STANDING SEAM METAL ROOFING

Selecting a quality metal roofing product for your project.

Navigational Note

If you know which metal roofing product best fits your application, you can select a metal roof product from our product selection menu on the left side at any time. For standing seam recommendations (does not include curved or tapered panels) from us, please use the quick find option on the left menu.

Metal Roofing - Types

Metal roofing is commonly used on consistent roof slopes of ¼:12or greater. There are several forms and styles.

There are three forms of metal roof:

1. Standing seam - Panels with raised seam engagements that are typically engaged and held down to the roof deck using hidden clips and fasteners.
2. Exposed fastener lap seam metal roof panels – Metal roofing panels are lapped over each other and the panels are held down using fasteners that penetrate through the panel into the structure below
3. Metal Tile/Shingles – These are supplied in a variety of appearances to simulate asphalt shingles or concrete/clay tile. Some systems use clips with concealed fasteners. Others rely on fasteners penetrating through the shingle.

Standing Seam - Panels -Styles

Standing seam panels have proven to be extremely successful when they are installed properly. There are three unique styles of standing seam panels:

1. Mechanical seam or crimp – This style of metal roof, also referred to as structural standing seam, requires the two roof panels to be engaged with a mechanical seaming tool (examples below). A double lock standing seam panel offers superior wind uplift resistance. Some forms of these panels can now be curved.  Since the two standing seam panels must be seamed together, the clip is incorporated into the panel seam.  As a result, a separate moving base or top must be used to allow the metal to thermally move.  It is critical that the bases are installed precisely to avoid conflicts that restrict thermal movement. 
   
   
2. Two-piece symmetrical mechanical seam – This style of structural standing seam is the newest, most innovative option available today.  It combines the weathertight benefits of the mechanical seam or crimp with the replacement and bi-directional installation options of a two-piece snap-lock panel (generically referred to as a tee-panel).  Unlike mechanically seamed panels, two-piece symmetrical standing seam panels, like ABC’s 238T, can be installed using fixed clips while still allowing for thermal movement.  Combining the advantages and eliminating the disadvantages involved with the various standing seam options, the two-piece mechanical seam panel is the best option for almost any roof design.  It can be curved both convex and concave.  In addition, this panel is easily tapered due to it’s symmetrical design.  Lastly, this style of metal roofing has demonstrated an ability to withstand uplift pressures well in excess of the one-piece structural standing seam panel.
   
   
   
   
3. One Piece Snap-Lock – This style of metal roof requires two panel seams to snap together. The direct attachment of the roof panels simulates the look of a mechanical seam panel without the additional operation of seaming. These metal roofing panels, despite their various structural capabilities, are best suited for decked applications with slopes of 3:12 and greater.  Snap-lock standing seam is less likely to be used in high wind uplift areas.  This is due to the fact that more clips and attachment points are required to satisfy uplift pressures.  In many instances, corner pressures (the most demanding) cannot be satisfied.  This has frequently proven to be the location where roof failure occurs in windstorms. 
   
   
4. Two Piece Snap-Lock – This style of metal roof, generically referred to as a “T” panel, requires both a panel and a cap or batten. The cap or batten unite two panels by snapping down onto a butterfly clip (example below).These metal roof panels offer very little structurally and should always be used on a solid deck with a premium underlayment. Two Piece Snap-Lock standing seam panels are easier to install on roofs with valleys and hips, due to their ability to be installed bi-directionally. Due to the simplicity of the panel shape, these metal panels lend themselves to curved and tapered roof designs.  As the capabilities of structural standing seam increase, the demand for this style of metal roofing has deteriorated.
   
   

What makes a good standing seam panel?

A good standing seam panel is one that is capable of satisfying the design of the project, including retrofit metal roofing projects. Consult a metal roofing manufacturer, like Architectural Building Components, about the capabilities of the metal roof panel prior to specifying it. Once the proper metal roofing product has been selected, it is time to discuss installation. Keep in mind that a poorly installed metal roof system will leak until it blows off.

Metal, like a lot of other materials, is vulnerable to thermal expansion and contraction. This must be a central thought of detailing a standing seam metal roof system. When performing a metal roof installation, the installer typically utilizes metal roof clips that allow for thermal movement. The associated metal roof flashing details must integrate with the thermal movement of the standing seam. The entire success of standing seam metal roofing to handle thermal movement can be negated by a single fastener going through a single panel. Consult ABC about providing shop drawings or details for your next project with standing seam.

Quality assurance measures for standing seam metal roofing:

1. Provide continuous Length Panels (No laps)
2. Avoid unnecessary end laps in trim
3. Where fasteners penetrate through the panel, provide tape or caulk sealant  
4. When fasteners must be exposed, require stainless, matching color fasteners with washers

Architectural Building Components standing seam metal roof panels are supported by UL and ASTM uplift testing, UL hail impact ratings, and UL fire ratings.