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Time to reconsider the manual unloading of trussed rafters  

30th May 2023
Site workers looking at trussed rafters on lorry

The TRA always recommends mechanical handling for the unloading of roof trusses; however, where contractors choose not to use mechanical handling, TRA members are being recommended to adopt a new lower maximum weight limit of 75 Kg per truss for these deliveries.

We spoke to Ed Kirk from the TRA’s health and safety committee about his thoughts on why this change is necessary in advance of publishing the TRA’s new guidance. 

“The Manual Handling Operations Regulation 1992 sets out a clear hierarchy of measures that must be followed to prevent and manage the risks from hazardous manual handling; this includes: 

Avoid hazardous manual handling operations

This is why the TRA always recommends mechanical handling for the unloading of roof trusses.

Assess the risk of injury to workers from any hazardous manual handling that can’t be avoided

This is the site-specific risk assessment that must be undertaken by contractors before asking a trussed rafter manufacturer for a manual unload delivery.

Reduce the risk of injury to workers from hazardous manual handling to as low as reasonably practicable

This is the critical factor which must be considered by contractors when designing a site-specific safe system of work. In the case of trussed rafters, it is not only the maximum weight that must be considered but also the height and type of truss that is important.  

It is crucial that the manual lifters do not exceed their lifting capacity and with the HSE recommended maximum of 25 Kg per person it is important to consider how this relates to the number of people in a lifting team and how effectively they can work together.

At present, a team of four lifters are needed to achieve the current maximum total weight of 95kg. This can create an issue with tall or unusually shaped trusses as the weight distribution will not be even, resulting in some handlers bearing more weight than others. 

We believe by reducing the maximum weight that is delivered for manual unloading; it will mean that contractors have a much better chance of effectively addressing the communication and weight distribution issues that are associated with trussed rafters, particularly those that are tall or unusually shaped like raised tie trusses. 

Heavier loads

Unfortunately, it is not just the risk of musculoskeletal disorders (MSDs), that must be considered when contemplating manually unloading trussed rafters.

Due to their height and dynamic instability, when not appropriately restrained, there is also a risk of crush or other physical injury. Mechanical handling equipment, as well as eliminating the MSD risk, also provides much better restraint to prevent trussed rafters falling and injuring site staff or drivers.” 

The TRA is currently updating its safety leaflet for members, which will be available for members during July. 

For more information on handling storage and installation, see the TRA Roadmap here.


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Trussed Rafter Association