You should fasten the panel in the lower flat pan area. These 1-1/2" screws will show through the bottom. You could spray paint the under side of the roof to make the screws less noticible.
A metal-specific circular saw blade can be used for cutting panels. Turbo-shears work well for fast cutting over the ribs and tin snips are great for detail work. Make sure to brush metal shavings off the panel and always wear eye and ear safety gear.
Assuming fastening every 2'. Fasten both ends with 8 fasteners (one on each side of the rib). Fasten field of the panel with 5 fasteners (one side of rib and lap side). 2 x 8 = 16 and 4 x 5 = 20. 36 total fasteners. If spacing is closer adjust the rows.
Number of screws and placement depend on the panels you are securing and must meet local codes, but typically 40 screws should be used per square for 2' wide panels and 80 screws should be used per square for 3' wide panels.
Spacing of supports will vary from region to region of the country because of different snow loads and wind loads to account for. Typical spacing is 24-30 inches on center for common areas.
The 1-1/2" Woodscrew is a #9.
Our wood screws that are sold with the panels is designed to attach to a wood substrate whether it be plywood or wood rafters. Attachment to other materials such as PVC supports is not recommended. Concern is the weak pullout values the PVC piping would have.
The #10 wood screw will work
yes cause they go into the wood under roofing and not draw two sheets together if using on open stringers with nothing under they will work but stitch screws are cheaper
Not available in 2in