| Maximum intended nominal load (lb/ft2) | Maximum permissible span using full thickness undressed lumber (ft) | Maximum permissible span using nominal thickness lumber (ft) |
| 25 | 10 | 8 |
| 50 | 8 | 6 |
| 75 | 6 |
| Rated load capacity | Intended load |
| Light-duty | *25 pounds per square foot applied uniformly over the entire span area. |
| Medium-duty | *50 pounds per square foot applied uniformly over the entire span area. |
| Heavy-duty | *75 pounds per square foot applied uniformly over the entire span area. |
| One-person | *250 pounds placed at the center of the span (total 250 pounds). |
| Two-person | *250 pounds placed 18 inches to the left and right of the center of the span (total 500 pounds). |
| Three-person | *250 pounds placed at the center of the span and 250 pounds placed 18 inches to the left and right of the center of the span (total 750 pounds). |
| Single Pole Wood Pole Scaffolds | ||||
| Light duty up to 20 feet high | Light duty up to 60 feet high | Medium duty up to 60 feet high | Heavy duty up to 60 feet high | |
| Maximum intended load (lbs/ft2) | 25 | 25 | 50 | 75 |
| Poles or uprights | 2 x 4 in. | 4 x 4 in. | 4 x 4 in. | 4 x 6 in. |
| Maximum pole spacing (longitudinal) | 6 feet | 10 feet | 8 feet | 6 feet |
| Maximum pole spacing (transverse) | 5 feet | 5 feet | 5 feet | 5 feet |
| Runners | 1 x 4 in. | 1 1/4 x 9 in. | 2 x 10 in. | 2 x 10 in. |
| Bearers and maximum spacing of bearers: 3 feet | 2 x 4 in. | 2 x 4 in. | 2 x 10 in. or 3 x 4 in. |
2 x 10
in. or 3 x 5 in. |
| 5 feet | 2 x 6 in. or 3 x 4 in. |
2 x 6 in. or 3 x 4 in. (rough) |
2 x 10 in. or 3 x 4 in. |
2 x 10
in. or 3 x 5 in. |
| 6 feet | --- | --- | 2 x 10 in. or 3 x 4 in. |
2 x 10
in. or 3 x 5 in. |
| 8 feet | --- | --- | 2 x 10 in. or 3 x 4 in. |
|
| Planking | 1 1/4 x 9 in. | 2 x 10 in. | 2 x 10 in. | 2 x 10 in. |
| Maximum vertical spacing of horizontal members | 7 feet | 9 feet | 7 feet | 6 ft. 6 in. |
| Bracing horizontal |
1 x 4 in. | 1 x 4 in. | 1 x 6 in. or 1 1/4 x 4 in. |
2 x 4 in. |
| Bracing diagonal | 1 x 4 in. | 1 x 4 in. | 1 x 4 in. | 2 x 4 in. |
| Tie-ins | 1 x 4 in. | 1 x 4 in. | 1 x 4 in. | 1 x 4 in. |
| Independent Wood Pole Scaffolds | ||||
| Light duty up to 20 feet high | Light duty up to 60 feet high | Medium duty up to 60 feet high | Heavy duty up to 60 feet high | |
| Maximum intended load | 25 lbs/ft2 | 25 lbs/ft2 | 50 lbs/ft2 | 75 lbs/ft2 |
| Poles or uprights | 2 x 4 in. | 4 x 4 in. | 4 x 4 in. | 4 x 4 in. |
| Maximum pole spacing (longitudinal) | 6 feet | 10 feet | 8 feet | 6 feet |
| Maximum (transverse) | 6 feet | 10 feet | 8 feet | 8 feet |
| Runners | 1 1/4 x 4 in. | 1 1/4 x 9 in. | 2 x 10 in. | 2 x 10 in. |
| Bearers and maximum spacing of bearers: 3 feet | 2 x 4 in. | 2 x 4 in. | 2 x 10
in. (rough) |
2 x 10 in. |
| 6 feet | 2 x 6 in. or 3 x 4 in. |
2 x 10 in. (rough) or 3 x 8 in. |
2 x 10 in. | 2 x 10
in. (rough) |
| 8 feet | 2 x 6 in. or 3 x 4 in. |
2 x 10 in. (rough) or 3 x 8 in. |
2 x 10 in. | |
| 10 feet | 3 x 4 in. | 2 x 6 in. (rough) or 3 x 3 in. |
2 x 10 in. | |
| Planking | 1 1/4 x 9 in. | 2 x 10 in. | 2 x 10 in. | 2 x 10 in. |
| Maximum vertical spacing of horizontal members | 7 feet | 7 feet | 6 feet | 6 feet |
| Bracing horizontal |
1 x 4 in. | 1 x 4 in. | 1 x 6 in. or 1 1/4 x 4 in. |
2 x 4 in. |
| Bracing diagonal | 1 x 4 in. | 1 x 4 in. | 1 x 4 in. | 2 x 4 in. |
| Tie-ins | 1 x 4 in. | 1 x 4 in. | 1 x 4 in. | 1 x 4 in. |
| Minimum Size of Members | |||
| Light duty | Medium duty | Heavy duty | |
| Maximum intended load | 25 lbs/ft2 | 50 lbs/ft2 | 75 lbs/ft2 |
| Posts, runners and braces | Nominal 2 in. (1.90 inches) OD steel tube or pipe. | Nominal 2 in. (1.90 inches) OD steel tube or pipe. | Nominal 2 in. (1.90 inches) OD steel tube or pipe. |
| Bearers | Nominal 2 in. (1.90 inches) OD steel tube or pipe and a maximum post spacing of 4 ft. x 10 ft. | Nominal 2 in. (1.90 inches) OD steel tube or pipe and a maximum post spacing of 4 ft. x 7 ft. or Nominal 2 1/2 in. (2.375 in.) OD steel tube or pipe and a maximum post spacing of 6 ft. x 8 ft. (*). | Nominal 2 1/2 in. (2.375 in.) OD steel tube or pipe and a maximum post spacing of 6 ft. x 6 ft. |
| Maximum runner spacing vertically | 6 ft. 6 in. | 6 ft. 6 in. | 6 ft. 6 in. |
| Light duty | Medium duty | Heavy duty | Maximum height of scaffold (in feet) | |
| Duty Number of Working Levels: | ||||
| 1 | 16 | 11 | 6 | 125 |
| 2 | 11 | 1 | 0 | 125 |
| 3 | 6 | 0 | 0 | 125 |
| 4 | 1 | 0 | 0 | 125 |
| Length of Platform | 12 feet | 14 & 16 feet | 18 & 20 feet |
| Side stringers, minimum cross section (finished sizes): | |||
| At ends | 1 3/4 x 2 3/4 in. | 1 3/4 x 2 3/4 in. | 1 3/4 x 3 in. |
| At middle | 1 3/4 x 3 3/4 in. | 1 3/4 x 3 3/4 in. | 1 3/4 x 4 |
| Reinforcing strip (minimum) | A 1/8 x 7/8 inch steel reinforcing strip must be attached to the side or underside, full length. | ||
| Rungs | Rungs must be 1 1/8 inch minimum diameter with at least 7/8 inch in diameter tenons, and the maximum spacing must be 12 inches to center. | ||
| Tie rods: Number (minimum) |
3 | 4 | 4 |
| Diameter (minimum) | 1/4 inch | 1/4 inch | 1/4 inch |
| Flooring, minimum finished size | 1/2 x 2 3/4 in. | 1/2 x 2 3/4 in. | 1/2 x 2 3/4 in. |
| Length of Platform | 22 & 24 ft. | 28 & 30 ft. | |
| Side stringers, minimum cross section (finished sizes): | |||
| At ends | 1 3/4 x 3 in. | 1 3/4 x 3 1/2 in. | |
| At middle | 1 3/4 x 4 1/4 in. | 1 3/4 x 5 in. | |
| Reinforcing strip (minimum) | A 1/8 x 7/8 inch steel reinforcing strip must be attached to the side or underside, full length. | ||
| Rungs | Rungs must be 1 1/8 inch minimum diameter with at least 7/8 inch in diameter with at least 7/8 inch in diameter tenons, and the maximum spacing must be 12 inches to center. | ||
| Tie rods: Number (minimum) |
5 | 6 | |
| Diameter (minimum) | 1/4 in. | 1/4 in. | |
| Flooring, minimum finished size | 1/2 x 2 3/4 in. | 1/2 x 2 3/4 in. | |
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