NCCER Scaffolder key terms

A temporary elevated work platform and the structure that supports it, erected so that workers can reach and work at heights, then removed when the job is finished.

Hard hats, toe boards, debris nets, and canopies used to keep dropped tools and materials from striking workers or the public below a scaffold.

Keeping platforms, walkways, and the ground beneath a scaffold clear of loose tools, scrap, and spills so workers do not trip or slip.

The minimum safe distance between a scaffold and energized electrical lines; scaffolds must be kept far enough away, or the lines de-energized, so contact or arcing cannot occur.

A flat steel plate fixed to the bottom of a scaffold standard that spreads the leg load over the sill or supporting surface.

A threaded base fitting (screw jack) under a scaffold leg that is turned to level the scaffold and fine-tune its height on uneven ground.

The vertical load-bearing tube or frame leg of a scaffold that carries platform loads down through the base plate to the foundation.

A horizontal scaffold tube running parallel to the face of the building that ties the standards together and supports the transoms.

A horizontal scaffold tube placed across the width of the scaffold, at right angles to the ledgers, that supports the platform planks.

A diagonal member fixed between standards or ledgers that keeps the scaffold square and stiff so it cannot rack or twist.

A clamp used in tube-and-coupler scaffolds to join two tubes at a fixed right angle or at any angle in a swivel type, forming rigid connections between members.

The working surface of a scaffold, made of planks, manufactured decks, or a combination, on which workers stand and set their tools and materials.

Lumber manufactured and graded specifically for scaffold platforms, free of serious defects and marked to show it meets scaffold plank requirements.

A low vertical board, typically about four inches high, fixed along the platform edge to stop tools and materials from being kicked off.

The total weight of workers, tools, materials, and equipment that a scaffold is designed and rated to carry at one time.

The weight of the scaffold itself - standards, ledgers, planks, and accessories - that the structure must support before any work begins.

The variable weight of workers, tools, and stacked materials on a platform, which changes as the work goes on.

Extra strength built into a scaffold beyond its rated load; scaffold platforms and their supports are commonly designed with a factor of about four to one.

The working load a scaffold platform is rated for, usually stated as light duty at 25, medium duty at 50, or heavy duty at 75 pounds per square foot.

A wood or steel pad placed under scaffold base plates to spread the load over a larger ground area and keep the legs from sinking.

The ground, slab, or structure that carries the scaffold's base plates; it must be firm, level, and strong enough that the loaded scaffold will not settle.

A beam or frame extension at the base of a scaffold that widens its footprint and increases stability against tipping.

The force wind exerts on a scaffold and on any netting or sheeting attached to it, which the design must resist and which can require work to stop.

A connection fastening the scaffold to a building or other rigid structure so it cannot tip or pull away, installed at spacing set by the design.

A tensioned cable or rope anchored to the ground or a structure and attached to the scaffold to keep it from leaning or overturning.

Vertical and true; scaffold standards must be set plumb within the manufacturer's tolerance so loads travel straight down the legs.

Horizontal and true; the scaffold base and each platform must be level so planks sit flat and the scaffold does not lean.

A scaffold mounted on casters so it can be rolled to a new position; brakes must be locked before use and nobody may ride it while it moves.

Taking a scaffold apart in the reverse order of erection, working from the top down, with the area below kept clear of people.

Any change to an erected scaffold, such as adding or removing a bay, plank, or tie, which only trained scaffolders following the design may make.

A person who, by training and experience, can recognize scaffold hazards and has authority to take prompt action to correct them.

A person with a recognized degree, certificate, or professional standing, or extensive training and experience, who can design scaffolds and solve scaffold engineering problems.

A barrier along an open platform edge made of a toprail, midrail, and toe board that keeps workers and materials from falling.

The highest horizontal rail of a guardrail system, normally installed about 38 to 45 inches above the platform surface, that a worker's hand can grip.

The rail of a guardrail system set about halfway between the platform and the toprail to stop a worker from falling under or through.

A body harness, lanyard or lifeline, and anchorage that together arrest a worker's fall from a scaffold and hold them until rescue.

A tag hung on an erected scaffold after inspection to show its status, such as green for safe to use, yellow for caution, or red for do not use.

A check of the scaffold, its components, ties, and platform by a competent person before each shift and after anything that may have damaged it.

A safe means of getting on and off a platform, such as a ladder, stair tower, or ramp; workers must never climb cross braces or frame members.

A climbing method in which a worker keeps two hands and one foot, or two feet and one hand, on the ladder at all times.