There are many reasons to choose a metal roof: They offer incredible durability and exceptionally long lifespans, all while being eco-friendly thanks to their recyclability. One reason that doesn’t get talked about often enough is the beauty of metal roofing; modern metal roofs look incredible, and come in a variety of colours and textures to match your aesthetic needs.

One aesthetic problem that metal roofing owners may face is oil canning, a visual phenomenon that makes metal roofing look wavy, rippling, or distorted. In this article, we cover what oil canning is, why it occurs, and how to minimize and prevent it.

What Is Oil Canning?

Oil canning is a cosmetic characteristic found in some metal roofing; it’s characterized by the appearance of waviness, rippling, warping, and other distortions, typically found on the flat sections of a metal roof.

The most important thing to know about oil canning is that the phenomenon does not mean the structural integrity of your roof is at risk; though there are physical causes for oil canning (which we’ll discuss below), the consequences are purely visual.

Oil canning is most noticeable in direct sunlight; it’s also more noticeable from shallow angles or from far away. 

What Causes Oil Canning On Metal Panels?

One of the reasons that oil canning is so common on metal panels is that there are so many different things that can cause canning. Here are a few:

  • Thermal expansion and contraction. As metal heats up, it expands; as it cools, it contracts. When those forces have nowhere to go, it can lead to the internal stresses that cause oil canning; this is more likely to occur if the panels cannot move as they expand and contract. 
  • Manufacturing. Cold-rolled metal “remembers” its original shape, and it’s always trying to get back to that shape. This will cause the metal to move and warp slightly over time, which can cause oil canning.
  • Improper handling and installation. Oil canning can begin when transporting long panels; if they are carried incorrectly, the panels may bend in the middle. Misaligning panels, not allowing enough space for thermal expansion, overdriving or angling fasteners, and issues with the roof deck can all also increase the likelihood of oil canning. 

How To Minimize Oil Canning On Your Metal Roof

Choose Heavier-Gauge Metal

Heavier-gauge panels are less prone to oil canning because their thickness lends them rigidity; this stiffness makes them much more resistant to the small deformations that can cause oil canning. 

Select Standing Seam Panels

Standing seam panels feature hidden fasteners and clips to allow for thermal expansion and contraction. Allowing the panels to shift naturally reduces the pressure they exert on themselves, limiting oil canning. 

Use Striated Or Ribbed Panels

Ribbed panels are stiffer than completely flat panels; this stiffness reduces the risk of oil canning. The ribs also reduce how much light is reflected from the panels, which makes any oil canning harder to notice. 

Work With Experienced Installers

Experienced installers will know how to handle the metal panels, how to prepare your roof properly, and how to install and fasten the panels without increasing the risk of oil canning. 

Can Oil Canning Be Eliminated Completely?

The risk of oil canning cannot be eliminated completely when using cold-rolled flat metal panels, but proper handling, expert installation, and higher gauge panels can also lower the chances of oil canning appearing on your roof. 

Why Choose IroSteel Metal Roof Panels

IroSteel provides homeowners and business owners in Manitoba with premium quality metal roofing; we’ve been doing so since 2017. All of our metal roofing panels are manufactured in-house, right here in Winkler, using North American Galvalume steel.

Want quality metal roofing panels that limit the risk of oil canning? Choose IroSteel. 

FAQ On Oil Canning

Is oil canning on a metal roof a structural problem?

No, oil canning is an aesthetic concern. The structural integrity of your roof will not be compromised if you see oil canning. 

Does oil canning get worse over time on a metal roof?

Oil canning can get worse over time, especially if issues like overfastening or a lack of room for thermal movement are not resolved. Worried that oil canning may have been caused by poor installation? Call IroSteel. 

Can I fix oil canning after my metal roof is already installed?

You cannot fix oil canning; it’s a problem inherent to the panels, though the look of oil canning will change depending on angles and lighting. You can replace panels that are severely affected by oil canning, however. 

Does the colour of my metal roof affect how visible oil canning is?

Colour is not a significant factor in the visibility of oil canning. Dark coloured roofs, however, can be more prone to thermal expansion and contraction, which can make it more likely that oil canning will occur.

When it comes to visibility, finish is more important than colour. Glossy finishes reflect light, and that makes oil canning more noticeable. Opting for matte and textured finishes can reduce the appearance of oil canning. 

Worried About Oil Canning? Get Your Free Quote From IroSteel 

We manufacture all of our metal panels in-house, so we take every precaution to minimize the risk of oil canning. We recommend either our Standing Seam Roofing or our Snap-Lock 150 panels; both are excellent choices for strong, long-lasting metal panels with a lower chance of oil canning.

Looking for a metal roofing supplier in Manitoba? Choose the team that manufactures in-house to prevent oil canning; choose IroSteel.