Why do some metal roofs look wavy?
Oil canning is the waviness of a metal panel and is an inherent characteristic of light-gauge, cold-rolled flat metal products. It is a makes metal panels look wavy or somewhat distorted, especially in the broad, flat areas of a metal roof or wall system. Oil canning can occur with any type of metal material used in construction, because all metals have a memory and the material is always trying to revert to its original form. The severity of the waviness can vary somewhat depending on factors such as color, thickness and finish of the metal, sometimes even the time of day, or time of year can affect the amount of waviness you are seeing. For these reasons there is no real scale for measuring the severity of it.
The good news is if it does occur, it’s just a surface-level issue. The structural integrity of the panel is not affected. Therefore, nearly all warranties don’t include Oil Canning as a claim because there isn’t anything technically wrong with the material or the system that would cause the roof to fail. However, there are known causes that can contribute to the Oil Canning, as well as ways to minimize the chances of it happening. Below we have listed some things that could be contributary to Oil Canning if you are not careful.
Stresses during the production process- This is one of the reasons we manufacture our own custom metal, so we can have control of the production process. It allows us to provide a better-quality product to our consumer. The quality of our roofing and siding is second to none. Manufactured from 29 gauge steel.
Stresses during roll forming and slitting- Something to consider when choosing your contractor. They say you get what you pay for, and when looking at bids from different providers you need to think about the quality of workmanship they will provide you, and their experience in handling and forming the metal.
Color and gloss type- Although this doesn’t have any bearing on whether Oil Canning will occur, it will either enhance or mask the amount of waviness you see depending on the style you choose.
Incorrect fastener installation- Again this goes back to the contractor you choose, if the metal is installed incorrectly, or the way it is fastened is incorrect it can add to the wavy appearance.
Misalignment of the panels- The Oil Canning effect that is perceived can be somewhat controlled by the correct alignment of the panels. Yet another thing to consider when choosing the right contractor for the job.
It is important to keep in mind that Oil Canning is not always preventable, sometimes due to the structure of the building it is inevitable. Remember that if it does happen it has no bearing on the structural integrity of your roof. However we know that having a system that is aesthetically appealing for years to come is important. That is why at Metal Exteriors it is our top priority to provide the highest quality metal to the contractors that partner with us. We hope this helps you to make an informed decision when choosing the materials and look you desire and a contractor you can trust.