What is oil canning?
When buying a metal roof, one of the terms you might hear during the process is oil canning. Oil canning is something you see when a metal panel appears wavy or distorted.
The amount of waviness can be dependent on many things including color, finish, angle of viewpoint and even the time of day or year. Oil canning does not affect the structural integrity but it’s not what people have in mind when purchasing metal.
There are a few things that can cause issues, including:
- Stresses during the roll forming including poorly adjusted or worn roll formers
- 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 outer edge where they are less noticeable.
The installation crew plays an important role in making sure your 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.
About Metal Sales
Metal Sales Manufacturing Corporation is the premier nationwide provider of metal panels for the construction industry. Metal Sales works with architectural specifiers and commercial construction professionals to create inspirational design solutions. With the industry’s largest and most knowledgeable sales and technical support team, Metal Sales has the expertise to address today’s challenges in high-performance, sustainable and Net-Zero building. Metal Sales has outreach around the world. Delivering outstanding roof, wall and fascia metal panels from its 21 facilities throughout the U.S.