Scaffolding Safety Getting It Right
Words: Steven AdamsIndustry statistics indicate that at least 30 percent of all scaffold-related accidents involve the misuse of mobile scaffolds, commonly referred to as rolling towers. Although circumstances differ in each accident, one recurring error seems evident: in the majority of accidents, a complete mobile scaffold is not utilized.
On October 24, 2001, a fourteen-story scaffold, which was being used to replace a brick facade on a building in New York City, collapsed. The result: five workers were killed and 11 others seriously injured. Although the facts and circumstances surrounding this tragedy have yet to be determined, one observation seems particularly relevant: scaffold being used in a masonry application presents unique challenges for the "competent person" and those under his authority.
The Occupational Safety and Health Administration (OSHA) has strict regulations concerning the proper assembly and usage of masonry scaffolds. Unfortunately, the erector and/or laborer often perceive certain components as unnecessary or too expensive to rent or buy. The result is a scaffold that does not comply with the OSHA standards.
Whether you are renting extra sections for a big job, buying new or used equipment, or just inventorying your existing equipment, there are numerous areas of compliance that should be checked to be certain you have all the necessary components to satisfy OSHA.
The most commonly "forgotten" scaffold components are:
Base Plates and Mud Sills: Base plates and mud sills are required on all scaffolds. Also, the surface on which the mud sills are placed must be capable of supporting the loaded scaffold without settling. In some cases it may be necessary to compact the soil before setting up the scaffold.
Scaffold Ties: The first tie must be installed at the horizontal member of the frame closest to the 4:1 base to height ratio. In other words, if you are utilizing 5-feet wide frames, the first tie should be installed at the horizontal member of the frame as close to the 20-feet height as possible. After the initial tie is installed, subsequent ties must be installed at height intervals not to exceed 26 feet. Also, ties must be installed at each end of the scaffold and at horizontal intervals not to exceed 30 feet. All ties should be capable of withstanding a "push" or "pull" force of 2,500 pounds. Additional ties may be necessary when enclosing a scaffold or when the scaffold is subject to high winds. If in doubt, always review your scaffold set-up plans with a professional engineer prior to beginning the set-up.
Side Brackets: When using side brackets, it is important to remember that brackets are for personnel only. NEVER use side brackets for material loading or storage. Also, check the load capacity of the side brackets and do not overload them. Most brackets are rated for a load capacity of 500 pounds. When determining the load on a particular bracket, you must remember to include the load in the area of .5 of the bay on each side of the bracket. Side brackets should be secured against uplift by either pinning (if holes are provided) or wiring to the frame.
Guard Railing: This should be complete with both top rails and mid rails. Current OSHA scaffold codes require fall protection on all scaffolds where the user is exposed to a fall of 10 feet or more to a lower level. When using guard railing to satisfy the fall protection requirement, it must be installed with a top rail height of between 38 inches and 45 inches above the work platform. Mid rails must be installed approximately midway between the top rails and the work platform. Also, all top rails must be able to withstand a force of 200 pounds in any downward or horizontal direction. Don't forget guard rail panels on the side brackets at each end of the scaffold.
Toeboards: Current OSHA scaffold codes require toeboards on all sides of the work platform at heights of 10 feet or greater. Toeboards must be a minimum of 3.5 inches high and be able to withstand a force of at least 50 pounds applied in any downward or horizontal direction.
Work Platform Decking: OSHA requires all work levels to be completely decked. Always follow the OSHA chart to determine platform load capacity when using plank. When manufactured plank or decks are used, be careful not to exceed the rated load capacity. Also be sure to properly inspect all planks/platforms before installing, and once installed, check for proper overlap of the planks.
Fastening (Lock) Pins: The most popular types are snap pins, gravity pigtail pins, and hinge pins. These are recommended at all frame connections, especially if hoisting material from the platform level.
If you are dealing with a rental center, and as a customer you refuse to rent any or all of these items, the rental center is faced with a difficult dilemma: either require you, the customer, to rent the necessary components, risking loss of rental; or knowingly allow you to assemble and use the scaffold in a manner that does not comply with existing regulations. In either case, the rental center can lose.
The answer is that safety must take priority. Although you may not like the extra costs involved with the extra components, in the long run, your employees will appreciate your concern for their safety.
In the end, safety must be made a top priority, but it must begin in the front office before the first piece of scaffold ever leaves the yard.