So I have my Renogy Solar kit and I’m working on affixing the panels with Z brackets to my roof.
The question is this: Should I use the fasteners from the kit which are self tapping screws, OR the second option that Renogy recommends for RV roofs but doesn’t provide which are Brass self expansion nuts.
Option 1, the screws will be biting into the fiberglass roof & maybe if I’m lucky I’ll hit a metal bar as structural element.
Option 2 is going to be the rubber nut that expands into the fiberglass when the machine screw is in.
My roof is a double walled fiberglass with insulation in between. There are a few steel roll bars throughout, but the placement of where they are may not be where the panels can fit.
Here is a photo of the roof cutout:
insulation / steel bars(unsure of locations)