Double Slope Rafter Detail, also known as gambrel roof, is typically a symmetrical two-sided roof with two slopes on each side. See detail below for simple, effective, way to install polycarbonate on these roofs. U-Profile Install Tips
Screws with Base & Cap Screw counting screws used in body of sheet and perimeter.
See 8 – 25mm Polycarb some are 20 Year – Lexan Thermoclear is clearly the industry leader