Metal roofs are becoming increasingly popular in both the commercial and residential realms for many reasons. They are durable, long-lasting, energy efficient, and sustainable, and can even add curb appeal and value to your property. When researching this roofing style, however, you may have come across the phrase, “oil canning metal.”
But what is oil canning? Whether it’s copper, steel, or something else, oil canning is something you should know about when considering a metal roof installation. In this article, we break down exactly what oil canning is, and share what you need to know about metal roofing systems.
Table of Contents
– Oil Canning Metal Roofs: What Is It?
– Standing Seam vs. Screw Down Metal Roof
– Expansion Capacities
– Maintenance
– Longevity
– Metal Roof Installation
Oil Canning Metal Roofs: What Is It?
So, what is an oil canning metal roof? Oil canning is a characteristic that affects cold-rolled metal products. It’s a visible phenomenon that makes the metal panel look wavy or distorted. This can happen to any type of metal material used in construction such as steel, copper, zinc, and aluminum.
On the bright side, oil canning is a surface level issue, and doesn’t impact the integrity of the metal roof itself. There are a few things that can cause oil canning including stress imposed on the metal itself, uneven roof decking, and incorrect fastener installation, just to name a few. This is just one reason why it’s so important to hire a roofing contractor you can trust to get the job done.
Standing Seam vs. Screw Down Metal Roof
Pictured above is a standing seam metal roof
Now that you know what oil canning metal is, let’s discuss the different metal roof types and how they’re affected. When choosing a metal roof system, you will decide between a standing seam metal roof and a screw down metal roof. A screw down metal roof won’t experience oil canning, as there are too many ribs, but it’s common on standing seam roofs.
When standing seam roofs are installed, your roofer may fasten the metal panels together too tight. This means that the metal can only expand longways and not sideways, which can lead to signs of oil canning. When this happens, your roof will have a bubbly appearance, giving your metal panels a wavy look.
Again, oil canning doesn’t cause any problems as far as your roof’s functionality goes, but it can create a look that many homeowners don’t like. If curb appeal is top priority when it comes to your new roof replacement, just know that oil canning is a potential problem for your standing seam metal roof. With that being one of the only downsides of this roofing type, let’s discuss three advantages of installing a standing seam metal roof over a screw down roof.
Expansion Capacities
Any metal roof is going to go through thermal expansion. When metal is hot, it expands, and when it is cool, it contracts. While both a standing seam and screw down metal roof will go through thermal expansion, a standing seam metal roof expands and contracts more freely.
Standing seam metal panels are fastened under each seam with clips so that the metal panels can essentially glide back and forth. This means it can expand and contract freely when going through thermal expansion. However, a screw down metal roof is secured with screws through the metal itself, leaving less room for it to expand and contract freely and naturally.
Over time, a screw down metal roof will need to have the screws replaced with larger ones. This can result in leaks if left untreated. With that being said, we do not recommend a screw down metal roof over a heated living area, due to its lack of expansion capabilities.
Maintenance
Oil canning metal aside, standing seam metal roofs require less maintenance than screw down metal roofs. It’s important to note here that every roof, no matter what material is used, will need regular roof maintenance to ensure optimum performance and longevity. So, while both types of metal roofs will require some maintenance, there is virtually no maintenance required on a standing seam roof after installation.
You will still want to hire a contractor to come out and check roofing components, like the flashing around your roof penetrations, for example. Aside from that, cleaning is the only other maintenance that’s needed and recommended. This is a huge benefit of standing seam versus screw down metal roofs.
As previously mentioned, the metal panels on a screw down roof cannot expand and contract naturally. This causes pressure over time, and can lead to the screws causing the washers to expand, creating leaks and the need for regular roof maintenance. A roofer will need to come out every 5-10 years to replace the screws before it becomes a bigger, and costlier, problem.
Longevity
Oil canning metal may be common in standing seam metal roofs, but they last longer than screw down metal roofs. In fact, they are one of the most durable roofs on the market. This is crucial for homeowners in the market for a new roof, as purchasing a new roof is a large investment, and you want to be sure you’re getting the most years out of it.
And here is another reason why it’s so important to hire a vetted and experienced roofing contractor to do the job. As long as your roof is properly installed with adequate attic ventilation, your standing seam metal roof should last about 30 years. Under the perfect conditions, a standing seam metal roof could last for up to 50 years!
When you compare this to a screw down metal roof, a properly installed one should last about 20 years with no maintenance if it’s properly installed. When performing regular maintenance, however, you may be able to get 30 years out of your screw down metal roof investment. If longevity is a high priority on your metal roof replacement checklist, a standing seam roof is the way to go.
Metal Roof Installation
While oil canning metals is something to be aware of, a standing seam metal roof is still a wonderful investment. They look great, last long, are durable, and require little maintenance. Plus, there are things you can do to avoid this happening to you.
The best way to help prevent oil canning is by hiring a reputable contractor to properly install your standing seam metal roof. A knowledgeable and experienced roofer knows the installation process, and what it takes to ensure your new metal roof looks good and lasts as long as it should.
Elite Exteriors is the Southeast’s premier resource for unparalleled service, craftsmanship and quality. And it’s all backed by an unprecedented lifetime labor and materials warranty! Not only that, we offer NO-COST initial consultations and inspections. For more information, give us a call today at 470-350-3024, or click here to fill out an online form.