S-5-U™ Clamp

The answer to this question varies with the load direction, the seam profile, the roof material and the clamp model.

These variables result with a wide range of holding capacities from ±300 lbs (235 kg) to ±4,000 lbs (1800 kg). This is why for critical applications it is important to correctly identify the roof panel, seam type, gauge, etc. along with the recommended seam clamp for the specific roof. When used on some “applied cap” architectural type seam styles, S-5! may yield low load-to-failure results as compared with integrated seam profiles. Always check our load table to verify the correct allowable holding strength on your specific roof type.

Our standard test procedures are to test the Mini (one setscrew) clamps with negative load normal to seam, and standard (two setscrew) clamps with load parallel to seam. We have performed numerous parallel to seam datum tests on Mini clamps and concluded from engineering analysis the Mini clamp is (conservatively) obtaining more than ½ the strength of the standard clamps. In fact, the majority of the datum testing indicates the strength of a Mini is closer to 2/3 the strength of a standard clamp. 

If certification of the load application parallel to seam is critical to your application, we suggest using the standard (two setscrew) design. 

The setscrews, which make a small dimple in the panel seam, optimizing holding strength, are normally tensioned to 115 inch-pounds for test purposes. This is because the tools normal to the trade are rated at this tightening torque. But there are some exceptions to this rule. On some profiles and gauges in steel, screw tension of 115 inch-pounds will not adequately dimple the panel seam. For this reason, some tests are run with higher screw tensions on profiles with increased gauge or thickness.

The appropriate setscrew tension is always published on installation instructions for every clamp. When the tested torque is 115 in. lbs. the recommended installation torque instructs a window between 130 to 150 in. lbs. to be sure the tested torque is reached. When test torque is higher, the corresponding window is also higher.

S-5! clamps will not fit on face-fastened trapezoidal rib or corrugated type panels. While our clamps won't work on thru-fastened roofs, we do have bracket products for them. Explore our entire line of brackets.

S-5! products will not fit to hollow “batten” seam type panels (see images in red below) - but can be used for the traditional (wood-backed) batten seam folded joints, as shown below in green.

Any time there is a folded seam we can usually attach a clamp to it. A great way to know if we have a product for your roof is to determine what the roof is with our "Clamp-to-Seam tool".