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Subchapter 7. General Industry Safety Orders
Group 4. General Mobile Equipment and Auxiliaries
Article 23. Mobile Ladder Stands and Scaffolds (Towers)
(a) “All scaffolds shall be erected in accordance with the provisions of Article 21 of the Construction Safety Orders.”
(b) Load Rating.
(1) The design working load of ladder stands shall be calculated on the basis of one or more 200-pound persons together with 50 pounds of equipment each.
(2) The design load of all scaffolds shall be calculated on the basis of:
(A) Light -Designed and constructed to carry a working load of 25 pounds per square foot.
(B) Medium -Designed and constructed to carry a working load of 50 pounds per square foot.
(C) Heavy -Designed and constructed to carry a working load of 75 pounds per square foot.
(3) All ladder stands and scaffolds shall be capable of supporting at least 4 times the design working load.
(c) Materials. The materials used in mobile ladder stands and scaffolds shall be selected to safely support the design working load and shall be maintained to protect against corrosion and deterioration.
(d) Fasteners. Nails, bolts, or other fasteners used in the construction of ladders, scaffolds, and towers shall be of adequate size and in sufficient numbers at each connection to develop the designed strength of the unit. Nails shall be driven full length. (All nails shall be immediately withdrawn from dismantled lumber.)
(e) Workmanship. All exposed surfaces shall be free from sharp edges, burrs, or other laceration hazards.
(f) Work Levels.
(1) The maximum work level height shall not exceed 3 times the least base dimension below the platform. Where the basic mobile unit does not meet this requirement, outrigger frames shall be employed to achieve this least base dimension, or provisions shall be made to guy or brace the unit against tipping.
(2) The minimum platform width for any work level shall not be less than 20 inches for mobile scaffolds (towers). Ladder stands shall have a minimum step width of 16 inches.
(3) The supporting structure for the work level shall be rigidly braced, using cross bracing or diagonal bracing with rigid platforms at each work level.
(4) The steps of ladder stands shall be slip-resistant.
(5) The work level platform of scaffolds (towers) shall be the full width of the scaffold, except for necessary openings. Work platforms shall be secured in place. All scaffold platforms shall meet the requirements of the Construction Safety Orders, Section 1637.
(6) All scaffold work levels 6 feet or higher above the ground or floor shall have a toeboard at locations where persons are required to work or pass under the scaffold. (See Section 3210.)
(7) All scaffold work levels 30 inches or higher above the ground or floor shall have guardrail protection that meets the requirements of Section 3209 and 3210.
(8) A climbing ladder or stairway shall be provided for proper access and egress, and shall be affixed or built into the scaffold and so located that its use will not have a tendency to tip the scaffold. A landing platform shall be provided at intervals not to exceed 30 feet.
(g) Wheels or Casters.
(1) Wheels or casters shall be properly designed for strength and dimensions to support 4 times the design working load.
(2) All scaffold wheels, casters and swivels shall be provided with a positive locking device, or other effective means to prevent movement of the scaffold.
(3) Ladder stands shall have at least 2 locking casters or other means of locking the unit in position. If only 2 casters are used, they shall be of the directional type and if 4 casters are used, at least 2 of the 4 shall be of the swivel type.
(4) Locking devices shall be kept in the locked position when workers are climbing or working on scaffolds and ladder stands.
(5) Where leveling of the elevated work platform is required, screw jacks or other similar means for adjusting the height shall be provided in the base section of each mobile unit. The screw jack shall extend into its leg tube at least 1/3 its length, but in no case shall the exposed portion of the screw jack exceed 12 inches.
1. Amendment of subsection (a) filed 11-18-76; effective thirtieth day thereafter (Register 76, No. 47).
2. Amendment of subsections (a)(3), (e)(1), (e)(6) and (f) filed 12-19-78; effective thirtieth day thereafter (Register 79, No. 1).
3. Amendment filed 10-12-84; effective thirtieth day thereafter (Register 84, No. 41).
4. Amendment of subsection (f)(5) filed 6-19-2001; operative 7-19-2001 (Register 2001, No. 25).
5. Amendment of subsection (f)(5) filed 11-2-2010; operative 12-2-2010 (Register 2010, No. 45).
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