What should you do when another trade alters a scaffold?

When you find that a tie, guard rail or transom has been moved or removed by another trade, stop use of the affected scaffold, prevent access, and get a competent person to establish its condition and the corrective method before anyone works on it again. An earlier handover or inspection record does not certify the altered structure.

The scaffold was handed over, then someone changed it

A crew arrives on a scaffold inspected two days ago. A transom has been removed so materials can pass through, a guard rail is laid on the platform and a tie appears loosened beside the opening. The tag still shows the earlier inspection date, and no one can say who made the change or whether anyone used the structure afterwards. The earlier record does not cover this condition. Stop use of the affected scaffold and prevent access until a competent person establishes its condition and the corrective method. HSE scaffold guidance says scaffolds must be designed, erected, altered and dismantled by competent people under competent supervision, checked whenever substantially altered or adversely affected, and that a scaffold unavailable for use should be marked and physically delineated to prevent access to the danger zone.

Do not assume the missing part is minor. A guard rail protects against falls, a tie restrains the structure and a transom can carry deck loads or provide structural support. The effect depends on the design, load class, configuration and stage of work. A worker who knows how to put a tube back may still lack the design information or authority to decide the scaffold is stable and usable. This guide owns the discovered unauthorised change and safe return; the live Complys scaffold handover guide and scaffolding compliance guide own initial handover and broader requirements.

Stop access to the affected scaffold

Tell workers to stop the affected activity and use a safe route off the scaffold if one remains. Do not direct anyone across an unstable platform or past a missing guard rail to retrieve tools; if the exit route is in doubt, use the site's emergency arrangements and obtain competent advice. Keep people below clear of falling-object and possible collapse zones. The exclusion may need to cover adjacent bays or the ground outside the site, especially where the scaffold is tied into a building or stands above a public route.

Control every access point. Remove or secure access where it can be done safely, place clear warning signs and provide a physical boundary that stops another crew entering by mistake. A changed tag alone is not enough if a worker can step onto the platform from a window or adjoining lift. Inform the principal contractor, scaffold contractor, scaffold user or hirer, and the temporary works coordinator where the project uses one, so the site-wide effect (work below, vehicle routes, other scaffold users, public protection) is coordinated rather than left to each trade. Set an exact status, for example "East elevation scaffold lifts three to five closed after unauthorised alteration; no access, loading or hoist use pending competent assessment," and make it visible at the workface and in the shift handover.

Find out what changed without creating another hazard

Obtain the latest scaffold design or recognised standard configuration information, handover record, inspection reports and alteration instructions, and confirm the version that applied before the change. A scaffold with a bespoke beam, fan, loading bay or facade support may have restrictions that are not apparent from its appearance. Build a chronology from safe observations: which component is absent or moved, whether it is damaged, when the structure was last confirmed intact, which trades used it since, and whether heavy materials were stacked, hoisted or moved through the opening. Record uncertainty rather than inventing an exact time.

Photographs can help, but workers should not enter a dangerous zone to take them; the scaffold contractor or engineer may need to inspect from another access route or an agreed safe method. Preserve the previous inspection report as history and do not edit it to imply it covered the later altered condition. Ask why the component was moved, because merely putting it back can recreate the conflict and invite another unauthorised change; a designer may need to provide a planned temporary opening or a different material route that serves the task without sacrificing scaffold integrity.

Put the assessment with competent people

The scaffold contractor, competent scaffolder, designer and inspector should determine the response for the specific structure. A proposed modification that takes a scaffold outside a recognised standard configuration must be designed by a competent person and proven by calculation. Do not assume that someone qualified to inspect a simple access scaffold can approve a complex designed alteration; competence depends on the type and complexity of the structure and task, and the inspector may need the designer's advice on tie forces, loaded bays, sheeting, cantilevered sections or facade restraint. HSE warns that an ordinary access scaffold is not automatically suitable for facade retention. HSE scaffold guidance.

Check whether the altered condition created loads or damage that remain after the part is returned. A missing tie may have allowed movement, a removed transom may have redistributed deck load and a guard-rail removal may have exposed workers to a fall, so the assessment may require checking neighbouring components and anchors, not only replacing the visible part. Keep authority lines clear: the site supervisor can stop work and coordinate exclusion immediately, the scaffold contractor can perform competent alteration, the designer resolves design changes, and a competent inspector must assess the scaffold before renewed use. A signature from someone outside their competence does not resolve the technical question.

Correct the scaffold under a controlled method

The correction plan should state which components are to be reinstated or redesigned, who will do the work, how they will access the scaffold safely, what loads must be removed, whether a hoist or adjacent work must stop, and how people below will be protected. Keep the affected scaffold unavailable for ordinary use during the alteration, marked and physically delineated so people cannot enter the danger zone. If the original configuration can safely be restored, follow the applicable design or standard configuration and check that components and fixings are suitable; if the task genuinely needs an opening, have a competent designer or scaffold contractor plan an authorised solution rather than leaving a "temporary" gap open across several shifts.

Inspect components removed by another trade before reuse: a bent tube, damaged fitting or compromised anchor should not go back merely to restore the drawing. Confirm the remaining scaffold was not overloaded or used outside its rating during the deviation, and record the actual work carried out and any variation from the planned method. Where work on the scaffold creates a public exposure, strengthen the ground-level exclusion or diversion; HSE public-protection guidance highlights falling objects, scaffolds and access equipment near public boundaries, and work should not restart above an occupied footway until its protection is suitable.

Reinspect and hand back the right condition

The scaffold user or hirer must ensure the scaffold is inspected before renewed use. HSE confirms inspection on completion, at least weekly (intervals no longer than seven days), after bad weather and always after any modification, under the Work at Height Regulations 2005. Do not wait for the next scheduled weekly inspection if the structure has changed or may have been damaged. The competent inspector should review the corrected structure against the current design and intended task, checking access, working platforms, guard rails, toe boards, ties, bracing, foundations, loading bays, sheeting and any special components relevant to the alteration.

The inspection report should identify the scaffold and affected section, date and time, inspector, condition, defects, corrective actions and any restriction. A tag can make status visible, but HSE says a tag system is not itself a legal requirement or a substitute for the inspection record. Separate physical acceptance from work permission: the scaffold may be structurally suitable again but not for a newly proposed heavy load or hoist, so write any load or use limit clearly and lift the exclusion only for the area and activity the competent inspection supports. If the condition is uncertain, keep the scaffold closed; a handover certificate dated before the change cannot release it, and a new electronic signature cannot make an incomplete physical correction safe.

Learn why the alteration happened

An unauthorised change can be a behaviour issue, a design-interface issue or both. Ask whether the scaffold obstructed planned work, whether the material route was realistic, whether the scaffold design was briefed to other trades, and whether anyone knew how to request a controlled alteration. Review coordination between the principal contractor and scaffold contractor: was there a named alteration-request route, did the scaffold contractor have capacity to respond, and were trades told which components must never be moved and which planned changes require a redesign? Walk other areas for similar informal changes, since a removed tie may be one of several, and test the correction on the next similar task: if materials still cannot pass without touching structural or fall-protection components, the work plan needs redesign.

Consider reporting duties if the alteration caused injury, collapse or another specified event, but do not assume every missing component is automatically reportable under RIDDOR; preserve the internal incident record and obtain competent reporting advice against the facts. Immediate exclusion and safe correction should not wait for the statutory reporting decision.

Where Complys can help

Complys publicly describes a scaffold handover certificate workflow and Projects records that keep project documents and work reports together, which can hold the original handover, the change report, the correction and the new inspection in one trail. Complys does not detect a moved tie, assess scaffold design, perform a statutory inspection or certify return to use automatically: a digital certificate records a competent person's conclusion only where that person actually inspected and was authorised to make it. Keep design, inspection and return-to-use decisions with competent scaffold personnel and ask the Complys team to demonstrate the current certificate and Projects workflow if your team needs a traceable handover history.

Related scenarios: a temporary prop moved from its approved position.