Skip to Main Content

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 23. Suspended Scaffolds
Return to index
New query

§1664. Needle-Beam Scaffold.

(a) Needle-beam scaffolds shall be designed with a factor of safety of at least 4, to support the loads to be imposed, but in no case shall the strength or quality be less than required by the following specifications. (See B-37, Appendix)

(1) Wood needle beams shall be not less than 4 inches by 6 inches in cross section, if the distance between supports does not exceed 10 feet. Larger beams are required for spans in excess of 10 feet, and in all cases they shall be placed with the greater dimension vertical. They shall be "selected lumber," or equivalent, straight-grained, and free of knots or other defects. Other materials or types may be used if of equivalent strength and rigidity.

(2) Wood needle beams shall be made from one piece of material without splices or laminated joints. Laminated wood beams, manufactured of good quality, glued members, subjected to proper bonding pressure, may along with other materials be used if of equivalent strength.

(3) Wood needle beams shall not be painted in such a manner as to hide the grain structure. They may be coated with linseed oil or other transparent coating.

(4) Ropes used for the support of needle beams shall be not less than 1 1/4-inch diameter Manila rope, or equivalent, free from flaws, deterioration, chemical damage, or other imperfections. C-clamps or open hooks shall not be used for support of needle beams or needle-beam ropes.

(5) The ropes shall be attached to the needle beams by a scaffold hitch, or some other equally effective method, at a point not less than 1 foot from the end of the beam. Ropes shall be so secured to the beams or girders as to prevent tipping or slipping of either the beam or the scaffold. When the rope attachment is within 2 feet of beam end, bolt or cleat shall be attached or other means taken to prevent rope from coming off beam.

(6) Planks making up platforms on needle beams shall not be less than 2 inches by 10 inches and not have more than a 10 foot span. All planks shall be secured by suitable cleats or drop bolts to prevent slipping, tipping, or collapsing, with special attention for those planks that are on the beam overhang outside the rope attachment. When planks are in an inclined position of 5 percent or more, they shall be provided with cleats on the working surface at least 1 3/4 inches by 2 inches in cross section, spaced not more than 16 inches apart.

(7) Platforms used for riveting or other work requiring similar tools shall be not less than 36 inches wide when used on exterior of structures, and not less than 30 inches wide for interior work.

(8) Needle-beam platforms that are used for rivet heaters shall be not less than 6 feet wide and 10 feet long, with planks laid close together, and some provision shall be made to prevent materials or tools from rolling off edges.

(9) Where the supports for needle beams are fixed members rather than suspension ropes, positive means shall be taken to prevent the beams from turning or rotating to a position where the strength is reduced.

(10) All unattached tools, bolts, and nuts used on needle beam scaffolds shall be kept in suitable containers, properly secured.

(11) If one end of a needle beam scaffold platform rests on a permanent structural section, all applicable sections of this Article and Article 23 shall be observed.

(12) Each employee working on a needle beam scaffold shall be provided with and use personal fall protection in accordance with the requirements of Article 24 or by a safety net rigged as provided in Section 1671.

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


1. Renumbering and amendment of former Section 1650 to Section 1664 filed 7-24-87; operative 8-23-87 (Register 87, No. 33).

2. Amendment of subsection (a)(12) filed 7-2-98; effective 8-1-98 (Register 98, No. 27).

Go BackGo Back to Article 23 Table of Contents