Free STSC Scaffolding Erection and Inspection Questions and Answers 1 — Questions and Answers
Question 1: According to OSHA, who is responsible for inspecting a scaffold and its components for visible defects before each work shift?
- The site superintendent
- A competent person (Correct answer)
- Each employee who will use the scaffold
- A registered professional engineer
Correct answer: A competent person
OSHA standard 1926.451(f)(3) requires that scaffolds and scaffold components be inspected for visible defects by a competent person before each work shift and after any occurrence which could affect a scaffold's structural integrity. This ensures the scaffold remains safe for use throughout the day.
Question 2: What is the minimum height requirement for the top rail of a guardrail system on a supported scaffold?
- Exactly 36 inches
- Between 38 and 45 inches (Correct answer)
- A minimum of 48 inches
- Between 30 and 36 inches
Correct answer: Between 38 and 45 inches
Per OSHA 1926.451(g)(4)(ii), the top edge height of toprails or equivalent members on supported scaffolds must be installed between 38 inches and 45 inches above the platform surface. This height range is critical for providing effective fall protection for workers on the platform.
Question 3: When scaffold planks are overlapped to create a long platform, what is the minimum overlap distance required over the supports?
- 6 inches
- 9 inches
- 12 inches (Correct answer)
- 18 inches
Correct answer: 12 inches
OSHA 1926.451(b)(5)(i) specifies that when platforms are overlapped to create a long platform, the overlap shall occur only over supports and shall not be less than 12 inches unless the platforms are nailed together or otherwise restrained to prevent movement. This prevents the planks from slipping and creating a fall hazard.
Question 4: What is the minimum clearance distance that must be maintained between a scaffold and an insulated power line of less than 300 volts?
- 1 foot
- 3 feet (Correct answer)
- 10 feet
- 20 feet
Correct answer: 3 feet
OSHA 1926.451(f)(6) requires a minimum clearance of 3 feet for insulated power lines of less than 300 volts. For uninsulated lines or lines with higher voltages, the clearance distance increases significantly. Maintaining this distance is crucial to prevent electrocution.
Question 5: Supported scaffold poles, legs, posts, frames, and uprights must bear on which of the following?
- Compacted soil only
- Concrete blocks or bricks
- Base plates and mud sills (Correct answer)
- Stacked wood planks
Correct answer: Base plates and mud sills
According to OSHA 1926.451(c)(2), supported scaffold poles and frames must bear on base plates and mud sills or other adequate firm foundations. This ensures that the weight of the scaffold and its load is distributed evenly and prevents the scaffold from shifting or sinking into the ground.
Question 6: Under OSHA regulations, when is it permissible to use scaffold cross-bracing as a means of access?
- When the fall height is less than 10 feet
- When a qualified person determines it is safe
- When the scaffold is not yet fully loaded
- It is never permissible (Correct answer)
Correct answer: It is never permissible
OSHA standard 1926.451(e)(1) explicitly states that cross-braces shall not be used as a means of access. This is because they are not designed to support a person's weight in the same way as a ladder or stair, and using them for access can lead to slips and falls.
Free STSC Scaffolding Erection and Inspection Questions and Answers 1
According to OSHA, who is responsible for inspecting a scaffold and its components for visible defects before each work shift?