Base & Cap Recommended Loading lbs./sq. ft. 48" wide Sheet - Back to Home Page
 
• Load Chart & Bending Radius - Roof Purlin & Wall Girt Framing -
( Bending Radius for both polycarbonate and Base & Cap )
-
Purlin Spacing
48"
45"
42"
36"
30"
28"
Bending Radius
8mm Poly
NA
NA
NA
20 lbs.
35 lbs.
40 lbs.
8 Feet
10mm Poly
NA
NA
20 lbs.
35 lbs.
50 lbs.
60 lbs.
8 Feet
16 & 25mm 3-wall
20 lbs.
30 lbs.
35 lbs.
60 lbs.
75 lbs.
95 lbs.
9 Feet
Purlin Spacing
90"
75"
63"
54"
48"
36"
Bending Radius
16mm X-Wall
NA
NA
20 lbs.
35 lbs.
45 lbs.
80 lbs.
10 Feet
25mm X-Wall
20 lbs.
35 lbs.
50 lbs.
60 lbs.
80 lbs.
105 lbs.
Do Not Bend
Outside of structure to center of 1st & framing member & Base is 48.5".- Structural Load on snow & wind load
On-Center of framing members & Base is 49".
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• Load Support & Blocking Placement when setting poly on vertically running member- Rafters & Studs
Outside of structure to center of 1st & framing member & Base is 48.5".- Structural Load on snow & wind load
On-Center of Intermediate framing members & Base is 49"
 
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.
16 & 25mm 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 1st & framing member & Base is 48.5".- Structural Load on snow & wind load
On-Center of Intermediate framing members & Base is 24.5"
No spacers needed on blocking, but hold back 1/4" from surface of poly. 25mm for 80 plus lb. load
 
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 3 ft.
10mm Poly
24-1/2"
every 7 ft.
every 6 ft.
every 5 ft.
every 4 ft.
16 & 25mm 3-wall
24-1/2"
not needed
every 7 ft.
every 6 ft.
every 6.5 ft.
16mm X-Wall
24-1/2"
not needed
every 9 ft.
every 8 ft.
every 9 ft.
25mm X-Wall
24-1/2"
not needed
not needed
not needed
not needed
 
Heavy wind & snow loads
Thickness
Rafter Spacing
80 lb. load
105 lb. load
16mm X-Wall
48 3/4" to 49"
every 3.5 ft.
every 2.5 ft.
16mm X-Wall
24 3/8" to 24 1/2"
not needed
not needed
25mm X-Wall
48 3/4" to 49"
every 4.25 ft.
every 4 ft.
25mm X-Wall
24 3/8" to 24 1/2"
not needed
not needed
 
Sheet must be supported on all 4 edges, minimum of 1/2" of sheet bearing on Base or frame. When using sheets cut along width, and no longer have rib at edge, position so first rib supported by minimum of 1/2". Also see Position & Attach Guidelines
Chart is poly. mfg. specs for selecting sheet thickness, rafter spacing and blocking placement to support loads on poly. Chart may be used for roof or wall design.
 
Local bldg. dept. provides snow & wind load for your area. Ability to support load factor of frame strength and poly. sheet rigidity. Follow chart above and poly. sheet will support load.. 
B
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