Aluminum Base and Cap for Polycarbonate Layout Over Purlins

High humidity & cold use 16 or 25mm.       Next See Load Support for purlin spacing    Also See Install Details



  • Outside of bldg. to center of 1st or last Base 48-1/2″. Intermediate Bases 49″ on-center.
  • Above dimensions same for Vertical Rafters & Studs.
  • U-Profile: Lower edge roof sheets, top & bottom of walls, bottom gable end walls, around doors & fans.
  • Screws for attaching Base to Frame & Cap to Base sent free when Base & Cap ordered.
  • Screws for Corner, at top & bottom of poly and in body of sheet Purchased Separately.
  • See Position & Attach for mid-sheet attachment of roof & wall sheets.

Polycarbonate Greenhouse and Sunroom Building Supplies