This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 4. Construction Safety Orders
Article 22. Scaffolds--Various Types

Return to index
New query

§1641. Heavy-Trade Wooden Pole Scaffolds.

(a) Pole scaffolds to be used by bricklayers, stonemasons, concrete workers, or other trades using heavy tools or storing heavy material on the scaffold shall be constructed as follows:

(See Plate B-19, Appendix):

(b) When buggies are used on scaffolds to transport concrete, a strong scaffold shall be designed that is capable of supporting a concentrated load equal to the weight of a loaded buggy at any point on girders, beams, or planking.

(c) Uprights. For heights not to exceed 20 feet, the uprights shall be of 4-inch by 4-inch lumber or heavier material, with a space of 4 feet between uprights at right angle to the wall and not more than 7 feet, center to center, parallel to the wall. The splices of 4-inch by 4-inch uprights shall be made with square butt joints, and scabs of 2-inch by 4-inch material at least 48 inches long shall be nailed in place on 2 sides with 6 nails in each 1/2 of each scab. Uprights laminated from 2-inch by 4-inch material are acceptable if the joints of each lamination are staggered, and either reinforced by scabs or so arranged that they occur at or near ribbon attachment points. If the uprights rest on a surface that might cause slipping, a continuous sill or other means shall be provided to hold the uprights in place. When the scaffold is resting on earth or other such material, the uprights shall rest on and be secured to the equivalent of a 2-inch by 10-inch by 10-inch wooden base.

Note: A 1 1/8-inch by 10-inch by 10-inch piece of exterior grade plywood may be used in lieu of the wooden base mentioned above.

(d) Ledgers and Ribbons.

(1) The platform shall be supported by ledgers and ribbons, nailed or bolted to the uprights. For ledgers spanning not more than 4 feet between uprights, use either 1 piece of 2-inch by 6-inch lumber securely fastened at each point of support or 2 pieces of 1-inch by 6-inch board, 1 being on each side of the uprights and fastened securely at each point of support.

(2) Ribbons shall be 1-inch by 6-inch or heavier material securely fastened to both inside and outside uprights directly under and in contact with the ledgers. Vertical spacing of ribbons and ledgers shall not exceed 7 feet. Ribbons shall be long enough to extend from upright to upright without splices.

(e) Railing. Open sides and ends of working levels 7 1/2 feet or more above grade shall be provided with top rails and midrails as specified in subsection 1640(b)(4).

EXCEPTION: That side of bricklayers' and masons' scaffolds adjacent to the work under construction provided that the wall is higher than the adjacent work platform.

(f) Ties and Braces.

(1) The scaffold shall be rigidly tied to the building or structure by means of a double looped No. 12 iron wire, or single looped No. 10 iron wire or equivalent or stronger material used in combination with spacer blocks between inside uprights and the structure. Ties shall connect to the inside uprights, and they shall be not more than 15 feet apart vertically or horizontally.

(2) The entire scaffold shall be rigidly braced with 1-inch by 6-inch boards, and every part thereof so secured as to prevent swaying, tipping, or collapsing. The diagonal bracing shall extend in both directions across the entire outside vertical face. (See Appendix Plate B-19.)

(g) Platforms.

(1) The platform shall be not more than 4 feet wide, constructed of planks at least 2 inches thick and 10 inches wide, laid closely together. Platform planks that are butt-ended (not overlapped) must be nailed to ledgers consisting of 2-inch by 6-inch or heavier material. If the planks are not nailed, they shall be of such length that they overlap the ledgers at each end by at least 6 inches. A plank shall not overlap an unsupported end of another plank. The working platform shall cover the entire space between scaffold uprights except for the open area under the backrailing, which shall not be more than 8 inches.

(2) Platforms shall extend within 14 inches of the finished face of the building, except those used primarily by bricklayers and stonemasons shall extend to within 7 inches of the finish face of the building on which the work is being performed.

(3) When moving platforms to the next level, the old platform shall be left undisturbed until the new ledgers have been set in place ready to receive the platform planks.

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. Amendment filed 11-14-75; effective thirtieth day thereafter (Register 75, No. 46.)

2. Amendment of subsections (a), (d), and (e) filed 3-19-79; effective thirtieth day thereafter (Register 79, No. 12).

3. Amendment of subsection (c) filed 9-5-79; effective thirtieth day thereafter (Register 79, No. 36).

4. Amendment of subsection (c) filed 3-7-80; effective thirtieth day thereafter (Register 80, No. 10).

5. Amendment filed 7-24-87; operative 8-23-87 (Register 87, No. 33).

6. Editorial correction to insert subsection (a) indicator (Register 91, No. 23).

Go BackGo Back to Article 22 Table of Contents