Exposed Fastener Vs. Concealed Fastener Metal Roofing: What is the Difference?

How long do screw last on metal roof

When considering a metal roofing system, understanding the key differences between exposed fastener Roofing (such as Tuff Rib) and Concealed Fastener roofing (such as Standing Seam) systems is instrumental in making your decision.

The Most Obvious Differences

Exposed fastener panels are fastened with visible screws, while standing seam is fastened with hidden clips or screws. The fasteners chosen for through fastened panels are galvanized or zinc plated, with a neoprene or EPDM rubber seal capped by a metal washer. These screws are painted to match the roof. We recommend using the Long-life Fastener with a higher longevity rating from the screw manufacturer than standard roofing screws.

There are two ways to fasten a standing seam panel, a fastening flange(AKA Nail-Strip) which is screwed into, or a clip that hooks over the rib and is fastened into. Then next the panel is snapped or seamed over the previous panel depending on the manufactures specifications.

Appearance

exposed fastener panels typically look similar to a board and batten design, with trapezoidal major ribs often at 9″-12″ apart, and minor ribs between the major ribs on most profiles. Some profiles, such as 5V-Crimp, provide a thin seam style that is closer to the look of standing seam. TuffRib is the most common panel in this category, with it being the most common residential roofing alternative to asphalt roofing products.

Standing seam panels give a modern thin seam look, with narrow ribs often at 14″-16″ apart (depending on the profile), and flatter spaces “pans” between the ribs. The pans may be striated with gentle low profile striations, have minor ribs, or be completely flat between the ribs. Striations are the most common as they reduce or eliminate oil canning (visible waviness on the flat surface of the pan).

Installation

Exposed fastener panels, like TuffRib, install faster than standing seam, with a quickly installed coverage width of 36″. Trims also install quite fast.

Snap-together standing seam (hidden clip or hidden nail-strip) systems can be installed fairly quickly, Trims however, are designed to hide screws, which takes somewhat longer to install compared to through fastened panels trims.

Longevity

Exposed Fastener and standing seam roof systems both offer long warranties typically at 40 years for paint and 30 years for fade and chalk.

On exposed fastener panels, screws should be inspected – typically after about 15-20 years. Often little to no maintenance is needed. Some screws may need tightened up, or in extreme cases you may have to replace screws.

The key benefit of the hidden fasteners on standing seam is they never need to be inspected or replaced – standing seam is maintenance-free. Even after the 40-year warranty, you’ll have a strong, long-lasting warranty. You may consider repainting it somewhere near the 50-year mark, but hidden fasteners ensure a permanent roof solution.

Finishes

Both exposed fastener and standing seam systems come in a wide variety of colors – exposed fastener about 17 and standing seam about 40. Both styles can also come in non-painted Galvalume, with a 25-year warranty being very typical.

Gauges

Residential exposed fastener panels are often available in a 29 gauge or 26 gauge thickness (the lower the number the thicker the metal). Commercial exposed fastener panels are often available in a 26 gauge or 24 gauge thickness.

Standing Seam panels are often available in a 26 gauge or 24 gauge thickness. Some ultra-heavy profiles may even come in a 22 gauge thickness in commercial standing seam profiles.

In Summary

To sum things up for our residential clients, TuffRib an exposed fastener system is the most comparable pricewise to asphalt roofing products but is definitely more durable with a class 4 impact rating. We will only install Long-Life fasteners with this system, as we believe this give the customer the most value for the price.

Standing Seam, is the most worry-free of all of the metal roofing systems since all the fasteners are hidden from the elements. This gives you peace of mind for generations to come. However the thicker gauge material, along with more tedious installation practices does make this system a long term investment.

I know this a lot of information, but if you think of any questions we have failed to address, feel free to reach out to us at [email protected] or call our main office at 864-610-2176 for additional help.