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Review of Metal Roof & Wall Panel Profiles Offered by Sheffield Metals

The best panel profile for your metal roofing or wall system project is dependent on the building type, the roof's slope, and many other factors that you might not have considered.


It’s true: Many standing seam metal roofing profiles offer a similar look to one another.

Beneath the aesthetic features of profiles are where the real differences tend to be, most of which revolve around the seam, how the panels are attached or secured to the roof deck, and how well each one performs in severe weather circumstances.

In other words: The panels may look the same, but could have different warranties, slope requirements, testing, roof deck assembles, and so on.

Here at Sheffield Metals, we offer many different panel profile systems, details, and options to choose from. We believe that it’s important to review some of our most popular profile choices to inform you of some of the pros and cons associated with each specific one.

In this article, we are going to go into more detail for these profiles:


Panel #1 – SMI 1.75” Snap-Lock

Panel Type: Standing seam

Panel Seam: Snap-lock

Panel Width: 16” aluminum | 18” steel

Seam Height: 1.75”

Panel Material: 22 - 24 gauge min steel | .040 aluminum

Panel Surface: Smooth | Embossed optional

Panel Clip: Required per engineering

Minimum Slope: 2/12

Substrate: Plywood, b-deck, b-deck w/ISO

Compatible S-5! Clamp: S-5-S, S-5-S Mini, S-5-U, S-5-U Mini


  • Engineering available – One reason the SMI 1.75” Snap-lock is so popular is that it’s engineered, tested, and proven to perform on numerous roof deck assemblies (plywood, b-deck, and b-deck w/ISO) with different materials (steel and aluminum).
  • No seaming required – With snap-lock profiles, panels have male and female legs that snap together after being rollformed, so no labor-intensive mechanical seaming is needed.
  • Installs faster than mechanical lock – Since no mechanical seaming is required, it takes less time to install this snap-lock profile than it would for a mechanically seamed profile.
  • Easier panel replacement – Repairing or replacing a panel is relatively hard with any roofing system, but snap-lock profiles make it a little easier because panels can just be un-snapped and snapped back together with the new/repaired panels.
  • Weather-tight warranty approved – One of the most significant reasons this profile is so popular is because it qualifies for our weather-tight warranties, including limited weather-tight warranties and no dollar limit weather-tight warranties, which is why this profile is a popular choice for commercial applications.
  • Popularity in the roofing industry – 1.75” snap-lock profiles are some of the most specified profiles in the metal roofing industry, no matter what company’s profile is used. This profile makes a great option for fulfilling any 1.75” snap-lock requirements.



  • Not available for slopes below a 2/12 – In general, snap-lock profiles should not be used for roof pitches of 2/12 or below, and the SMI 1.75” snap-lock is no exception. Flatter pitches don’t allow water to adequately drain, which can lead to premature degradation, color changes, and the overall failure of the roofing system.
  • More industrial look – This profile with the wider seam is considered to have a more industrial look, which tends to be less of an appeal for residential applications.


Panel #2 – SMI 1.5” Mechanical Seam

Panel Type: Standing seam

Panel Seam: Mechanical

Panel Width: 16”

Seam Height: 1.5”

Panel Material: 22 - 24 gauge min steel | .032 to .040 aluminum

Panel Surface: Smooth | Embossed optional

Panel Clip: Required per engineering

Minimum Slope: 2/12 | 1/12 (based on project conditions & inseam sealant application – STEEL ONLY)

Substrate: Plywood, b-deck, b-deck w/ISO

Compatible S-5! Clamp: S-5-E, S-5-E Mini, S-5-S, S-5-S Mini


  • Available for use on lower slopes – Mechanical lock systems are the preferred choice for use on lower sloped roofs. For the 1.5” Mechanical Seam profile, it can be installed on a 2/12 roof and even lower (down to 1/12) if inseam sealant is applied between steel panels.
  • Less expensive than 2” mechanical profiles – The 1.5” Mechanical Seam is less expensive when compared to any 2” mechanically seamed profile because less metal material is required to complete the 1.5” seam folds (single or double lock).
  • Thinner, low profile seam – Some snap-lock profiles are considered “bulky” because of the larger seam top, but mechanical seams have a thinner seam that is more narrow and low-profile.
  • Weather-tight warranty approved – Like the 1.75” Snap-lock, the SMI 1.5 Mechanical Seam also qualifies for our weather-tight warranties, including limited weather-tight warranties and no dollar limit weather-tight warranties.
  • Engineering availability – This profile has been tested and engineered for multiple materials (steel and aluminum) and deck assemblies (plywood, b-deck, and b-deck w/ISO), which means we know it will perform well in stressful weather conditions.
  • Popular in residential and light commercial applications– This profile is common for both light commercial and residential structures because of its superior performance, lower cost, and clean look.


  • Takes longer to install Mechanically locked profiles are notoriously more labor-intensive because once the adjacent panels are put together, the legs need to be seamed together either using a hand seamer or a mechanical seaming machine. This is why the 1.5” Mechanical Seam may take longer to install, which may increase the cost.
  • Harder to replace a panel – Because the mechanically seamed panels can’t be separated without using tools to unseam the entire length of the panel, it’s much more difficult to repair or replace damaged panels one at a time.
  • No open framing – This particular panel profile is not suitable or recommended for use on open framing applications.


Panel #3 – Sheffield Metals 1.0" FF Snap-lock

Panel Type: Standing seam

Panel Seam: Snap-lock

Panel Width: 16”

Seam Height: 1.0”

Panel Material: 22 - 24 gauge min steel

Panel Surface: Smooth | Embossed

Optional Panel Clip: None

Minimum Slope: 3/12

Substrate: Plywood

Compatible S-5! Clamp: S-5-N, S-5-N Mini, S-5-S, S-5-S Mini



  • No clip required – Clips cost money, especially if they’re engineered. The SMI 1.0” FF Snap-lock does not need a clip to be fastened down to the plywood deck, as the fasteners hold it down via slots in the male leg.
  • Cheaper – In general, fastener flange profiles are the more economical option for standing seam metal roofing. In addition to not having to pay for clips, it’s also easy to install and doesn’t require seaming
  • Quick installation – Like a snap-lock profile, fastener flange profiles are quicker to install because seaming is not needed and once the panels are fastened down, the panel legs snap together.
  • Looks like a standing seam metal roof – Standing seam metal roofs are expensive, especially true standing seam profiles such as mechanical and snap-lock profiles. Fastener flange profiles offer the same concealed fastener look, but they don’t utilize clips, which can lead to metal roofing problems in the future.



  • No engineering or weather-tight warranties – The SMI 1.0” FF Snap-lock is not offered with engineering, meaning it doesn’t qualify for weather-tight warranties of any kind.
  • Panels can rip easily around the fastener – With fastener flange profiles, your roof or your customers’ roof is only being held on to the structure by a fastener head and a 24 gauge slot. If the panel is exposed to the right amount of force, the metal can rip away from the fastener head, come loose, or even detach from the roof.
  • Panels are pinned – This fastener flange panel system is pinned, or directly attached to the roofing structure (without a clip). Pinned metal roof systems limit expansion and contraction needed for adequate thermal movement, which means there are stresses added to the metal that can lead to oil canning and other metal roofing problems.
    • To help remedy some of the issues of pinning, use a clip relief rib roller or ultra-low profile fasteners to avoid dimpling. (Keep in mind: Ultra low profile fasteners have even less of a fastener head to keep the panels attached.)
  • Uneven deck concerns – This profile is harder to install over an uneven deck because it’s pinned directly to the structure. Plus, if the deck is uneven or out-of-plane, the metal will take the form of the roof deck a lot more than a clip system will.
  • Shorter panel length – Due to the pinning and thermal movement concerns, the panel length is limited with a maximum length of 25 feet.
  • Sharp edges – The panel slots on the SMI 1.0” FF Snap-lock tend to have sharp edges that can tear the underlayment during and after the installation if not correctly handled.
  • Clamp acceptance issues – Fastener flange seams are known to not always accept clamps used for snow retention, solar panels, and other mounted products.
  • Snapping difficulties – After the fasteners are attached through the slot, the panel legs still need to be snapped together, which can sometimes be difficult and time-consuming.
  • Rollforming distortion – While not always the case, this profile can distort over time if rollformed in a machine where the drive and forming rollers aren’t separate.


Panel #4 – Sheffield Metals 1.0" FWP Flush Wall & Soffit

Panel Type: Wall / Soffit

Panel Width: 12”

Seam Height: 1.0”

Panel Material: 22 - 24 gauge min steel

Panel Surface: Smooth | Embossed optional


  • No clips required – For the SMI 1.0” FWP Flush Wall & Soffit profile, you do not need to purchase clips to install the panels.
  • Versatility – This profile, as indicated by the name, can be used as a wall or a soffit panel. Plus, it can be formed with or without perforations to be used as a soffit panel.
  • Engineering available – This profile has been tested and proven to perform in extreme weather environments, which is why it’s offered with engineering details.
  • Available for weather-tight warranties – Weather-tight warranties, both the limited and no dollar limit, are offered with this profile if the installer adheres to our provided installation details.
  • Reveal available – SMI 1.0” FWP can be installed with a panel reveal, or space between the panels, of 0” to 3” in .5” increments, or it can be flush.


  • Non-engineered reveal – While including a reveal on your wall panel system makes for a nice aesthetic look, the downside is that any kind of reveal is not engineered or approved for weather-tight warranties for this specific profile.
  • Labor intensive – The engineered details for this installation are labor-intensive because all of the panels must be screwed together at the seam.
  • Small width – For the SMI 1.0” FWP, the panel widths are on the smaller side (approximately 12” from seam to seam). Depending on where the wall system is being installed, the small width may or may not be a big deal.
  • Vertical installation – To get the engineering on this profile, you can only install the system vertically so the seams are perpendicular to the ground. If you don’t want the warranties or engineering, you can install it horizontally if desired.


Wrapping it All Up

While these profiles are just a handful of the options that we offer to our customers, we hope this gives you a better idea of the variety of choices, advantages, and disadvantages to help you make the right decision. A full listing of profiles can be found on our website.

To further assist with your decision, ask yourself the following questions:

  • Do I want/need an engineered system?
  • Do I want/need a weather-tight warranty?
  • How much do I want to spend?
  • Is my budget flexible for accessories or extra materials?
  • What is the pitch of my roofing structure?
  • Do I want/need a quick or less labor-intensive installation?
  • How long and wide do I want/need the panels to be?

Here at Sheffield Metals, we’ve dedicated ourselves to providing our customers with the materials, instructions, details, and support on all metal roofing and wall system projects. That’s why we offer a variety of tested and proven panel profiles for any application, whether it’s commercial, architectural, or residential.

To inquire about any of our panel profiles, please contact one of our experienced technical representatives today.

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Julianne Calapa

Julianne CalapaJulianne Calapa

Content Specialist

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Sheffield Metals is a leader in the distribution of coated and bare metal products, as well as engineered standing seam metal roof (SSMR) & wall systems. We specialize in providing painted Galvalume® and aluminum for the architecturally driven metal panel industry. Sheffield Metals has the ability to meet a wide array of needs with more than 50 colors continuously stocked. We can also match virtually any custom color to suit any project.


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