It's not an issue for S-5 but rather for the roofing and the supports; S-5 has no control over how much the array weighs. You may need to get help from a structural engineer.
Right, I had the same thought, that S-5! Doesn't supply the roofing, but come on this stuff is mostly all the same, and besides they supply pull out and shear which is certainly coordinated with the gauge of the roofing material.
I think your main unaddressed concern is the dead weight loading on the roof support structure, which depends on joist spacing, purlin material, etc. which S-5 (understandably, IMO) does not want to address. Somebody else's problem.
No not the roof loading, that has been approved by an engineer. I am talking about the point load of the array on the metal roofing ribs. It just seems to be a blind spot that nobody addresses.
Point loads should only be falling on structural elements below the roof deck, never between. Are you talking about continuous loads? Take a piece of Unistrut and lay it on the roof, it is a continuously loaded beam, but it is actually supported by the structure below the sheet metal.
Well for standing seam it's literally a blind spot, because you can't see the fasteners holding down the panelling. But with the Corrubracket aren't you screwing into the roof structure? If so why do you need to worry about loading in the roof metal? Also what are you then putting on top? Rail? Follow the rail manufacturers guidance?
www.s-5.com
All this doesn't make any difference from my imagined S-5 perspective. S-5 provides the coupling between the roof membrane and the racking. They test, publish, and warranty their brackets' ability to resist being pulled off the roof, which is the only thing they have control over. The dead and point loading on the roof is determined by the weight of whatever the installer puts on them; that and the structural integrity of the roof system are not within S-5's purview.Some of the clamps put the weight on the flat part of the metal roofing. If there is sheathing under, then yes that weight would be then immediately transferred to the sheathing. But if you don't have Sheathing, and don't put the brackets over purlins, then just the metal roofing will be taking the weight. But consider these, which put the weight on the rib, where there is no backing:
RibBracket™ Metal Roof Brackets | Exposed-Fastened Metal Roof Brackets | S-5!
The RibBracket is used to mount HVAC, solar PV, snow guards and more onto common North American exposed-fastened, trapezoidal-rib roof profiles.
Again, I am talking about the interface between the S-5 and the roofing, and how much weight the rib it is attaching to can take before yielding. Seems like a very fundamental thing to test and provide a number for. Like I said, they do provide pull out and sheer which involve the yield strength of the roofing material so I don't buy that argument that they don't have control or it's out of their purview to provide acceptable load normal to the plane of the roof.
Are you talking about how much weight you can put on an S-5 clamp before the clamp itself collapses? I'm pretty sure that would be such a high value as to be pretty much meaningless in a normal analysis. S-5 does not warranty anything but the clamps themselves and their ability to resist being pulled off the roof. The integrity of the roof system itself is not their problem, nor should it be. You are tilting at a windmill here; their policy is not likely to change.
In addition to depending on roof material and thickness, this is going to depend on the rib and sheet geometry, as well as the locations where the panel is fastened to the roof framing. In other words, this is a global question.
Yes, but this is a local question which just depends on the roof material and thickness. I don't have access to the testing reports, but I expect the tests are done with a fairly small sample of roof material that is clamped on its perimeter.
As far as I can see you are in a minority of one. Have you looked at any of the S-5 pullout tables? Yes, of course, they consider the roofing material and show different numbers. What you are suggesting, however, is that S-5's warranty should cover factors over which they have no control. Get a structural engineer; that's what they do.
