Standing seam projects require an understanding of how panels lock together. Snap-Lock panels are a more simplified means of standing seam and this post will focus on mechanically locked panels. We will take a closer look at a few ways to achieve a double lock standing seam and the tools required to do so.

Mechanically Locked Standing Seams Types

  • Field Formed Seams: The traditional method of locking metal panels together that has been used for centuries.  This method requires only a few tools and some man hours to complete a watertight roofing system. The user is able to create single or double lock seams with this folding technique. Note that the clips are concealed and locked into the panels underneath the seams leaving no roof penetrations.

The seaming process requires two flanges of metal to be bent on the panel lengths and then butt up against one another. Using a sheet metal hammer and seaming anvil, you can lock pans together. This technique is labor intensive but useful and often necessary on radius pieces.  Click the picture below for step by step instructions using a seaming anvil and a PVC hammer.

Preformed Mechanical Locking Seams

Preforming seams refers to the process of putting a male and a female leg on the panel lengths prior to installation.  This can be done in a couple ways:

  • Brake Forming – Using a brake to produce panels has its limitations due to the size of the brake and the speed of the bends. Using a 10′ brake to produce profiles is certainly possible, however alternative methods are preferred.  See illustration for instructions on forming mechanical locked panels using a manual siding brake. The picture to the right which provides exact steps for brake forming, is provided by ESE Machines. There are also computerized brakes that can create multiple bends on panels that can serve this need.
  • Roll Forming (Portable Roll Forming) – Using a roll former to produce the male and female leg of a standing seam profile. A major advantage to using a panel from a pan-former is the consistency of the profile and the speed at which it is produced. Often, portable roll forming machines can be taken directly on a job site to produce the custom length panels needed. With proper planning, the job site waste can be significantly reduced.

Once you have a male and a female profile, you can either lock the panels by hand or with a power seamer. Using a hand seamer makes sense for small sections of the roof and areas where a power seamer is too cumbersome to carry around. Power seamers are mainly used for larger commercial works when there are many of panels to seam. Larger residential projects will also benefit from the speed.