Working with scaffolding requires employees to be attentive to their actions and the task at hand. To work safely, there are numerous safety rules and regulations employees should follow. The following rules are generally accepted practices. When reviewing with employees, add any rules specific to your operations as well as any common sense rules learned through your experiences.
Scaffolding footings or anchorage must be sound and capable of carrying the maximum load without settling. Do not use unstable objects like barrels, boxes, loose bricks, or concrete blocks to support scaffolds or planks. Do not erect, move, alter, or dismantle scaffolding except under the supervision of an OSHA-defined competent person.
Guardrails made of lumber must not be less than 2-by-4 inches (or other material providing equivalent protection). They must also be between 38 inches and 45 inches high, with a midrail of 1-by-6 inch lumber (or other material providing equivalent protection), and have a minimum 3 1/2-inch high toe board on all open sides and ends on scaffolds more than 10 feet above the ground or floor. Supports must be at intervals that do not exceed 8 feet. Ramps and walkways 6 feet above lower levels must have guardrail systems. Where persons are exposed to falling objects and are required to work or pass under the scaffold, there should be a screen between the platform and the guardrail. The guardrail must extend along the entire scaffold, and support a downward or horizontal force of a minimum 200 pounds. The screen’s openings should be small enough to prevent passage of potential falling objects.
All planking of platforms must be overlapped (minimum of 12 inches) only over supports, or be secured from movement. Scaffold planks must extend over their end supports not less than 6 inches or more than 12 inches unless secured or blocked by a guardrail. Planks must be laid with their edges close together so the platform will be tight and have no spaces greater than 1 inch. Platforms more than 14 inches from the work surface must have a guardrail system and/or employees must use personal fall arrest system (for plastering and lathing = 18 inches). Work areas must be fully-planked from the front uprights to the guardrail supports. All planking must conform to the minimum requirements of Appendix A of 29CFR1926.454.
The maximum permissible spans for 2-by-10-inch planks are as follows:
10 feet - (undressed lumber) - 25 p.s.f. working load
8 feet - (undressed lumber) - 50 p.s.f. working load
8 feet - (nominal lumber) - 25 p.s.f. working load
6 feet - (undressed lumber) - 75 p.s.f. working load
6 feet - (nominal lumber) - 50 p.s.f. working load
An access ladder or equivalent safe access must be provided. Portable, hook-on, and attachable ladders should have rungs with a minimum width of 11 1/2 inches and maximum spacing between rungs of 16 3/4 inches, and have uniformly spaced rungs. Cross braces are not acceptable for scaffold access. Hook-on/attachable ladders shall be positioned so that its bottom rung is not more than 24 inches above the scaffold supporting level.
Support and Stability
Scaffolds and their components must be capable of supporting, without failure, at least four times the maximum intended load. Wire, synthetic, or fiber rope used for scaffold suspension must be capable of supporting at least six times the rated load. The poles, legs, or uprights of scaffolds must be plumb and securely braced to prevent swaying and displacement. Scaffolds must be tied back vertically at a height beginning at four times the scaffold width and then at a maximum every 26 feet (scaffolds 3 feet and wider). The horizontal distance of the ties is not to exceed 30 feet.
Each employee on a scaffold more than 10 feet above a lower level shall be protected from falling. Employees must not work on scaffolds during storms or high winds. Slippery conditions on scaffolds must be eliminated as soon as possible after they occur. Any scaffold, including accessories such as braces, brackets, trusses, screw legs, ladders, etc., damaged or weakened from any cause must be immediately repaired or replaced. Overhead protection must be provided for employees on a scaffold exposed to overhead hazards. The use of shore or lean-to scaffolds is prohibited. Materials being hoisted onto a scaffold must have a tag line. Tools, materials and debris must not be allowed to accumulate in quantities that could cause a hazard.
Specific Requirements for Common Scaffolds
Tube and Coupler Scaffold
Dimensions - Uses 2 to 2 1/2 inches O.D. steel tubing with a 6-foot maximum width and the length between vertical posts determines duty load rating. Light duty loads can use a 10-foot spacing maximum between vertical posts. Medium duty loads can use 8 feet spacing maximum between vertical posts (5 feet width with 2 inch O.D. tubing and 6 feet width with 2 1/2 inches). Heavy duty loads can use 6 feet 6 inches spacing between vertical posts. Note that light duty scaffolding cannot exceed a uniformly distributed load of 25 p.s.f., medium duty is 50 p.s.f., and heavy duty is 75 p.s.f. Maximum height of scaffolding must not exceed 125 feet unless designed by a professional engineer. Heavy duty scaffolding can have one working level. Medium duty can have a maximum of two working levels. Light duty can have four working levels. Note that transverse bracing forming an “x” across the width of the scaffold shall be installed at the scaffold ends and at least at every third set of posts horizontally (measured from only one end) and every fourth runner vertically. Longitudinal diagonal bracing is required on the inner and outside of scaffolding, running at a 45-degree angle from near the base to the top.
Tubular Welded Frames Scaffold
Loading - Follow the manufacturer’s recommendations. Proper cross bracing is required. Coupling/stacking pins are required. Vertical uplift must be prevented by suitable means (pins). Scaffold legs must be placed on adjustable bases or plain bases set on mudsills or other foundations adequate to support the maximum rated load. For scaffolding over 125 feet, design must be made by a registered professional engineer with copies of drawing and specifications available to the employer and for inspection. Daily inspections must be made of all frames and accessories, and corrections made prior to further use.
Manually-Propelled Mobile Scaffold
The height of these scaffolds must not exceed four times the minimum base dimension when freestanding. Casters must be designed to support four times the maximum intended load and be equipped with positive locking devices. Platforms must be tightly planked for the full width (except for entrance openings) and must be secured in place. A ladder or stairway must be provided. This must not introduce a tripping hazard. Scaffolds must only be moved on level floors, free of obstructions and openings. The movement force must be applied near the base of the scaffold and provisions must be made to stabilize the tower during movement. Employees must not ride on these scaffolds unless: the surface is within three degrees of level, and free from pits, holes, or obstructions; the minimum dimension of the base is at least half the height outriggers, if used must be installed on both sides); wheels must be equipped with rubber or similar resilient tires; and tools and materials are secured or removed from the platform before the mobile scaffold is moved. Each employee on the scaffold shall be made aware of the move before actually moving the scaffold. Caster stems and wheel stems should be pinned or otherwise secured in scaffold legs or adjustment screws.
Outrigger scaffolds must be designed by a registered professional engineer and be constructed loaded in accordance with the design. The inboard end must not be less than one-and-a-half times the outboard end in length. The beam must be secured in place against movement and must be securely braced at the fulcrum point against tipping. Planking must be laid tight to within 3 inches of the building face and be secured.
Training must be provided by a person qualified in the subject matter and in explaining the hazards associated with the scaffolding being used.
A. Training must inform the employees performing the work of:
• Electrical hazards
• Proper scaffold use
• Load capacities
B. Training must inform the employees involved in erecting, disassembly, and inspection of:
• Correct procedures
• Loading capacities
C. You must retrain employees because of:
• Changes in the worksite
• Changes in the equipment
• Lack of proficiency
OSHA 29CFR1926 Subpart L
WCF Insurance Safety Department
NOTICE: This guide may make reference to the Occupational Safety and Health Administration (OSHA) regulations; however the guide is not legal advice as to compliance with OSHA or other safety laws, codes, or regulations. Compliance with OSHA and other safety laws codes or regulations, and maintaining a safe work environment for your employees remains your responsibility. WCF Insurance does not undertake to perform the duty of any person to provide for the health or safety of your employees. WCF Insurance does not warrant that your workplace is safe or healthful, or that it complies with any laws, regulations, codes, or standards.