Discover why Oil Canning occurs, what to look for during installation, and how to minimize the chance of it happening.
What is Oil Canning?
Oil canning is a visual phenomenon that makes metal panels look wavy or somewhat distorted. Especially in the broad, flat areas of a metal roof or wall system.
The severity of the waviness varies quite a bit depending on the irregularities of the roof deck. And, like the colour, finish, time of day, time of year, or even the angle you are viewing the metal roof.
Oil canning is an aesthetic issue, and it doesn’t affect the structural integrity of the roofing system.
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What Causes Oil Canning?
The causes can vary; here are a few reasons your metal roof may experience oil canning.
During installation, fasteners can be overdriven, driven in at the wrong angle, or even the wrong clip systems can be used. The panels themselves can also be misaligned. Improperly installing the metal panels can lead to uneven stresses.
Uneven Roof Decking:
An uneven roof decking or substrate can also lead to oil canning, which can cause slight contours, resulting in more visible distortion.
Improper Storing or Handling:
Before installation, it’s critical to ensure your materials are handled and stored with care. Installers should always carry metal panels perpendicular to the surface to prevent bowing. Always follow the storage and handling instructions.
Be sure you’re hiring a roofing contractor who has worked with metal before installation to avoid any poor installation that could result in oil canning.
Stress During Production/Milling Process:
When metal companies produce metal panels, they use rollers to form the sheets and coils. Due to the small gaps within the rollers, there can sometimes be an uneven or improper stress distribution.
Inadequate space allotted for thermal movement
When you restrict the expansion and contraction needed for proper thermal movement of a metal panel, you can run into an oil canning issue. Oil Canning happens very often when panels are double pinned at the edges, which restricts the centers from moving during thermal expansion/contraction causing stress on the metal.
Tips for Reducing Oil Canning
Before the metal panel installation, you can take some steps to minimize oil canning:
- Choose a Thicker Gauge Metal: When choosing the details of your panels, go with a thicker gauge that is more rigid (gauge refers to a metal panel’s thickness). Choosing a thicker metal makes it more difficult for the metal to move and eventually give in.
- Add Striations: These are a series of ribs, waves, or ridges added to metal panels to minimize the look of oil canning. They can help keep standing seam and other flat panels looking their best.
- Choose Textured or Low Gloss Finishes: When choosing the finish you’ll use on your metal panels, select matte or low-gloss finishes. These finishes reduce the reflectivity and make any oil canning less visible. Choosing textured matte finishes will also help diminish the looks of waviness.
- Hire Expert Installers: Oil canning commonly results from poor or faulty installation. Ensuring you hire a team of installers with metal roofing experts can reduce the chance of oil canning occurring.
- Choose Narrower Widths: Because oil canning is more visible in the broad, flat areas of the metal panels, using narrower widths can minimize the look of this issue. In addition, with less space between the metal panels’ widths, oil canning will be less visible.
When considering metal roofing for your Florida home, it’s essential to understand that there is no 100% guarantee that your metal roofing panels will not experience oil canning. Because it’s the nature of metal to try to revert to its original form. This issue is completely aesthetic-related.
Following the tips discussed in this article, you’ll have a better chance of reducing this issue before it starts.