Your roofing choice impacts the longevity, durability, and overall aesthetics of your building. You want a roof that lasts a long time and looks great for a long time, right?
Standing seam metal roofing and corrugated, screw-down metal roofing are two excellent choices, but which one’s best for you?
In this article, we’ll break down five key differences between these two types of roofing: fasteners, expansion and contraction, trims, seams, and thickness and paint. Let’s dive in and see what sets these metal roof types apart.
Key Differences
- Standing seam metal roofs feature hidden fasteners which protect against leaks. In contrast, corrugated roofs have exposed fasteners that are prone to weathering and can cause leaks over time, reducing their lifespan compared to standing seam – though both last well-longer than shingles.
- The average standing seam metal roof is made from slightly thicker steel. Both roof types that we install are painted with Kynar paint, which is guaranteed by the manufacturer for up to 35 years. Corrugated metal panels require more maintenance due to exposed fasteners, provide less weather-tightness, and are not suitable for low slope roofs.
- Standing seam metal roofs can last 60 years or more, and corrugated metal can last more than 40. While all metal panels are pricier than asphalt shingles, both types will last longer, look better, and perform more reliably than shingles, saving you money on maintenance, repairs, and replacements over their life.
Understanding the Basics
Before talking about their differences, let’s get you up to speed on what your two choices actually are, and what they look like.
Corrugated Metal Roofing Panels
Corrugated metal roofing — also called ribbed panels, ag panels, or agricultural panels — uses a simple design and approach to get you a durable and effective metal roof. It has a wavy look with exposed metal fasteners and has been a staple roofing material for a long time due to its affordability and low installation costs. However, corrugated metal panels are not suitable for low slope roofs.
It is quite literally a metal roofing panel that’s corrugated, which is a fancy word for something shaped into a series of ridges and grooves, with a wave-like pattern. The design makes the material stronger while maintaining its flexibility.
Standing Seam Metal Roofs
A standing seam metal roof is similarly composed of metal panels. However, standing seam panels have a sleek, modern look with hidden fasteners. These may also have ridges and grooves but always feature big seams that stand out, acting like the ribs of the metal panel to support it.
They tend to be a bit more expensive than corrugated metal roofs but also require less maintenance.
What’s The Difference Between Corrugated Metal Roofing and Standing Seam Metal Roofing?
Now that you’ve got the basics let’s get into the specifics.
Fasteners
The most obvious difference when considering the standing seam vs corrugated metal roof question is fasteners – how the roof is held in place. Corrugated metal roofing is held together by screws driven directly through the metal panels and secured (and sealed!) with neoprene rubber washers.
These washers create a watertight seal but do degrade over time. You can expect some to begin to degrade and fail at around 20-25-year mark, meaning you’ll want to inspect your roof or hire a professional roofing contractor to replace them once every two decades or so.
The issue is that these fasteners completely exposed to the elements.
Standing seam metal roofs, by contrast, are fastened with clips that attach to the roof deck with screws. The clips are hidden beneath the metal roofing, protecting them from the elements, and nothing is exposed. This design eliminates the risk of having leaks when the rubber washers deteriorate, simply because you don’t use rubber washers.
Thermal Expansion
Thermal expansion is when elements like metal panels expand with the heat and contract with the cold of seasonal or day-to-day outdoor temperatures. Metal roofing is particularly susceptible to temperature fluctuations because metal is a great heat conductor and, in this case, it’s always exposed to the sun.
Corrugated metal roofing can’t accommodate thermal expansion quite as well as standing seam because of how it’s secured. By pinning them down with screws, you effectively reduce the panel’s “wiggle room”, placing higher stress on the screws and nails.
Here at Rockland Builders, we’ve personally seen many cases where the stress has caused the fasteners to loosen and pop out over time. This in turn allows water to come in through the holes. This process takes decades, but it’s worth being aware of.
Meanwhile, the clips used to secure the panels of standing seam metal roofs allow them to expand and contract freely without stressing the fasteners beneath the flat metal panels.
This makes standing seam roofing superior in terms of structural integrity and leak prevention.
Trims
Metal roofing is not just one big sheet of metal. Many 3- or 4-foot panels have to come together somehow, and this is another area where these two roofing systems differ.
Standing seam metal roofs use interlocking trims with hemmed edges and offset cleats. The metal panels turn down and lock onto adjacent panels, creating a watertight connection. This design ensures the safety of the fasteners and reduces leak points.
In contrast, corrugated metal roofing panels are simply laid on top of each other and screwed to the roof where they overlap. This provides excellent weather-proofing, but unlike standing seam panels, corrugated metal roofs can’t fit together quite so tightly, meaning they can be a little more prone to structural decay over time.
Seams
A key advantage of standing seam metal roofs is their seamless design. We use a roll-forming machine to form our panels on-site, ensuring they’re the exact length required for the project, and that they don’t have any horizontal (perpendicular to the top of the roof) seams.
This not only makes them prettier and tidier but also minimizes potential leak points. A corrugated metal roof may have seams because of how the panels are formed. This makes them look a little less uniform, giving them a more industrial look.
Thickness and Paint
Our corrugated panels are made from 29-gauge steel.
Our standing seam metal roofs, on the other hand, are made from a thicker 24-gauge steel, not including the paint coating.
The thinner metal on your average corrugated metal roof makes it a little more prone to damage – though not much.
The additional thickness of standing seam roofs makes them sturdier and hardier, meaning they require less maintenance and can last for generations in the home.
Both our standing seam metal roofing and corrugated roofing coated with Kynar paint, which has a 35-year warranty. This incredible paint ensures that your roof’s look won’t fade over time, and it’ll also maintain its protective qualities for far longer than other siliconized products.
Choosing What’s Right For You
While we generally recommend standing seam roofs due to their superior durability and, for many, enhanced aesthetics, they do tend to be a little pricier than the alternative.
The great news is that, as we’ve mentioned, standing seam roofing has lower maintenance and won’t need any adjustments for decades!
Metal roofing is more expensive upfront than asphalt shingles and other roofing systems. If you’re going to make the investment, why not make sure you won’t have to redo your roof ever again?
All-in-all, a standing seam roof is arguably the best of roofing materials, and when you compare standing seam to asphalt shingle roofing, the choice is clear.
Interested in a New Metal Roof?
Standing seam roofing with hidden fasteners will resist severe weather and can last for 60 years or more when installed correctly.
Rockland Builders is Allentown’s top choice in standing seam roofing installers. We utilize advanced metal rollers to custom-form panels on-site and ensure they fit your roof perfectly. We offer a variety of metal roofing and siding options, suitable for all home styles, commercial building applications, the application of solar panels, and more!
If you have questions about metal roofing types, minimum roof slope, standing seam system, or WHATEVER – give us a call to chat or schedule a free consultation today.
