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604 Scaffold Safety
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604 Scaffold Safety

Scaffolding Terms

It's important to know some of the common terms when dealing with scaffolding. For example, when an employee goes from one job site to another, knowing the proper scaffolding terms will improve communications and safety.

Workers hoisting pallet onto scaffold from the roof.
Hoisting a pallet on to the scaffold.

Scaffold Terms

  • Adjustable suspension: A secure point of attachment for lifelines, lanyard, deceleration devices, or tiebacks.
  • Bearer: A horizontal member of a scaffold upon which the platform unit rests and that may be supported by runners.
  • Brace Plate: A device used to distribute vertical load.
  • Boatswains' Chair: A suspended seat designed to accommodate one worker in a sitting position.
  • Body Harness, Full: Straps that are secured about an employee in a manner that distributes the arresting forces over at least the thighs, shoulders and pelvis with provisions for attaching a lanyard, lifeline or deceleration device.
  • Brace: A device that holds one scaffold member in a fixed position with respect to another member.
  • Competent Person: A person who can identify existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous, or dangerous to employees, and who has the authority to take prompt corrective measures to eliminate such hazards.
  • Cross Braces: Two diagonal scaffold members joined at their center to form an "X." Used between frames or uprights or both.
  • Design Load: The maximum intended load of a scaffold; The total of all loads including the worker(s), material and the equipment placed on the unit.
  • Electrical Ground: A conducting connection between an electrical circuit or equipment and the area, or some conducting body that serves in place of the earth.
  • Fall Protection: A system designed to prevent or arrest a person's fall.
  • Guardrail System: A rail system erected along the open sides and ends of platforms. The rail system consists of a toprail and mid-rail and their supports.
  • Guy: A rope, chain or cable used to stabilize a vertical object.
  • Hoist: A device intended to be used to raise and lower a suspended scaffold. It may be manually operated or power operated.
  • Lanyard: A flexible line to secure the wearer of a full body harness to a lifeline, trolley line or a fixed anchor.
  • Maximum Intended Load: The total load of all workers, equipment, tools, and materials.
  • Midrail: A rail approximately midway between the toprail and platform of a guardrail system.
  • Open Sides and Ends: That portion of a scaffold platform unit that is not protected by a guardrail system, cross braces, vertical work surfaces, or stirrups.
  • Personal Fall Arrest System: An assembly of components and subsystems used to arrest a person in a fall from a working height.
  • Plank: A wood board and fabricated component that serves as a platform unit.
  • Plank (Metal): A metal platform united in size to support one or more workers or uniformly distributed loads. Metal planks would be similar dimensions as wood planks.
  • Plank (Wood, Laminated): A platform unit of glue-laminated wood whose method of manufacture and assigned design values contemplates flat use in a scaffolding application.
  • Plank (Wood, Sawn): A board of sawn lumber whose grading rules and assigned design values contemplate flat use in a scaffolding application.
  • Platform: A work surface elevated above lower levels. Platforms can be constructed using individual wood planks, fabricated planks, fabricated decks, and fabricated platforms.
  • Qualified Person: A person who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training or experience has successfully demonstrated the ability to solve or resolve problems related to the subject matter, the work or the project.
  • Rated Load: The manufacturer's recommended maximum load.
  • Runner: A horizontal scaffold member that forms a tie between posts and may also support a bearer.
  • Safety Screen: A wire or plastic screening that protects the workers and passers-by below from dropped items.
  • Scaffold: A temporary elevated or suspended work unit and its supporting structure used for supporting worker(s) or materials, or both.
  • Sill: A footing (usually wood) which distributes the vertical loads to the ground or slab below.
  • Tie: A device used between scaffold component and the building or structure to enhance lateral stability.
  • Toeboard: A barrier secured along the sides and the ends of a platform unit to guard against the falling of material, tools and other loose objects.
  • Toprail: The uppermost horizontal rail of a guardrail system.
  • Working Load: Load imposed by persons, materials and equipment.

For a more complete list of definitions, see OSHA's 1926.450, Scaffolds.

Knowledge Check Choose the best answer for the question.

1-4. Which of the following scaffold terms means a work surface elevated above lower levels?

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