NCCER Scaffolder cheat sheet

OSHA 29 CFR 1926 Subpart L is the construction scaffold standard; falls are the leading cause of fatalities in scaffold work.

Fall protection is required for any employee on a scaffold 10 ft or more above a lower level (1926.451(g)(1)).

Erection, moving, dismantling, and alteration of scaffolds must be supervised by a competent person who can identify hazards and has authority to correct them.

Minimum approach distance to power lines: 10 ft for insulated lines under 50 kV, 15 ft for uninsulated lines under 50 kV, plus 0.4 in per kV above 50 kV.

Tag system decision rule: green = safe for use, yellow = caution/limited use, red = do not use.

Guardrail top rail must be 38 to 45 in above the platform; the midrail is placed midway between the top rail and the platform surface.

Toeboards must be at least 3.5 in high wherever tools, materials, or debris could fall to a lower level.

Scaffolds must be re-inspected after storms or high winds, and use must stop when weather exceeds manufacturer limits or the scaffold becomes unstable.

Barricade the area below erection, dismantling, and overhead work; falling objects are a primary struck-by hazard on scaffold sites.

Common fabricated frame bay sizes are 5 ft wide by 7 ft long; frames stack using coupling pins with spring clips or locking devices.

Tube and coupler scaffolds use 1.5 in nominal pipe (1.69 in OD); right-angle couplers fix a 90-degree joint, swivel couplers set any angle, and sleeve couplers join tube ends in line.

A base plate is required under every frame leg; adjustable screw jacks level the scaffold and their exposed thread is limited by the manufacturer.

Mud sills, typically 2 in thick by 10 in wide lumber, spread scaffold leg loads over soil or soft surfaces.

Maximum span for scaffold-grade solid sawn planks: 2x10 = 10 ft, 2x8 = 8 ft, 2x6 = 6 ft.

Planks must overlap at least 12 in over a support and must be secured against sliding or displacement.

Cross braces are installed on the ends of each bay to provide lateral stability and keep frames square; they are never used as a means of access.

Defective component rule: bent, cracked, severely rusted, or otherwise damaged parts are removed from service rather than straightened or field-repaired.

Every scaffold and scaffold component must support, without failure, its own weight plus at least 4 times the maximum intended load.

Suspension ropes and straps must support at least 6 times the maximum intended load.

Duty ratings for maximum intended load: light duty = 25 psf, medium duty = 50 psf, heavy duty = 75 psf.

Freestanding height rule: scaffold height must not exceed 4 times its least base dimension unless it is guyed, tied, or designed by a qualified person.

Foundations must be firm, level, and continuous; no leg may bear on uncompacted fill, ice, or soft ground without a load-spreading sill or pad.

Approximate leg load = total dead load plus live load divided by the number of legs; compare the result to the bearing capacity of the footing.

Racking (lateral sway) is resisted by cross braces, diagonal bracing, and ties connecting the scaffold to the structure.

Wind produces overturning and uplift forces; netting or sheeting increases sail area and therefore requires more or stronger ties.

Typical erection sequence: sills and base plates, frames, cross braces, level and plumb, ties, platforms, guardrails and toeboards, then access.

Dismantling follows the reverse of the erection sequence, working from the top down.

Working platforms must be at least 18 in wide, with gaps between planks and between planks and uprights not exceeding 1 in.

Components are lowered by rope, hoist, or hand during dismantling; they are never thrown or dropped from the scaffold.

No alteration without competent-person approval; ties, braces, and guardrails are never removed without providing equivalent temporary protection.

Platforms must be cleared and workers removed before a rolling or mobile scaffold is moved; employees may not ride a moving scaffold.

The area below must be barricaded and access restricted before erection or dismantling begins.

Standing on frame tops, guardrails, or unsecured planks to reach higher work is prohibited; use the scaffold's designated access.

A competent person must inspect the scaffold and components before each shift, after any alteration, and after storms or high winds.

Access is required whenever a platform is more than 24 in above or below a point of access; cross braces are never a means of access.

Ladders used for scaffold access must extend at least 3 ft above the landing surface and be secured against movement.

Guardrail systems (top rail 38 to 45 in, midrail, toeboard) are the primary fall protection; personal fall arrest is used where guardrails are not feasible.

Fall arrest anchorage must support at least 5,000 lb per employee or be designed with a safety factor of at least 2 by a qualified person.

Lanyards attach to a scaffold structural member or a vertical lifeline, not to a guardrail or standoff bracket, unless the manufacturer specifically permits it.

Training must be delivered by a qualified person and cover hazard recognition, load limits, erection and dismantling, and fall protection; retraining is required when conditions or equipment change.

A scaffold found defective during inspection is tagged out of service and remains unusable until repaired and re-inspected by qualified personnel.