01 Oct Scaffold Inspections
Scaffolding is a temporary, field erected structure used for working aloft. Because it is temporary and field erected, it is subject to wear and abuse, improper assembly, and unauthorized changes. Construction standards require that a “competent person” inspect scaffolds for defects before every work shift. Yet, in all industries, every employee who works on or around scaffolding should be aware of safety requirements. The following list includes things to watch for:
- Scaffolding must be erected on firm footing capable of carrying the maximum intended load. Boxes, barrels, loose concrete blocks or brick must not be used to support the structure.
- Consideration must be given to the weight the scaffold is to carry. It must be capable of supporting, without failure, four times the maximum intended load. The load includes not only the weight of the people on the scaffold but also any supplies and equipment being used.
- Scaffolding is naturally unstable because it is usually a tall structure with a narrow base. To counteract this, the scaffold must be braced or tied off to a stable structure such as a ship’s hull or building wall.
- The planking used must be “scaffold grade.” The wood must be clear, free of loose knots, splits, or other defects. To create a proper work surface, generally 2 planks need to be laid side by side to create a 20″ wide work platform. At the ends, the planking must overlap at least 6″ but no more than 18″ (limited to 12″ for shipyards and construction) unless the planks are fastened to the supporting members.
- Toeboards at least 4″ high (3 ½” for construction) should be installed along the outer scaffold edge, to prevent tools or materials from falling onto workers below.
- Guardrail requirements for supported scaffolds vary for different industries. The federal OSHA standard for construction and general industry requires guardrails when a platform is 10 feet or higher. In shipyards, they must be installed if the work platform is 5 feet or more above a solid surface, or at any distance above water. Some State codes may set the height at 6 feet. You must know the rule for your state or jurisdiction.
- Guardrails are usually made of 2×4 lumber or steel pipe. The top rail should be about 42″ above the scaffold walking surface, with a “mid-rail” at about 21 inches. Fiber or wire rope can be used if it is attached to rigid supports and kept taut. However, a variance may be needed to do so in some jurisdictions. It should be noted that the railings must be of adequate strength to restrain someone who has started to fall.
- Railings can be omitted if a structure, such as a ship’s hull prevents their use. However, in these circumstances, you must wear a safety harness and lifeline if you working more than 5 feet above a solid surface. If over water, you must wear an approved buoyant work vest.
Finally, never make any changes to scaffolding yourself. Only designated “Competent Persons” should make modifications.