STSC Scaffolding Erection and Inspection 2 — Questions and Answers

Question 1: What is the required minimum width of a scaffold platform on a supported scaffold?

12 inches
18 inches (Correct answer)
20 inches
24 inches

Correct answer: 18 inches

OSHA 29 CFR 1926.451(b)(2) requires scaffold platforms to be at least 18 inches wide.

OSHA 29 CFR 1926.451(b)(2) requires that each scaffold platform and walkway be at least 18 inches wide. Where the work area requires a narrower platform, the platform width must be as wide as possible up to the 18-inch minimum, and guardrails and/or personal fall arrest systems must be provided. Platforms must be fully planked or decked between the front uprights and the guardrail, with gaps no greater than 1 inch (9.5 inches maximum for outrigger scaffolds used in plastering/lathing work).

Question 2: Scaffolds must be capable of supporting their own weight plus how many times the maximum intended load?

2 times
3 times
4 times (Correct answer)
5 times

Correct answer: 4 times

OSHA requires scaffolds to be capable of supporting 4 times the maximum intended load (with a 4:1 safety factor).

OSHA 29 CFR 1926.451(a)(1) requires that scaffolds and scaffold components support without failure their own weight and at least 4 times the maximum intended load applied or transmitted to them. This 4:1 safety factor accounts for dynamic loads, eccentric loading, and material variations. The maximum intended load includes workers, tools, materials, and equipment. For suspension scaffolds, the rope must sustain at least 6 times the maximum intended load (6:1 safety factor).

Question 3: When must scaffolds be inspected by a competent person?

Once per week during continuous use
Before each work shift and after any occurrence that could affect the scaffold's structural integrity (Correct answer)
Monthly and after any storm over 30 mph
At initial erection only

Correct answer: Before each work shift and after any occurrence that could affect the scaffold's structural integrity

OSHA requires scaffold inspection before each shift and after any event that could affect structural integrity (storms, impacts, modifications).

OSHA 29 CFR 1926.451(f)(3) requires that scaffolds be inspected by a competent person for visible defects before each work shift and after any occurrence which could affect the structural integrity of the scaffold. Occurrences requiring re-inspection include: high winds; impact damage; rain and freezing conditions; adjacent construction activity; and any modifications or extensions to the scaffold. The competent person must be designated by the employer and must have the authority to take prompt corrective measures.

Question 4: Access to scaffold platforms above 2 feet must be provided by:

Climbing the scaffold frame (no specific access required)
Portable ladders, direct access from another scaffold or structure, stair towers, or integral prefabricated frames (Correct answer)
Rope access only for elevated scaffolds
Boom lift to scaffold transfer only

Correct answer: Portable ladders, direct access from another scaffold or structure, stair towers, or integral prefabricated frames

OSHA requires safe access to scaffold platforms at all heights — specific acceptable access methods are prescribed.

OSHA 29 CFR 1926.451(e) requires that when scaffold platforms are more than 2 feet above or below a point of access, portable ladders, hook-on ladders, attachable ladders, stair towers (scaffold stairways/ladders), stairway-type ladders, ramps, walkways, integral prefabricated scaffold access, or direct access from another scaffold, structure, or personnel hoist must be used. Cross braces must NOT be used as a means of access. End frames may only be used as ladder access if they were specifically designed and manufactured for that purpose.

Question 5: What is the minimum setback distance from a power line required for metal scaffolding?

3 feet
5 feet
10 feet (Correct answer)
15 feet

Correct answer: 10 feet

OSHA requires a minimum 10-foot horizontal clearance from energized power lines for metal scaffolds.

OSHA 29 CFR 1926.451(f)(6) requires that scaffolds be erected, used, moved, dismantled, or altered only when the electrical hazard has been evaluated and addressed. For energized power lines, the minimum clearance is: lines up to 300 volts — 3 feet; lines from 300 volts to 50 kV — 10 feet; lines over 50 kV — 10 feet plus 4 inches for each 10 kV over 50 kV. Metal scaffolding is an electrical conductor, and any contact with energized lines creates an electrocution hazard for all workers on the scaffold.

Question 6: When erecting or dismantling scaffolding, workers must be protected from falls by a competent person who:

Stands at the base and shouts warnings
Determines the feasibility and safety of providing fall protection and implements it accordingly (Correct answer)
Calls OSHA before each erection or dismantling activity
Holds a ladder for each worker as they climb

Correct answer: Determines the feasibility and safety of providing fall protection and implements it accordingly

A competent person must evaluate the feasibility of fall protection during erection/dismantling and implement appropriate measures based on that evaluation.

OSHA 29 CFR 1926.451(g)(2) requires that a competent person determine the feasibility and safety of providing fall protection for erection and dismantling of scaffolds. If fall protection is feasible, it must be provided. If not feasible (because it creates greater hazards or is technically impossible at that stage), the competent person must document why. The competent person must be present and directing the erection/dismantling activity. Workers must not be exposed to fall hazards during these activities unless the competent person has determined that protection is not feasible.

STSC Scaffolding Erection and Inspection 2

What is the required minimum width of a scaffold platform on a supported scaffold?