Base Cap Screw Count Procedure

Base and Cap Screw Counting Procedure for screws used in perimeter and body of polycarbonate sheet.  Note Screws that come with Base & Cap.    Screws for U-Profile also provided. – Back To Hardware Page

Screw count for Perimeter of Roof, Walls, in Corners, Flashing, around Doors, Windows, Fans & in Body of the Sheet

#10 x 2″ wood or #12 x 1-1/2″ self-drilling metal screws with 3/4″ sealing washers
used when screwing through 8mm, 10mm & 16mm polycarbonate.
#10 x 2-1/2″ wood or #12 x 2″ self-drilling metal screws with 3/4″ sealing washers
used when screwing through 25mm polycarbonate.

Roof, High Wind Area? See Structural Load Page for Purlins & Rafters
• Use 1 screw per ft along top edge of roof slope. Set screw through ridge flashing, into purlin or blocking below.
• Use 1 screw per ft along lower edge of sheet, position between Base & Cap.
• Aluminum Corner Trim (1 screw 2″ from ends and every 12″ along each leg of Corner).

Walls, High Wind Area? See Structural Load Page for Purlins & Rafters
• Aluminum Corner Trim (1 screw 2″ from ends and every 12″ along each leg of Corner).
• On side or front walls, 1 screw per ft along top & bottom edge of sheet, position between Base & Cap. Screw goes through sheet, into girts or top & bottom plates.
• On gable ends, with Corner Trim at top of sheet, 1 screw per ft along the bottom edge of sheet, position between Base & Cap. Screw goes through sheet and into girts or bottom plates. See above for screw placement in Corner Trim.

Around Doors, Fans, Shutters 1 screw every 12″ around perimeter of these items as needed.

Screws in Body of Sheet See Polycarbonate Position & Attach

U-Profile Screw Instructions: 3/8″ Self-Drill Screws to secure lower roof U-Profile supplied free with order of U-Profile. Sufficient self drill screws provided should customer choose to use in all locations. Screws are color matched. At lower edge of slope (eave) set screws every 8″ on-center. When using these screws at other locations set them 12″ on-center.

Note: Base Screws are attached to roof purlins and wall girts as laid out in your design. If attaching to rafters position 1″ from ends and about every 12″ on-center. Cap screws are positioned 1-1-2″ from ends and about every 12″ on-center. If installation is in a hurricane zone contact Sundance Supply for recommendations.

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