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Does Your Temporary Works Designer Have Enough Information to Design Safely?

Does Your Temporary Works Designer Have Enough Information to Design Safely?

Temporary works design can only be as good as the information it receives. A drawing request that says little more than “design a working platform” or “provide excavation support” leaves important assumptions unresolved. Before design starts, the project needs to define the loads, geometry, sequence, interfaces, constraints and intended use clearly enough for a suitable solution to be developed.

The design problem needs defining before it can be solved

HSE’s temporary works guidance says temporary structures must be designed, installed and maintained to withstand foreseeable loads and used only for the purposes for which they were designed, installed and maintained.

That legal requirement sounds straightforward, but it depends on the design team knowing what those foreseeable loads and intended uses actually are. If plant type, imposed loads, sequence, ground information or interface with permanent works is missing, the designer may be forced to make assumptions that do not reflect what happens on site.

A useful temporary works brief therefore does more than request a drawing. It defines the engineering problem and records the information that the designer is entitled to rely upon.

Start with purpose, geometry and loading

The brief should explain what the temporary works are intended to achieve and for how long. Dimensions, levels, clearances, access requirements and interfaces should be clear enough for the designer to understand the physical problem.

Loads need the same discipline. For a working platform, that might include the actual plant, outrigger or track configuration, operational positions and any delivery vehicles. For propping, the designer needs to understand what is being supported, the sequence of load transfer and when the temporary support can safely be removed.

“Suitable for a crane” is not a design load. “Support the wall” is not a construction sequence. The information should be specific enough that the final design can be checked against the intended operation.

Ground and existing structures can control the design

Temporary works frequently depend on conditions outside the element being designed. Excavation support relies on ground conditions and surcharge. A loading platform may depend on the capacity of the supporting structure. A scaffold can impose loads on façades, slabs or foundations.

Known ground information, buried services, existing structural details and restrictions on where loads can be applied should therefore be supplied where relevant. If reliable information is unavailable, that uncertainty should be made explicit rather than silently replaced with an optimistic assumption.

This is particularly important when permanent works are being used temporarily during construction. The fact that a slab, wall or frame will eventually be strong enough does not automatically mean it can accept the proposed construction load at that stage of the sequence.

The construction sequence belongs in the conversation

HSE notes that a Temporary Works Coordinator may need to advise on build sequence, systems of work and equipment so other activities do not damage or compromise temporary works. Sequence can be central to the design, not simply a site-management issue after the drawing is issued.

Consider a propping arrangement designed on the assumption that load is transferred gradually through a particular sequence. If site operations remove props early, change pour order or introduce extra loading before the structure gains strength, the design may no longer represent the actual condition.

The brief should therefore capture significant erection, loading, alteration and dismantling stages where they influence stability or design.

Changes need to come back through the process

Temporary works often encounter change: plant is substituted, levels alter, access routes move, excavation depth increases or another contractor needs to use the system differently. The safe response is not to assume that a small site change has a small engineering effect.

The TWC should have a process for referring relevant changes back to the designer and obtaining revised or confirmed information before the temporary works are used outside the original design basis. HSE describes the TWC approach as an effective way of coordinating suitable designs, checking and correct erection.

It is important to distinguish this industry management approach from statute. HSE states there is no single specific legal requirement prescribing exactly how temporary works must be organised. The underlying legal duties concern safe design, installation, maintenance and use.

What should you do now?

  • Review the information your organisation normally sends with temporary works design requests.
  • State the intended purpose, geometry, duration and relevant construction stages.
  • Define real loads and plant configurations rather than generic descriptions.
  • Provide available ground, structural and service information where it affects the design.
  • Record significant assumptions and information gaps.
  • Define how site changes are referred back for design review.
  • Make sure the TWC has authority to stop use where the design basis has not been satisfied.

Our professional view

A temporary works register can tell you what designs exist, but it does not prove the designers were given the right problem to solve. A strong process starts earlier, with a brief that connects design calculations to the actual method, plant, sequence and site constraints.

For teams developing their understanding of the process, All Star Safety provides CITB Temporary Works General Awareness eLearning, while our consultancy service can assist with practical temporary works coordination and review.

Are You Overloading Floors During Construction?

Are You Overloading Floors During Construction?

Stacks of blocks, plasterboard, steel or plant can create loads a floor was not ready or designed to carry at that stage of construction. After a recent HSE prosecution involving a floor collapse, contractors should look again at how delivery locations, temporary loads, design information and structural stability are being controlled before materials arrive on site.

A £30,000 prosecution shows why temporary loading needs active control

On 18 August 2026, HSE reported the prosecution of an Oldham construction company after a 25-year-old bricklayer was seriously injured when the upper floor on which he was working collapsed.

The worker fell with a quantity of concrete blocks that had been stored on the floor. He suffered fractures to his leg, hip and hand, required surgery and remained in hospital for a month. HSE Media Centre

HSE found two particularly important issues. The floor had been overloaded with concrete blocks and had not been constructed in accordance with the manufacturer’s design. Inspectors also identified unsafe scaffolding, inadequate work-at-height arrangements, insufficient fire precautions and inadequate competent site management. HSE Media Centre

Oldham Business and Construction Management Limited pleaded guilty to breaching Regulation 13(1) of CDM 2015. The company was fined £30,000 and ordered to pay £4,883 in costs. HSE described the incident as part of a broader failure to plan, manage and monitor the construction work properly. HSE Media Centre

Read the HSE prosecution notice

Although the prosecution was brought under the principal contractor’s management duty, the circumstances also highlight a very specific legal requirement that deserves more attention: structures must not be loaded to the point that they become unsafe.

What does CDM 2015 actually require?

Regulation 19 of the Construction (Design and Management) Regulations 2015 deals directly with structural stability.

It requires all practicable steps to be taken, where necessary to prevent danger, to ensure that a new or existing structure does not collapse where construction work may make it unstable or leave it temporarily weak or unstable.

The Regulation then becomes particularly relevant to site loading. It states that temporary supports must be designed, installed and maintained to withstand foreseeable loads and that a structure must not be loaded so as to render it unsafe to any person. Legislation.gov.uk

Read Regulation 19 of CDM 2015

There is a wider management duty too. Principal contractors must plan, manage, monitor and coordinate the construction phase so that, so far as is reasonably practicable, construction work is carried out without risks to health and safety. HSE’s guidance specifically emphasises planning work stages and their sequence, not simply reacting once work has started. HSE

The legal requirement is therefore not merely to stop a worker putting “too many blocks” in one place. The project needs arrangements capable of identifying what can safely be loaded, where, when and under what conditions.

The finished floor capacity is not the whole story

One of the traps on site is assuming that because a floor will eventually carry a particular load, it can carry that same load throughout construction.

That may not be the case.

During construction, the structure can pass through several temporary states. Concrete may still be gaining strength. Temporary propping may be required. Bracing may not be complete. Connections may not have been fully installed, or elements that form part of the eventual load path may not yet exist.

There is also a difference between a relatively distributed load and placing several tonnes of material into a relatively small area.

A pallet of dense blocks, packs of plasterboard, steelwork, masonry, roofing materials or mechanical equipment can create a significant concentrated construction load. Moving several pallets to one convenient unloading point can alter the loading further.

The question for the site manager should therefore not be:

“What load will this floor eventually take?”

It should be:

“What can this floor safely carry at this stage, in this location and in its present condition?”

Where that cannot be answered from approved design information, manufacturers’ instructions or an agreed temporary works arrangement, the appropriate response is to obtain competent engineering advice rather than make an assumption.

HSE’s structural-stability guidance is clear that structures should never be overloaded and that where temporary support is necessary, its arrangement should be determined by suitably competent people and designed for the foreseeable loads involved. HSE

HSE guidance on structural stability

Where does temporary works management fit in?

Temporary loading is not always recognised as a temporary works issue because nothing obviously looks “temporary”.

There may be no scaffold, excavation support or falsework.

However, HSE includes permanent works being used temporarily during construction within its examples of temporary works. It also identifies propping to floors and walls, falsework, working platforms and other temporary structural arrangements as matters requiring proper planning and management. HSE

This can become important where a permanent floor is being asked to perform a temporary function — for example, supporting stored construction materials, plant or access equipment before the structure has reached its completed condition.

A Temporary Works Coordinator can provide an effective management route for identifying and controlling such issues. It is important, however, to distinguish good practice from a specific statutory appointment requirement.

CDM 2015 does not expressly require every project to appoint someone with the job title “Temporary Works Coordinator”. HSE says there are no specific legal requirements prescribing exactly how temporary works must be managed. It describes appointing a TWC as an effective method, and notes that BS 5975 provides a widely used management approach, particularly on medium and large projects. HSE

That distinction should not be taken as a reason to manage temporary works informally. Someone still needs sufficient authority and competence to coordinate designs, checks, loading restrictions, site conditions and changes.

On projects where temporary works form a significant part of the construction process, a properly implemented temporary works procedure and clearly appointed TWC are established industry good practice.

For supervisors and others who need a basic introduction to the subject, All Star Safety currently provides the CITB Temporary Works General Awareness course online free of charge. All Star Safety

Material storage needs planning before the delivery arrives

Material storage is often treated as a logistics or housekeeping problem. Structural loading shows why it also needs to form part of construction planning.

HSE advises that storage arrangements should be discussed and agreed between those involved in the project. It also recommends planning deliveries so that the amount of material held on site is kept to a sensible minimum. HSE

HSE guidance on construction material storage

That planning becomes particularly important when deliveries are being craned or telehandled directly onto upper levels.

Once a delivery vehicle arrives and a crane or telehandler is waiting, there can be considerable pressure to decide quickly where the materials should go. That is the wrong point in the process to start determining whether a floor can carry them.

Site logistics planning should establish the approved storage areas beforehand.

Depending on the project, that might involve confirming:

  • the permitted material and maximum quantity;
  • approved loading or lay-down areas;
  • any prohibited zones;
  • maximum loading stated by the designer or system supplier;
  • whether materials must be spread rather than concentrated;
  • whether temporary propping is required;
  • whether propping can be removed before materials are loaded;
  • restrictions during concrete curing or different construction stages;
  • how loading areas will be identified to delivery teams, crane operators and trades; and
  • who has authority to approve a change.

The final point matters particularly.

A well-controlled site can still become unsafe when somebody decides that the planned storage area is inconvenient and moves a delivery “just for today”.

Where a loading arrangement changes, the effect of that change should be considered before the materials are moved.

What should you do now?

Contractors and principal contractors should review how temporary construction loads are controlled rather than relying on general instructions to “spread materials out”.

Start by identifying floors, roofs, platforms and partially completed structures currently being used for materials storage or supporting plant. Check that the construction matches the approved design and that any required bracing, connections or temporary support are in place.

Then establish where the loading information comes from. If the designer, temporary works designer or system manufacturer has issued restrictions, make sure the site team can actually find and understand them.

Storage areas should be included in logistics arrangements and communicated to people controlling deliveries. Where useful, physically identify maximum loading areas or restricted zones rather than expecting every delivery team to interpret structural drawings.

Supervisors should also watch for gradual accumulation. Ten small deliveries over several days can produce the same structural problem as one large delivery if nobody is monitoring what remains stored on the floor.

Finally, if the site team cannot establish whether a proposed load is safe, stop and obtain competent advice. A delivery programme is easier to recover than a structural collapse.

Our professional view

Temporary loading is a good example of a risk that can sit between different parts of a project.

The structural designer may understand the floor capacity. The temporary works team may understand the construction sequence. The logistics manager controls deliveries. The subcontractor wants materials close to the workface. The site manager is trying to maintain the programme.

The danger appears when everybody assumes somebody else has considered how those pieces interact.

The HSE case published this week reinforces a basic principle: structural safety during construction must be actively managed in the temporary condition, not judged only by how the completed building is expected to perform. HSE Media Centre

For contractors needing project-specific help with temporary works, site controls or wider CDM arrangements, All Star Safety’s health and safety consultancy service includes project-based support, site audits and temporary works/complex civils assistance. All Star Safety