A temporary prop moved from its approved position: what to do

A prop or temporary support found out of the position shown on the design is a potential collapse risk, not a quick fix. Stop work, keep people clear, and get the temporary works designer and coordinator to assess the effect before anyone reinstates it or relies on the structure.

What has happened

Someone has moved, removed or repositioned a temporary support prop, perhaps to pass materials, gain access or fit something, and the tag or design shows it should be elsewhere. Temporary works hold up a structure or excavation under a specific design; moving a prop can overload the structure, the slab or the remaining props. HSE's temporary works guidance and the Construction (Design and Management) Regulations 2015 expect temporary works to be designed, checked and controlled through a managed process (reflected in BS 5975), so an unauthorised change breaks that control and must be treated as a structural risk.

Immediate actions

Stop work in the affected area and keep people out from under and around the structure or excavation the prop supports. Do not simply push the prop back. Alert the principal contractor and the temporary works coordinator, and get the temporary works designer to assess the current condition and the effect of the change on the structure and the remaining supports. Establish whether the structure has been overloaded or damaged, and define a controlled reinstatement or remediation method. Restore access only when a competent assessment confirms it is safe.

What not to do

Do not let an operative reposition a designed prop on their own judgement, and do not assume "it was only moved a bit". Do not continue loading the slab or structure above, and do not clear the area for use before the designer confirms it. Do not fix only the visible prop if the load path or adjacent supports may also be affected.

Who is responsible

The principal contractor controls the area and coordinates the response; the temporary works coordinator manages the temporary works process; the temporary works designer assesses the change and approves reinstatement; competent operatives carry out the controlled work. Operatives must not alter designed temporary works without authorisation.

Evidence and records

Record the discovery, the exclusion, the designer's assessment and approval, the reinstatement method and any remediation, and the permit to load once reinstated, with dates and responsible people. Keep the temporary works register and design updated, and log the event so the cause can be addressed.

Escalation

Escalate a possible structural overload or damage to the designer and, where needed, a structural engineer, and keep the area closed until resolved. Where the change was driven by a material-route or access conflict, redesign that route with the same discipline as an altered scaffold changed by another trade, and where ground or excavation support is involved see trench support and ground conditions. A collapse or dangerous occurrence may be reportable under RIDDOR.

Prevention

Run a proper temporary works process: a coordinator, designed and checked propping, clear tags, permits to load and to strike, and briefings so trades know not to move supports and how to request a change. Design realistic material routes so no one is tempted to move a prop. A controlled process makes an unauthorised change rare and quickly caught.

Where Complys can help

Complys can hold the temporary works register, design and check records, permits and the incident log, and keep the discovery-to-approved-reinstatement trail together. It does not design or assess temporary works; the temporary works designer and coordinator do. Ask the Complys team to show how temporary works records and permits are tracked.