Overlap Detail Base Cap Install System
Push 3/4″ backer rod between upper and lower sheets of poly. Use polyethylene backer rod from Best Materials and silicone, for seal. Always lay initial bead of sealant and cap with same sealant after 72 hours.
See 8 – 25mm Polycarb some are 20 Yr Warranty – Lexan Thermoclear is clearly the industry leader