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
§1648. Ladder-Jack Scaffolds.

(a) Ladder-jack scaffolds shall not be used when the platform is over 16 feet above the ground. Not more than two employees shall be allowed on a scaffold of this type. The ladders shall be secured against displacement. (See Plate B-34, Appendix.)

(b) The platform shall be at least 14 inches wide consisting of ladder staging, “structural plank” or equivalent, free from damage that affects the strength. The ladders shall not be placed over 16 feet center to center, and where the platform consists of a single-dressed 2-inch by 14-inch plank, the spacing shall not be greater than 12 feet. Both metal and wood platform planks shall overlap the bearing surface by at least 12 inches.

(c) Drop lines of at least 3/4-inch diameter Manila rope or other rope of equivalent diameter and strength shall hang from secure overhead anchorages where the working platform is 7 1/2 feet high or more. An independently anchored line shall be provided for and used by each employee in accordance with the provisions of Article 24 of the Construction Safety Orders.

(d) All ladders used in connection with ladder jack scaffolds shall be Type I, IA, or IAA duty rated ladders and shall be designed and constructed in accordance with the General Industry Safety Orders, Section 3276(c). Job-built ladders shall not be used for this purpose.

NOTE: See Section 3276(d) for portable ladder types, duty ratings and working loads.

(e) The ladder jack shall be so designed and constructed that it will bear on the side rails in addition to the ladder rungs, or if bearing on rungs only, the bearing area shall be at least 10 inches on each rung.

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 subsection (b) filed 3-19-79; effective thirtieth day thereafter (Register 79, No. 12).

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

4. Amendment of subsection (d), including new explanatory Note, filed 12-8-2010; operative 1-7-2011 (Register 2010, No. 50).

Go BackGo Back to Article 22 Table of Contents