Working at Height

Under the Work at Height Regulations 2005, work is 'at height' when it takes place in any location where:

• Aa person is more than 2 metres above the ground or floor
• Ba person is working from a ladder or a scaffold platform
• Ca person is above 1.8 metres and outside a working platform
• Da person could fall a distance liable to cause personal injury✓

Answer: The regulations set no minimum height: any place where a fall could injure someone counts, including ground-level work beside an opening or excavation. The old 2-metre rule from the 1996 Regulations no longer applies and there is no threshold height, and the definition is about the risk of a fall, not the type of equipment being used.

A site manager is planning the installation of rooftop plant. Applying the hierarchy in the Work at Height Regulations, which measure should be considered before all the others?

• APreventing falls with guard rails and a working platform at the roof edge
• BMinimising the fall distance with safety nets rigged beneath the roof
• CAvoiding the work at height by assembling the plant at ground level✓
• DIssuing fall-arrest harnesses with a rehearsed rescue plan for the crew

Answer: The hierarchy starts with avoiding work at height altogether, for example by prefabricating or assembling units on the ground so fewer people go up and for less time. Guard rails and platforms prevent falls, nets and harnesses only reduce the consequences of a fall, so each of those is considered after the possibility of avoiding the work has been exhausted.

Edge protection is being specified for a working platform on a scaffold. What is the minimum height of the top guard rail above the platform?

• A1,000 mm
• B900 mm
• C1,100 mm
• D950 mm✓

Answer: Schedule 2 of the Work at Height Regulations requires the top guard rail to be at least 950 mm above the edge, with intermediate rails or other means so that no unprotected gap exceeds 470 mm; toe boards must be suitable and sufficient, and the industry standard (BS EN 12811-1 and TG20) is at least 150 mm. A 900 mm rail falls short of the legal minimum, while the higher figures exceed what is required rather than stating the minimum.

A tube-and-fitting scaffold has been in use for several weeks with no alterations or bad weather. What is the longest interval permitted between inspections by a competent person?

• A3 months
• B7 days✓
• C28 days
• D14 days

Answer: Working platforms from which a person could fall 2 metres or more must be inspected before first use and then at intervals not exceeding 7 days, with the result recorded and available on site, typically shown on a scafftag. Longer intervals leave defects such as loosened ties or missing boards undetected for too long and do not meet the regulations.

A scaffold was inspected four days ago. Overnight the site experienced gale-force winds. What must the site manager do before allowing work on it to resume?

• AAsk the scaffolding contractor to re-issue the TG20 compliance sheet
• BAllow work to continue because the 7-day inspection is still in date
• CRestrict use to the lowest lift until the next scheduled inspection
• DHave a competent person re-inspect it and record the result first✓

Answer: An inspection is also required after any event likely to have affected the scaffold's strength or stability, and high winds can loosen ties, shift boards and dislodge sheeting. The routine 7-day date does not cover this, a compliance sheet is a design document rather than a check of the structure, and using any part of the scaffold before it has been checked exposes workers to the same risk.

A leaning ladder is set up against a wall for short-duration access. At approximately what angle to the horizontal should it stand?

• AAbout 75 degrees, one unit out for every four units up✓
• BAbout 80 degrees, one unit out for every six units up
• CAbout 45 degrees, one unit out for every unit up
• DAbout 60 degrees, one unit out for every two units up

Answer: The correct set-up is roughly 75 degrees to the horizontal, achieved by placing the foot one unit out for every four units of height. A shallower angle risks the foot sliding outward and overloads the stiles, while a steeper angle makes the ladder liable to topple backwards away from the wall, especially when the user leans out.

When is it acceptable for a site manager to allow a ladder to be used as the working position for a task rather than just as access?

• AWhenever a mobile tower cannot be delivered to site the same day
• BFor any task lasting under two hours provided the ladder is footed
• CFor short-duration, low-risk tasks where a risk assessment justifies it✓
• DFor work up to 3 metres high provided three points of contact are kept

Answer: Ladders remain permitted, but only where a risk assessment shows the task is low risk and of short duration, and that other equipment is not justified. Two hours is far beyond the usual guidance of around 30 minutes in one position, delivery delays are a convenience rather than a justification, and there is no 3-metre allowance in the regulations.

A mobile tower scaffold has to be moved 10 metres along a warehouse floor. Which practice is correct?

• ALeave light tools on the platform to save time as long as they are lanyarded
• BRemove the stabilisers first so it fits, then refit them at the new position
• CKeep one operative on the platform to steady it while two people push it
• DClear people and materials off first, then move it and re-lock the wheels✓

Answer: Towers must never be moved with people or materials on the platform because a wheel catching on debris can tip the tower or throw items off. The height may need reducing and the route checked for overhead hazards, but the stabilisers stay fitted throughout and the castors are locked again before anyone climbs back up.

An IPAF-trained operator is working from a boom-type MEWP (category 3b). What personal fall protection should the site rules normally require?

• AOnly the basket guard rails, since they give adequate collective protection
• BA full-body harness with a 2-metre shock-absorbing lanyard clipped to the guard rail
• CA work-positioning belt clipped to the basket floor ring whenever the wind rises
• DA full-body harness with a short restraint lanyard fixed to the basket anchor point✓

Answer: Boom-type machines can catapult an operator out of the basket if the boom is struck or bounces, so industry guidance calls for a harness with a short restraint lanyard that stops the operator leaving the basket. A long shock-absorbing lanyard allows the person to be thrown clear and then fall, a belt does not restrain the whole body, and guard rails alone do not prevent ejection.

A roof survey identifies fibre-cement sheets and old roof lights on a warehouse where gutters need repair. Which control is appropriate for the work?

• AStaging and crawling boards to spread the load, with nets or a platform beneath✓
• BWarning signs at the eaves and a rule that operatives step only on the bolt lines
• CA harness for each operative attached to the roof light frames as anchor points
• DPainted markings on each roof light so operatives can step across them safely

Answer: Fibre-cement sheets and roof lights are fragile and will not bear a person's weight, so the load must be spread with staging or crawling boards and a fall arrested by nets or a platform underneath. Stepping on bolt lines is not a safe system, roof light frames are not tested anchors, and markings do nothing to prevent a sheet giving way.

Bricklayers are working from the third lift of a scaffold that runs alongside a busy public footpath. Which combination best protects passers-by from falling materials?

• ABrick guards and debris netting on the lifts, plus a fan or covered walkway below✓
• BSigns telling pedestrians to keep left, plus tool lanyards for the bricklayers
• CToe boards on the lifts, plus a banksman to warn pedestrians as loads are landed
• DMaterials lowered by rope rather than thrown, plus a spotter at the pavement

Answer: Where the public cannot be excluded, physical measures are needed at the source and at the receiving end: brick guards and netting stop items leaving the platform, and a fan or covered walkway catches anything that does. Toe boards alone will not stop stacked bricks, warnings and signs rely on people reacting in time, and a spotter cannot intercept a falling object.

Where fall-arrest harnesses have been chosen as the control for steel erection, what must the site manager have in place before work starts?

• AA second harness for each operative so a colleague can climb up to help
• BA permit to work that names the fire and rescue service as the rescue provider
• CA rescue plan that can recover a suspended worker promptly, rehearsed on site✓
• DA written agreement with the emergency services to attend within 30 minutes

Answer: A person left hanging in a harness can suffer suspension trauma within minutes, so the regulations require planned, practised rescue arrangements using the site's own people and equipment. Relying on the fire service is not acceptable because their response time is outside the site's control, and improvised climbing by colleagues simply creates another casualty.