What is Oil Canning on a Metal Roof? (And How to Prevent it)

Are you considering a metal roof for your roof replacement?

You may have heard a lot about metal roofs. They offer a clean look and while they’re a pricier option than shingles, they can last up to 50 years! This makes a metal roof well worth it for a homeowner who doesn’t want to deal with roof repairs or replacements for a long time. Because metal roofs are more costly than traditional asphalt shingles, homeowners tend to be skeptical about the potential issues that can come with having a metal roof installed on their home. 

And while over the last 39+ years we’ve seen metal roofs passed down from generation to generation, it’s unfair to say they don’t have their problems. And when it comes to aesthetics, oil canning is the most common culprit. In this article we’ll discuss what oil canning is and how it affects your roof’s ability to withstand the elements. 

Let’s talk about it.

What is Oil Canning on a Metal Roof?

Oil canning refers to the visible waviness that can develop over time on metal panels, especially in large, flat sections of a metal roof. Despite the name, oil isn’t part of the process that creates a wavy look on your metal roof. The term is derived from the old days of storing oil in metal cans, which would flex or pop when pressure was applied, creating a similar wavy effect to what you may notice on metal surfaces today. In metal roofing, oil canning can be caused by a number of factors, not just pressure.

Most commonly oil canning on a metal roof is caused by:

• Thermal expansion and contraction
• Uneven roof deck or substrate

This waviness is most often seen when the sunlight hits a roof in the right direction. And while it alters the look of your roof, oil canning does not diminish the quality or longevity of your metal roof.

So, if you’re interested in a metal roof for its durability and longevity, oil canning is not a problem in terms of metal roof performance. However, while it can be inevitable, there are some ways to mitigate the potential for oil canning on your metal roof.

How to Prevent Oil Canning on Your Metal Roof

Because this issue is common, often metal manufacturers require homeowners to sign an acknowledgement form.

This form indicates that they’re aware of oil canning and the potential aesthetic changes it can cause.

As stated in the acknowledgement form, striated metal panels can prevent or diminish the look of oil canning on your metal roof, making a more striated metal roof style appealing to homeowners worried about oil canning. Striated panels have designs between the ribs, which limits the flat surface that can become warped. Not only that, but requesting a thicker metal material can help. Thicker metals are less likely to flex or distort, reducing the chances of oil canning.

Straited Metal Panel

Non-striated Metal Panel

Is a Metal Roof Worth it Despite Oil Canning?

Often roofers boast that a metal roof is the ideal roofing solution. Metal roofs last a long time, they are visually appealing, and they’re a lower maintenance option than traditional asphalt shingles. But if the look of your metal roof is a concern, it’s important to note that oil canning is a possibility. 

If functionality and durability are your top concerns, you may come to find that a metal roof is still worth it despite oil canning. On the other hand, if the aesthetic look of a metal roof is what made you want one in the first place, oil canning may deter you from choosing metal. Ultimately, your decision is based on what your personal goals are for your home. 

And if you find yourself somewhere in the middle, don’t be discouraged. Your roofer may be able to help you achieve the look you want and offer suggestions to mitigate the appearance of oil canning on your roof. We at Linta Roofing are happy to help you make this difficult decision by offering you transparent answers to your roofing questions. So, don’t hesitate to reach out and we’ll have an expert contact you to discuss your options!