A Year in Reports: The top 10 most read CROSS Safety Reports of 2023 (Part 1)

Goodbye to 2023! From RAAC, to CLT to Battery Energy Storage Systems; join us as we countdown some of our most viewed Safety Reports of the last twelve months, including a few you may have missed the first time around.

10. Overloading a portal frame with suspended services

We start the countdown with this report from August. A reporter designing a single storey portal frame used a standard roof service loading of 0.25kN/m2. After the project was completed, a tenant for the unit took over fit out and proposed to install sprinkler pipework which would have resulted in a considerable additional load.

The lesson is that the weight of suspended service pipes full of liquid may exceed nominal allowances and designers should be kept informed of changes on site.

9. RAAC planks in a 1970s shopping centre

The first (but by no means last) RAAC report in the top 10. A large shopping centre built circa 1975 had a number of external storerooms and loading bays with roofs constructed using reinforced autoclaved aerated concrete planks. The planks had deflected to the extent that they needed replacing.

For more information on RAAC see our Theme page.

8. The risk of collapse of multi-storey CLT buildings during a fire

One of our most read reports in 2023 but published two years ago. In March 2021, a reporter presents concerns about the fire safety of multi-storey buildings comprised of cross-laminated timber (CLT) structures. These concerns suggest to them an unacceptable risk of collapse in the event of an uncontrolled fire.

It was recommended that the use of CLT in multi-storey buildings should be reviewed at the design stage by fire and structural engineers with knowledge of its use.

7. Incorrectly installed tension control bolts could have led to serious consequences

A reporter finds incorrectly installed system HRC preload bolt assemblies, better known as tension control bolts, during a site inspection of a new highway bridge over a railway. The incorrectly fitted bolts could have had major structural implications and led to other safety risks had the issue not been identified.

This emphasised the importance of checking critical connections during and after installation.

6. Incompetent design of steel beams

Published in May, this report concerns designs for simple steel beams submitted to building control bodies under Part A of the Building Regulations. The reporter was not able to accept the effective length and restraints assumed in a number of submitted designs. Most originated from individuals who used proprietary structural design computer packages without, in the view of the reporter, a sufficient understanding of the subject.

Typical of many such reports it demonstrates that designers must understand the principles of the problem at hand, and the relevant design codes, before using software.

Part two of our countdown, featuring numbers 5 to 1 will be published on Thursday 28th December.