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

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§1645. Outrigger and Bracket Scaffolds.

(a) Heavy Trades.

(1) Outrigger beams of outrigger scaffolds for use by bricklayers, stonemasons, or other heavy trades shall be made of "selected lumber," or better. Those of the following sizes shall not project more than 6 feet beyond the outer support; shall be securely anchored and braced to prevent tipping or turning; and shall be spaced at centers of 7 feet 6 inches, or closer.

The inboard end of outrigger beams, measured from the fulcrum point to anchorage point, shall not be less than 1 1/2 times the outboard end in length. The fulcrum point of the beam shall rest on a secure bearing at least 6 inches square.

(2) On continuous scaffolds, where the beams may receive load from work platforms on each side, such beams shall not be less than 3 inches by 16 inches in cross section. For single scaffolds, consisting of a platform between 2 beams, the outrigger beams may have a smaller cross section, but not less than 3 inches by 12 inches. The platforms shall consist of planks, at least 2 inches by 10 inches, covering the full width of the projection. Planking shall be nailed or bolted or otherwise secured to outriggers.

The ends of the planks shall not project more than 18 inches beyond the outrigger, and not less than 6 inches, unless they are nailed in place. Every outrigger scaffold 7 1/2 feet or more in height shall be provided with a railing and toeboard. The top rail shall consist of double 2-inch by 4-inch members. One member shall be fastened in a flat position on top of the posts and the other member shall be fastened in an edge-up position to the inside of the posts and at the side of the top rail.

Additional protection in the form of screen enclosing the opening between rail and toeboard shall be provided if material on the scaffold is piled higher than the toeboard.

(3) Where additional working levels are required to be supported by the outrigger method, the plans and specifications of the outrigger and scaffolding structure shall be prepared by a Civil Engineer currently registered in California.

(b) Figure Four or Light Outrigger Scaffolds. (See Plate B-22, Appendix.) Figure Four or light outrigger frames shall be spaced not more than 10 feet apart, and shall be constructed as follows from sound lumber:

The outrigger ledger shall consist of 2 pieces of 1-inch by 6-inch or heavier material nailed on opposite sides of the vertical and angle braces. Ledgers shall project not more than 3 feet 6 inches from the outside wall line and shall be substantially braced and secured to prevent tipping or turning. The knee or angle brace shall intersect the beam at least 3 feet from the wall at an angle of 45 degrees, and the lower end shall be nailed to a vertical brace near the point where it contacts the wall. The platform shall consist of 2 or more 2-inch by 10-inch planks, which shall be of such length that they extend at least 6 inches beyond ledgers at each end. Unsupported projecting ends of planks shall be limited to an overhang of 18 inches, or less.

Each wooden bracket shall be hooked over a well-secured and adequately strong supporting member.

Every Figure Four or light outrigger scaffold 7 1/2 feet or more in height shall be provided with a railing and toeboard. The top rail shall consist of double 2-inch by 4-inch members. One member shall be fastened in a flat position on top of the posts and the other member shall be fastened in an edge-up position to the inside of the posts and at the side of the top member.

(c) Stud Jacks. (See Plate B-40, Appendix.) Stud-jack scaffold supports shall have ledgers of at least 2-inch by 6-inch materials, or equal, not longer than 5 feet, and each jack shall attach to not less than 2 sound, adequately fastened, 2-inch by 4-inch wall studs of normal length. Stud-jack scaffolds shall not be used at elevations of 7 1/2 feet or higher above the ground, unless so designed that a substantial backrail may be easily attached.

(d) Bracket Scaffolds. The use of bracket scaffolds shall be permitted only when through-bolted to walls, with at least 5/8-inch diameter bolts; welded to steel tanks; secured with a metal stud attachment device; or, hooked over a well-secured and adequately strong supporting member.

NOTE: This Order does not prohibit the use of bracket scaffolds that are an integral part of movable form panels or similar construction. (See Plates B-20 and B-21, Appendix.)

All form scaffolds shall be designed and erected with a minimum safety factor of 4, computed on the basis of the maximum rated load; i.e., the total of all loads including the working load, the weight of the scaffold, and such other loads as may be reasonably anticipated.

(1) Spacing of brackets shall be such that they are not more than 10 feet apart horizontally.

(2) If brackets are secured to walers held by snap-tie or she-bolts, they must extend through both wall forms and be properly secured.

(3) Railings shall be installed on bracket scaffolds for all heights 7 1/2 feet or more above the ground.

(4) The platform shall consist of two or more 2-inch by 10-inch planks, laid closely together, and shall be of such length that they overlap the ledgers at each end by at least 6 inches. Unsupported projecting ends of planks shall be limited to an overhang of 18 inches or less.

(5) Wooden bracket form scaffolds shall be an integral part of the form panel and shall not be used to support loads exceeding 25 pounds per square foot, unless specifically designed for a heavier loading. Ledgers shall be made from 2-inch by 6-inch or heavier material and shall not project more than 3 feet 6 inches from the form panel. Uprights shall consist of 2-inch by 4-inch or heavier material. Scaffold planks shall be either nailed, wired or bolted to the ledgers. Planks shall overlap the ledgers at each end by at least 6 inches. Unsupported projecting ends of platform planks shall be limited to a maximum overhang of 18 inches. Ledgers shall not be spaced more than 8 feet on centers. (See Appendix Plate B-20.)

(6) Bracket scaffolds installed on metal tanks larger than 40 feet in diameter for the use of those engaged in tank erection operations, shall have platforms that are at least 30 inches wide, with the open ends and sides protected by a substantial railing, with midrail, which may be altered by the substitution of 3/8-inch wire rope for the top and middle rails. Platforms on 40-foot or smaller diameter tanks will be acceptable if not less than 24 inches in width, consisting normally of two 2-inch by 12-inch planks side by side, protected by railings as described above.

NOTE: For railing requirements, see Section 1620.

(e) Carpenters' Bracket Scaffolds.

(1) The brackets shall consist of a triangular wood frame not less than 2 x 3 inches in cross section, or of metal of equivalent strength. Each member shall be properly fitted and securely joined.

(2) Each bracket shall be attached to the structure by means of one of the following:

(A) A bolt, no less than 5/8-inch in diameter, which shall extend through to the inside of the building wall;

(B) A metal stud attachment device;

(C) Welding to steel tanks;

(D) Hooking over a well-secured and adequately strong supporting member.

(3) The brackets shall be spaced no more than 10 feet apart.

(4) No more than two employees shall occupy any given 10 feet of a bracket scaffold at any one time. Tools and materials shall not exceed 75 pounds in addition to the occupancy.

(5) The platform shall consist of not less than two 2- x 10-inch nominal size planks extending not more than 18 inches or less than 6 inches beyond each end support.

NOTE: For railings see Section 1620.

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

HISTORY

1. Editorial correction in subsection (b) (Register 70, No. 48).

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

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

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