Rafter Load Support Chart – For Polycarbonate

Rafter Load Support Chart for Blocking Placement
Next See Base & Cap Install Details and do material list take off

Snow & Wind Load          Position & Attach for mid-sheet attachment.      Back To Base & Cap Pricing Page

Rafter Load Support Chart:    On-Center of framing & Base is 49″     16 & 25mm X-Wall Chart for 80 plus lb. loads

Sheet Thickness
Rafter Spacing
20 lb. load
35 lb. load
45 lb. load
60 lb. load
8mm
49″
every 3 ft.
every 2.5 ft.
every 2.25 ft.
every 2 ft.
10mm
49″
every 3.5 ft.
every 3 ft.
every 2.75 ft.
every 2.25 ft.
16mm 3-wall
49″
every 4 ft.
every 3.5 ft.
every 3.25 ft.
every 3 ft.
16mm X-wall
49″
every 5.5 ft.
every 5 ft.
every 4.5 ft.
every 3.75 ft.
25mm X-wall
49″
every 7.5 ft.
every 6.25 ft.
every 5.25 ft.
every 4.5 ft.

Outside of structure to center of first or last Base is 48-1/2″.       See Blocking Detail

On-Center of Intermediate framing members is 24-1/2″.
24.5″ on-center – No spacers, hold blocking back 1/4″ from surface of poly.  X-Wall Chart for 80 plus lb. load.

Sheet Thickness
Rafter Spacing
20 lb. load
35 lb. load
45 lb. load
60 lb. load
8mm
24-1/2″
every 6 ft.
every 5 ft.
every 4 ft.
every 3ft.
10mm
24-1/2″
every 7 ft.
every 6 ft.
every 5 ft.
every 4 ft.
16mm 3-wall
24-1/2″
not needed
every 7 ft.
every 6.5 ft.
every 6 ft.
16mm X-wall
24-1/2″
not needed
every 9 ft.
every 8 ft.
every 7 ft.
25mm X-wall
24-1/2″
not needed
not needed
not needed
not needed

Load in lbs./sq. ft. On roof slope over 7/12 snow slides off. Spacing less. No specs available.

• Sheet must be supported on all 4 edges, minimum1/2″ of sheet bearing on Base or frame. If using sheets cut along width, and no longer have a rib at edge, position so first rib supported by a minimum of 1/2″.

See 8-25mm Polycarb, some 20 yr Warranty

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