Standing Seam Clamps

From snow retention and solar panels to signage, HVAC units and even stabilizing gas piping, standing seam clamps are used to keep units in place. However, knowing which clamp to use for a specific accessory and how the clamps carry the load is critical to durable performance.

When using clamps to attach accessories to a standing seam roof, the applications are virtually endless

By Ken Webb
By Jerod Webber

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Snow Retention Clamps

The Dyna-Clamps used for snow retention have two attachment setscrews that, when properly installed and torqued, keep the clamp from migrating down the seam when under a load. Testing of clamps for snow retention should be done on a variety of panel types and manufacturers. This testing information will aid in calculating how many clamps are needed and the pattern in which the clamps need to be installed to properly handle the loads required for a specific project. When planning for roof-top attachment of accessories such as solar panels, the clamps used are a mini style, which uses only one setscrew for attaching the clamp to the standing seam.

A word of caution: this type of clamp should not be used for snow retention management systems. Mini-style clamps are used for mounting applications where the load from the accessory being mounted on the roof transfers to the structural members of the roof system. In both instances, the clamps described here will also have accessory mounting holes that will allow multiple options for attachment.

Fall Protection Standing Seam Roof Clamp

When contractors are working on a standing seam roof, a roof clamp is available for safety tie off. The standing seam roof clamp installs over a clip on a completely seamed attached roof section. The unique flip design of the DFSSRC-03 clamp allows for fit on both the Butler MR24 and Butler VSR-style seams just by removing the bolts, turning one side of the clamp around the ring and replacing the bolts. The advantage of this clamp is that there is no damage to the roof panels or finished seams, and no roof penetrations.

This durable, all-steel construction standing seam roof clamp is available with zinc electroplate finish, and have been tested to meet and exceed the following OSHA standards. 1926.502 (d) (2), (3), (4) and (15): Anchorages for attachments of personal fall arrest equipment.

Metal Roofing Fasteners

Self-drilling screws for metal roofing are designed to drill, tap and install in a one-step operation. Fasteners are available in different diameters, lengths, drill points, head styles and coatings. When selecting a standing seam clip screw for a metal roofing job it is critical to choose the proper fastener to attach clips to the substrate. If fastening into steel a self-drilling screw with a pancake head and the correct drill point is required. Fastening into wood or plywood you can use the same pancake head, but the clip screw would have a Type-17 point that acts as a wood self-driller.

The length of the drill bit on the fastener will determine the drilling capacity of the screw. For instance, a T-1 is used for sheet-to-sheet stitching with a total steel thickness of 0.024 to 0.095 inches. T-3, or purlin screw, is used for a total steel thickness of 0.036 to 0.210 inches. T-4s are used for steel to structural steel with a total steel thickness of 0.125 to 0.375 inches. T-5s are also used for steel to structural steel with the total steel thickness of 0.25 to 0.5 inches.

Ken Webb and Jerod Webber are sales managers for Dynamic Fastener, Kansas City, Mo. To learn more, visit or call (800) 821-5448.

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