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What are temporary works? |
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FAQ
What Is Considered Temporary Works in Construction?
If temporary works are poorly planned, installed without proper checks, altered without approval, overloaded or removed too early, the consequences can be immediate. Temporary works therefore need to be identified early, designed where necessary, checked to the correct category, installed in accordance with the design, inspected before use, monitored where required and removed in a controlled sequence. Mihai Chelmus, Founder and Editor of London Construction Magazine and a construction testing and investigation specialist, has worked around temporary works installation, structural investigations, load testing, anchor testing, propping arrangements, inspection regimes and site compliance evidence across UK construction projects. In practice, the risk is often not the temporary works item itself, but the gap between what the design assumes and what is actually installed, loaded or altered on site.
What Counts as Temporary Works?
A temporary works item can be structural, geotechnical, access-related, protective or construction-method related. It may be designed by a temporary works engineer, supplied as a proprietary system, installed by a subcontractor or assembled from project-specific materials such as steel beams, props, scaffold tubes, hydraulic jacks, concrete blocks, timber, anchors, kentledge or spreader beams. The table below sets out common categories of temporary works found on UK construction projects.
Common Examples of Temporary Works
Common examples of temporary works include scaffolding, temporary edge protection, formwork, falsework, trench boxes, excavation support, propping, shoring, façade retention, loading platforms, tower crane bases, piling platforms, crane mats, temporary bridges, crash decks, temporary access stairs, site hoarding and temporary stability bracing.
| Temporary works category | Typical examples | Why it matters |
|---|---|---|
| Support and propping | Acrow props, RMD soldiers, steel needles, back-propping, temporary beams, hydraulic jacks | Used to support existing or partially complete structures during alteration, demolition, repair, testing or temporary loading. |
| Excavation support | Trench boxes, sheet piles, shoring frames, walers, struts, battered excavations | Controls ground collapse risk and helps protect workers, adjacent structures, services and public interfaces. |
| Formwork and falsework | Concrete formwork, soffit support, falsework towers, temporary decks, shuttering systems | Supports wet concrete, reinforcement, construction loads and temporary construction stages until the permanent element can support itself. |
| Access and working platforms | Scaffolds, mobile towers, gantries, temporary stairs, crane platforms, piling platforms | Provides safe access or plant support before the permanent structure or permanent access route is available. |
| Temporary stability systems | Façade retention, temporary bracing, restraint ties, stability frames, temporary fixings | Prevents movement, collapse or instability during demolition, refurbishment, sequencing or structural alteration. |
| Protection and segregation | Hoarding, edge protection, fans, crash decks, temporary barriers, exclusion systems | Protects workers, the public, live buildings, adjacent property and site interfaces from construction risk. |
| Testing and reaction arrangements | Load test frames, hydraulic jack reaction systems, kentledge, water bags, test anchors, spreader beams | Introduces temporary loads or reaction forces into structures that may need engineering review, inspection and controlled sequencing. |
In refurbishment and structural investigation work, temporary works can also include temporary support to existing slabs, beams or walls while openings are formed or intrusive inspections are undertaken. This may involve props, steel needles, hydraulic jacks, spreader beams, temporary bearing plates, restraint systems or controlled load-transfer arrangements.
On demolition and alteration projects, temporary works may be required before the main works can safely proceed. Examples include façade retention to keep an external wall stable while internal floors are removed, back-propping to existing slabs where heavy plant is introduced, temporary bracing to steelwork, or temporary support while openings are cut through walls, floors or beams.
The Five-Question Test: Is It Temporary Works?
A practical way to identify temporary works is to ask five site-level questions.
1. Does it support something?
If it supports a structure, excavation, load, formwork, platform, access system or plant item, it is likely to fall within temporary works control.
2. Does it restrain or stabilise something?
If it prevents movement, collapse, overturning, sliding, settlement or lateral instability during construction, it should be treated as temporary works.
3. Does it provide access or a working platform?
If it allows workers, plant, materials or equipment to access an area safely before the permanent access is available, it may be temporary works.
4. Does it protect workers, the public or the structure?
Hoarding, fans, crash decks, exclusion systems, temporary screens and barriers may all require temporary works consideration depending on risk, exposure and loading.
5. Does it introduce temporary load into the structure?
Temporary loading from plant, kentledge, water bags, hydraulic jacks, test rigs, stored materials, demolition sequencing or construction operations can require temporary works assessment.
Testing, Inspection and Temporary Works: The Overlooked Interface
One area often missed in generic temporary works guidance is the interface between testing, inspection and temporary loading. Structural testing and investigation work can create temporary load paths, temporary openings, reaction forces or access requirements that need to be considered before site work starts. For example, a controlled load test using water bags, kentledge, hydraulic jacks or reaction frames may temporarily load a slab, beam, ceiling panel, anchor group or supporting structure. The test equipment may only be on site for a short period, but the forces introduced can still be significant.
The same applies to temporary propping during breakouts, core drilling, reinforcement exposure, façade restraint, anchor testing or slab investigation. If the testing arrangement changes load paths, provides reaction, restrains movement or places temporary force into a structure, it should be reviewed through the temporary works process. This is where practitioner experience matters. A drawing may show a theoretical arrangement, but the site condition may involve unknown reinforcement, uneven bearing, cracked concrete, limited access, variable slab thickness, existing services, incomplete records or unclear load paths. Inspection and testing evidence help close the gap between design assumption and site reality.
Temporary Works Are Not Just Products
Temporary works are not always proprietary systems supplied by a specialist manufacturer. A temporary works arrangement can be formed from ordinary site materials when those materials are used to support, restrain, protect, access or temporarily load part of the works. A steel beam, timber packer, concrete block, hydraulic jack, tie rod, scaffold tube, plywood deck, resin-fixed anchor or spreader plate can all become part of temporary works depending on how they are used. The important question is not what the item is called, but what function it performs on site. This is where many errors occur. A contractor may see an arrangement as “just a few props” or “only a short-term support”, while the actual structural behaviour depends on load path, bearing, eccentricity, restraint, deflection, installation quality, sequence and removal method.
Temporary Works and BS 5975
In the UK, temporary works are commonly managed using the BS 5975 framework. The current standards landscape has moved from a single broad document to a split structure, with BS 5975-1:2024 covering management procedures for the control of temporary works and BS 5975-2:2024 covering falsework design and implementation.
If it supports a structure, excavation, load, formwork, platform, access system or plant item, it is likely to fall within temporary works control.
If it prevents movement, collapse, overturning, sliding, settlement or lateral instability during construction, it should be treated as temporary works.
If it allows workers, plant, materials or equipment to access an area safely before the permanent access is available, it may be temporary works.
Hoarding, fans, crash decks, exclusion systems, temporary screens and barriers may all require temporary works consideration depending on risk, exposure and loading.
Temporary loading from plant, kentledge, water bags, hydraulic jacks, test rigs, stored materials, demolition sequencing or construction operations can require temporary works assessment.
The management side is important because temporary works failures are rarely caused by calculation alone. They often arise from poor communication, incomplete design briefs, unclear responsibilities, unapproved changes, missing checks, incorrect installation, lack of inspection, premature loading or uncontrolled removal.
A strong temporary works process should include identification, design brief, appointment of competent persons, design, design check, permit or approval to load/use, inspection, monitoring where required, change control and controlled dismantling.
Who Decides Whether Something Is Temporary Works?
The decision should not be left to guesswork by the operative installing the item. On properly controlled projects, temporary works are normally identified through the contractor’s temporary works procedure, risk review, construction methodology, design brief process, RAMS review, design coordination and site supervision arrangements.
Depending on the project, the people involved may include the client, principal designer, principal contractor, temporary works coordinator, temporary works supervisor, temporary works designer, design checker, site manager, subcontractor, structural engineer, temporary works engineer and specialist testing or installation contractor.
The practical rule is simple: if the arrangement could affect structural stability, ground stability, access safety, public protection, plant support, load transfer or construction sequencing, it should be raised early and assessed properly.
Temporary Works Under CDM
Temporary works sit inside the wider legal framework for managing construction risk. CDM 2015 applies to construction work and places duties on clients, designers, principal designers, principal contractors, contractors and workers. Temporary works are not managed in isolation from CDM. They are part of how design risk, construction risk, sequencing risk and site coordination are controlled.
Where temporary works are needed, the project team should make sure that the temporary condition is considered as carefully as the permanent design. This includes whether the temporary works are required, who designs them, who checks them, who installs them, who inspects them, who authorises loading or use and who controls alteration or removal.
Common Mistakes When Identifying Temporary Works
The first mistake is assuming that only scaffolding and formwork count as temporary works. In reality, temporary works can include a much wider range of supports, platforms, anchors, access systems, protection systems and site-specific arrangements.
The second mistake is treating temporary works as low risk because they are short duration. A support used for two hours can still be critical if it carries a live structural load, restrains an unstable element or protects people from collapse.
The third mistake is altering temporary works on site without design approval. Moving a prop, removing a brace, changing a bearing plate, adding extra load or modifying a sequence can invalidate the assumptions behind the design.
The fourth mistake is failing to include testing and inspection arrangements in the temporary works review. Load testing, anchor testing, slab testing, water bag loading, hydraulic jacking and reaction systems can all introduce temporary forces that need to be understood.
The fifth mistake is poor record keeping. A temporary works register, design brief, check certificate, inspection record, permit to load or permit to strike can become essential evidence if the project later needs to prove that risks were identified and controlled.
Evidence-Based Summary
Temporary works risk is not driven by a single factor but by a combination of temporary loading, structural support, access requirements, sequencing, design assumptions, installation quality and change control. While many people associate temporary works only with scaffolding or formwork, site evidence shows that propping, shoring, hoarding, excavation support, working platforms, test reactions and temporary stability systems can be equally important. In practical terms, anything that supports, restrains, protects, accesses, stabilises or temporarily loads a structure during construction should be reviewed through the temporary works process.
FAQ: What Is Considered Temporary Works?
What is considered temporary works in construction?
Temporary works include temporary structures, supports, access systems, excavation support, formwork, falsework, propping, shoring, hoarding, temporary platforms, crane bases, piling platforms, restraint systems and temporary stability measures needed to allow permanent works to be constructed safely.
Is scaffolding temporary works?
Yes. Scaffolding is a common form of temporary works because it provides temporary access, support or protection during construction, maintenance, refurbishment or demolition.
Is hoarding temporary works?
Hoarding can be temporary works where it acts as a temporary structure used for site protection, public segregation, wind loading resistance, security or interface control.
Is a trench box temporary works?
Yes. A trench box is temporary works because it provides temporary excavation support and helps protect workers from ground collapse during excavation works.
Are crane platforms and piling platforms temporary works?
Yes. Crane platforms and piling platforms are normally considered temporary works because they support plant and temporary construction operations. Some may later be incorporated into the permanent works.
Can testing equipment create temporary works?
Yes. Testing equipment such as hydraulic jacks, kentledge, reaction frames, spreader beams, water bags and test anchors can create temporary load paths or reaction forces. These arrangements should be reviewed where they affect structural stability or site safety.
Does every temporary works item need a full design?
Not every temporary arrangement requires the same level of design, but every temporary works item should be identified, assessed and controlled in proportion to its risk. Higher-risk or structural temporary works will normally require a design and appropriate design check.
Who is responsible for temporary works?
Responsibility depends on the project structure, but temporary works normally involve the principal contractor, contractors, temporary works coordinator, temporary works supervisor, temporary works designer, design checker and those installing, inspecting and using the works.
Temporary works include temporary structures, supports, access systems, excavation support, formwork, falsework, propping, shoring, hoarding, temporary platforms, crane bases, piling platforms, restraint systems and temporary stability measures needed to allow permanent works to be constructed safely.
Yes. Scaffolding is a common form of temporary works because it provides temporary access, support or protection during construction, maintenance, refurbishment or demolition.
Hoarding can be temporary works where it acts as a temporary structure used for site protection, public segregation, wind loading resistance, security or interface control.
Yes. A trench box is temporary works because it provides temporary excavation support and helps protect workers from ground collapse during excavation works.
Yes. Crane platforms and piling platforms are normally considered temporary works because they support plant and temporary construction operations. Some may later be incorporated into the permanent works.
Yes. Testing equipment such as hydraulic jacks, kentledge, reaction frames, spreader beams, water bags and test anchors can create temporary load paths or reaction forces. These arrangements should be reviewed where they affect structural stability or site safety.
Not every temporary arrangement requires the same level of design, but every temporary works item should be identified, assessed and controlled in proportion to its risk. Higher-risk or structural temporary works will normally require a design and appropriate design check.
Responsibility depends on the project structure, but temporary works normally involve the principal contractor, contractors, temporary works coordinator, temporary works supervisor, temporary works designer, design checker and those installing, inspecting and using the works.
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Expert Verification & Authorship: Mihai Chelmus
Founder, London Construction Magazine | Construction Testing & Investigation Specialist |
