seam metal panel that is flat between the ribs is more likely to show oil canning than a ribbed metal panel. Selecting a standing seam panel with striations or minor ribs greatly reduces oil canning. 

A heavier gauge panel also contributes to lessening the effects. The lower the gauge number, the heavier the panel. A 24-gauge metal panel will be thicker than a 26-gauge metal panel. 

Ribbed metal panel profiles and a thicker gauge will help but realize that the price is typically higher and can increase the cost of the project. If you are looking for a lower cost solution, look at the color you choose.  

Choosing a low gloss or matte finish on metal panels can reduce reflectivity, therefore decreasing the visibility of oil canning. A darker color profile will typically show more waves and ripples than a lighter color. 

Fastening a 3/8-inch diameter foam backer rod under the center of each panel during installation can significantly reduce stress wrinkling.  

The addition of the foam strip creates a crown down the panel, which pushes any ripples out toward the outer edge where they are less noticeable. 

The installation crew plays an important role in making sure a roof is aesthetically pleasing. An experienced crew understands the importance of planning the layout and avoiding inducing stress which can inadvertently cause oil canning.  

The installation crew should know how to properly handle the metal and install backer rods to help reduce oil canning. 

Lastly, make sure you select a manufacturer that has trained technicians who understand the importance of handling and properly ensuring the equipment is maintained and calibrated before production begins. 

Oil canning is generally an aesthetic issue and is not a cause for rejection. By installing and handling correctly, oil canning can be greatly reduced. 

Original article source: Metal Sales