Skip to main content

CROSS Safety Report

Reduced partition loads on proprietary joists

Report ID: 108 Published: 1 July 2008 Region: CROSS-UK

This report is over 2 years old

Please be aware that it might contain information that is no longer up to date. We keep all reports available for historic reference and as learning aids.


A reporter believes that a number of proprietary joist manufacturers are using a reduced partition allowance for the engineered joist design.

Key Learning Outcomes

For civil and structural design engineers:

  • Where it is shown that the actual weight of a partition exceeds the loads given in standards and codes of practice, the actual weights should be used

Full Report

Find out more about the Full Report

This section contains the Full Report submitted to CROSS and describes the reporter’s concerns or experiences. However, the text has been edited for clarity, and identifiable details have been removed to ensure anonymity and confidentiality. If you would like to know more about our secure reporting process, or submit a report yourself, please visit the reporting to CROSS-UK page.


A reporter believes that a number of proprietary joist manufacturers are using a reduced partition allowance for the engineered joist design. The load used is quoted in the code of practice for engineered wood products. Whilst carrying out structural checks on several designs the reporter noticed that the load allowance is less than he would normally have used. They are concerned that this may be missed by contractors commissioning the floor design without an engineering check on the assumptions that have been made and wondered if anyone else has observed this too?

Expert Panel Comments

Find out more about the Expert Panels

Expert Panels comment on the reports we receive. They use their experience to help you understand what can be learned from the reports. If you would like to know more, please visit the CROSS-UK Expert Panels page.

It is assumed that the code of practice referred to is, 'Engineered Wood Products - Code of Practice' by the UK Timber Frame Association (January 2007). This applies primarily to new residential buildings and structures, although it states that the principles can be applied to other classes of structure. The minimum load for non-load bearing partitions, applied to single occupancy domestic floors is given as the more onerous of 0.64kN/m line load or 0.22kN/m2 uniformly distributed load (UDL). 

The weight of a timber stud partition with 12.5mm plasterboard both sides is given as 27kg/m2 in TRADA Technology Timber Frame Housing: UK Structural recommendations. For a wall 2.4m high, this equates to around 0.64kN/m, as above. The document goes on to say that the floor designer is responsible for determining the partition loads on a floor. 

Where it is shown that the actual weight of partition exceeds the loads given, the actual weights should be used. It also states that reference should be made to BS 6399-1 or BS EN 1991-1-1 for partition loads for floors of other than single occupancy domestic dwellings. Where partitions are envisaged, but their location is not known, an allowance of 1/3 of the load/m run of the finished partition should be applied as a UDL. This is consistent with the above. However, for office floors this UDL should not be less than 1.0kN/m2. The load to be applied thus depends upon the use of the building.

Submit a report

Your report will make a difference. It will help to create positive change and improve safety.

Our secure and confidential safety reporting system gives professionals the opportunity to share their experiences to help others.