NEBOSH CC Working at Height in Construction — Questions and Answers
Question 1: Under the Work at Height Regulations 2005, what is the first step in the hierarchy for managing the risk of working at height?
- Avoid work at height where it is reasonably practicable to do so (Correct answer)
- Use collective fall prevention measures such as guardrails
- Use personal fall protection equipment such as harnesses
- Minimise the distance and consequences of a fall
Correct answer: Avoid work at height where it is reasonably practicable to do so
The Work at Height Regulations 2005 establish a clear hierarchy: first avoid work at height altogether (e.g., assemble at ground level then crane into position); if unavoidable, use work equipment to prevent falls (guardrails, scaffolds); then minimise fall distance and consequences (safety nets, airbags).
Question 2: How often must a scaffold be inspected under the Work at Height Regulations 2005?
- Before first use, at intervals not exceeding 7 days, and after any event likely to affect stability (Correct answer)
- Monthly
- Every 14 days
- Only before first use
Correct answer: Before first use, at intervals not exceeding 7 days, and after any event likely to affect stability
Scaffolds must be inspected by a competent person before first use, at intervals not exceeding 7 days thereafter, and after any event (such as high winds, alteration, or damage) that could affect stability or integrity. Written inspection reports must be kept on site.
Question 3: What is the minimum guardrail height required on a scaffold working platform?
- 950 mm above the working platform (Correct answer)
- 750 mm above the working platform
- 1100 mm above the working platform
- 500 mm above the working platform
Correct answer: 950 mm above the working platform
The Work at Height Regulations 2005 require a top guardrail at a minimum height of 950 mm above the working platform. There must also be an intermediate guardrail or equivalent (so no gap exceeds 470 mm) and a toe board of at least 150 mm height to prevent materials falling.
Question 4: A worker needs to access a roof to carry out a brief inspection lasting approximately 15 minutes. What is the most appropriate form of access?
- A mobile elevated work platform (MEWP) providing edge protection at roof level (Correct answer)
- An unsecured ladder leaning against the gutter
- Climbing up the scaffolding poles
- Using a rope thrown over the ridge
Correct answer: A mobile elevated work platform (MEWP) providing edge protection at roof level
A MEWP (cherry picker) provides a safe working platform with built-in guardrails, is suitable for short-duration tasks, and can position the worker at the correct height without requiring them to step onto the roof. Ladders should only be used for access to height, not as a work platform, unless the task is very short and low-risk.
Question 5: What is a 'fragile surface' as defined in the Work at Height Regulations 2005, and why is it significant?
- A surface that would be liable to break if a person's weight were applied, requiring specific precautions to prevent falls through it (Correct answer)
- Any surface above 2 metres
- A surface that has been damaged by weather
- A newly painted surface that is still wet
Correct answer: A surface that would be liable to break if a person's weight were applied, requiring specific precautions to prevent falls through it
A fragile surface is one liable to fail if a person's weight is applied, including materials such as fibre cement sheets, glass rooflights, corroded metal sheeting, and liner panels. The regulations require prominent warning notices, prevention of approach, and if work on or near fragile surfaces is unavoidable, suitable platforms and fall protection.
Question 6: When using a safety harness as personal fall protection on a construction site, what is the critical importance of calculating the total fall distance?
- To ensure there is sufficient clearance below the working position to arrest the fall before the worker strikes a lower level (Correct answer)
- To determine the correct harness size
- To calculate the worker's insurance premium
- To decide whether a helmet is also needed
Correct answer: To ensure there is sufficient clearance below the working position to arrest the fall before the worker strikes a lower level
Total fall distance includes free fall distance, lanyard/energy absorber deployment length (typically 1.75m), harness stretch, and the worker's height below the attachment point. If the clearance below is insufficient, the worker will strike the ground or structure despite the harness arresting the fall.
