Mounting solar hot water panels on standing seam metal roof
I need to mount 4 solar hot water panels on a standing seam metal roof in Zone 4a. When asked about mounting hardware (S5, Unirac, etc.), solar guy says to screw directly into decking instead: has never had any problems with penetration leaks, and the hardware needs periodic tightening.
Comments?
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I have no hands-on experience with metal roofing so the following is just my opinion. It was my understanding that most standing seam panels are securely fastened at the top, with clips everywhere else that allows the panels to expand and contract as required under heating/cooling. Assuming the panel is secured at other points what happens when the panel expands? What will give first, the fasteners at the top, the fasteners at the solar water heating panel or the metal itself? Or will the metal panels "oilcan" up? And most importantly, what does the roof manufacturer and installer say? If this was a recent installation will your roof warranty be voided by such an installation? I would not consider the hardware requiring periodic checking to be a bad thing as the collectors should probably be inspected for damage on a yearly basis anyway