• 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 |
| 16mm 3-wall | 20 lbs. | 30 lbs. | 35 lbs. | 60 lbs. | 75 lbs. | 90 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 48.5″.- Structural Load on snow & wind load
On-Center of framing members & Base is 49″.
• Load Support & Blocking Placement when setting poly on vertically running Rafters & Studs
Outside of structure to center of 1st & framing member 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. |
| 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 1st & framing member 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 6.5 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 |
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 | every 4.5 ft. |
| 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.