Construction manual handling: Blocks and masonry units
Blocks and other masonry units are common construction products. Regularly handling heavy units can present significant risks of developing musculoskeletal problems. This page tells you how to control this risk and why. You also need to be aware of the general information on manual handling.
What you must do
Follow the Assess, Control and Review model. Pay particular attention to the following things:
Identify and assess: Lifting and handling blocks is a highly repetitive task. It can also involve twisting, stooping or reaching upwards. The risk of injury increases with the weight of the block and when laying above shoulder / below knee height. Also consider job demands or time pressure. This may mean workers do not have enough rest / recovery time. Workers are particularly at risk if they are repetitively handling blocks heavier than 20 kg. Follow the control steps below.
Follow the general precautions for controlling lifting and carrying risks. In addition, you should also consider the issues below.
Prevent: Think about limiting the risks before work starts by:
- considering different construction methods (eg a panel wall system, cluster laying or poured concrete foundations instead of block laying)
- selecting the lightest block that meets the performance criteria for the design. Pay particular attention to ensuring blocks over 20kg are not included within the design / specification where possible (eg – by laying thinner dense blocks flat instead of thicker dense blocks upright or using lighter trench blocks with handholds.
Control: Even if you minimise some of the risks this way, you are still likely to have to lay blocks. Control the risk by following the information below.
- Setting out – avoid handling the blocks as much as you can. Get them delivered as close as possible to the point of use (eg make sure there are enough loading bays). Check they are set down on level ground – preferably without double stacking. Use pallet trucks, trolleys etc where possible if you need to move blocks around the site. Otherwise handle / carry blocks close to the body. Do not carry them up ladders. Arrange the work area to avoid over-reaching or twisting – eg by ensuring easy access to all sides of the block stack.
- Laying height – set working platforms etc so that block laying can take place between chest and knee height. Workers laying in this range should typically be able to safely lay blocks under 20kg at a rate of between 20-30 blocks an hour. Reduce the weight of the block or the laying frequency if you are working outside this range. Widen foundation trenches so that you can lay blocks within it rather than stooping below foot level.
- Mortar spot boards – set these at a comfortable height so that you do not need to bend all of the time or reach too far.
- Dense and specialist blocks – use mechanical handling solutions where possible. Relying on two people to handle blocks heavier than 20kg is not usually a suitable solution to the risk.
- Gloves – consider wearing appropriate gloves when handling blocks to protect against cuts and abrasions from sharp edges. These will also protect your hands against cement / mortar risks when laying the blocks.
Supervise: Check site working practices to ensure that the correct controls are being used. Keep routes free of obstructions to prevent slips and trips.
What you should know
MSD injuries from handling heavy concrete and stone block products do not usually occur because of a ‘one-off’ lift. The injuries usually arise from ongoing repetition of the work and posture during the lifting. These factors can create excessive stresses and strains on the body, which can cause damage to muscles and tendons. Workers are particularly at risk if they are repetitively handling blocks heavier than 20 kg.