SSSTS Working at Height 2 — Questions and Answers
Question 1: What is the '1-in-4 rule' that applies to the positioning of a leaning (single) ladder?
- For every 4 rungs climbed, the worker must pause and reassess
- No more than 1 in 4 workers on site may use ladders at the same time
- For every 4 units of vertical height, the base of the ladder must be 1 unit out from the wall (Correct answer)
- Ladders must be inspected every 4 uses or once per day, whichever is sooner
Correct answer: For every 4 units of vertical height, the base of the ladder must be 1 unit out from the wall
The 1-in-4 rule means a leaning ladder should be placed at approximately 75 degrees — with the base 1 metre out for every 4 metres of height against the wall — to ensure stability.
Question 2: A fragile roof is identified on a refurbishment project. Which access solution is most appropriate for workers who must carry out brief inspections?
- Standard extending ladders leant against the roof edge
- Purpose-designed crawling boards or a roof access ladder distributed across the roof surface (Correct answer)
- Workers wearing anti-slip footwear moving carefully across the surface
- A single safety harness tied to a nearby chimney stack
Correct answer: Purpose-designed crawling boards or a roof access ladder distributed across the roof surface
Fragile surfaces cannot support a person's point load, so crawling boards or roof ladders that spread the load across multiple structural members must be used to prevent falls through the surface.
Question 3: According to PASMA guidance, what is the maximum height-to-minimum-base-width ratio for a mobile tower scaffold used indoors on a firm, level surface?
- 2.5:1
- 3:1
- 3.5:1 (Correct answer)
- 4.5:1
Correct answer: 3.5:1
PASMA guidance specifies that on firm, level indoor surfaces, the working height of a mobile tower scaffold must not exceed 3.5 times the minimum base dimension to prevent overturning.
Question 4: What is the key difference between a fall RESTRAINT system and a fall ARREST system?
- Restraint systems use a harness; arrest systems use a net
- Restraint systems prevent the worker from reaching an unprotected edge; arrest systems stop a fall once it has begun (Correct answer)
- Restraint systems are for use above 4 metres; arrest systems below 4 metres
- Restraint systems are collective measures; arrest systems are personal measures
Correct answer: Restraint systems prevent the worker from reaching an unprotected edge; arrest systems stop a fall once it has begun
A fall restraint system limits a worker's movement so they physically cannot reach the fall hazard, preventing the fall entirely; a fall arrest system activates after a fall begins and limits the fall distance.
Question 5: Which of the following is a critical pre-use check a site supervisor must confirm before a MEWP (Mobile Elevated Work Platform) is operated?
- That the MEWP colour matches site safety colour coding
- That the operator holds a valid IPAF operator card and that outriggers are fully deployed on firm, level ground (Correct answer)
- That the manufacturer's manual is stored in the machine cab at all times
- That the MEWP has been serviced within the last calendar month
Correct answer: That the operator holds a valid IPAF operator card and that outriggers are fully deployed on firm, level ground
MEWP operators must be trained and hold a valid IPAF card, and outriggers must be fully extended on firm, level ground before elevation to prevent overturning — the most common cause of serious MEWP accidents.
Question 6: Safety nets are used as a collective fall mitigation measure. Which statement regarding their installation is correct?
- Nets must always be installed exactly 2 metres below the working surface
- Nets must be installed no more than 1 metre below the working surface
- The required clearance beneath safety nets depends on the net type, rigging method and risk assessment (Correct answer)
- Nets must span the full site area and be inspected annually
Correct answer: The required clearance beneath safety nets depends on the net type, rigging method and risk assessment
There is no single fixed clearance distance that applies to all safety nets; the required installation parameters depend on the net specification (Type S/T/U), rigging geometry, and the site-specific risk assessment.
Question 7: What information must be recorded on a scaffold inspection report in accordance with the Work at Height Regulations 2005?
- The cost of the scaffold, the subcontractor's insurance number, and the estimated duration of use
- Name and address of the competent inspector, date and time, type and location of scaffold, and any defects found with action taken (Correct answer)
- Names of all workers authorised to use the scaffold and their training records
- The maximum permitted load and the procurement specification for the scaffold components
Correct answer: Name and address of the competent inspector, date and time, type and location of scaffold, and any defects found with action taken
Schedule 7 requires inspection reports to include the inspector's details, the date and time, type and location of scaffold, any defects identified, and the remedial action taken or required.
SSSTS Working at Height 2
What is the '1-in-4 rule' that applies to the positioning of a leaning (single) ladder?