What is Temporary Works in Construction?

The defining characteristic of temporary works is that they carry loads that the permanent structure will never see in its service life. A falsework system supporting a bridge deck during a concrete pour may carry the full wet weight of the concrete plus construction equipment — a combination far exceeding the traffic loads the finished bridge is designed for. A strand jack frame carries the full weight of a roof structure being lifted in a configuration that the permanent roof, once in place, will never replicate.

This is why temporary works design is a specialist discipline and, in many jurisdictions, a legally separate design obligation from the permanent works.

Falsework supports formwork during concrete pours. It must carry the weight of wet concrete, formwork, construction equipment and live loads from workers, and transfer these loads to the ground or the permanent structure below.

Launching gantries are the primary erection equipment for precast segmental bridges, spanning between piers to lift and place segments in balanced cantilever or span-by-span configurations.

Temporary bracing and propping provides stability to structures during erection before permanent connections are made. On steel framed buildings, temporary bracing holds the frame plumb while columns are being bolted and welded. On offshore jacket installations, temporary bracings maintain geometry during load-out and upending.

Marine temporary works include mooring systems for positioning vessels and barges, temporary buoyancy aids for floating structures, and grillage systems for load-out operations.

Temporary works failures are disproportionately represented in major construction collapses. The Loddon Viaduct falsework collapse in 1972 is a recognised example of the consequences when temporary works loads are underestimated. It directly influenced the development of UK temporary works practice, leading to BS 5975-1:2024 (management procedures) and BS 5975-2:2024 (falsework design) — the codes that govern temporary works design and management today.

The approval chain for temporary works designs — contractor, designer, client checker, independent verifier — is a principal source of sequence delay on major projects. Each link in that chain adds days to the critical path. And on projects where erection plant is mobilised at day-rate, those days have a known and specific cost that the approval chain rarely sees.

Temporary works decisions are rarely made in isolation from the erection method itself. The choice of launching gantry, strand jack frame, or falsework system is as much an erection-strategy decision as it is a temporary works design exercise — the two are typically settled together, early, because the temporary works scheme frequently determines what erection sequence is even possible.

This is why erection strategy planning treats temporary works as a design input rather than a downstream deliverable. A sequence that looks efficient on paper can be unbuildable once the required falsework, bracing, or lifting frame is priced and programmed — and the reverse is also true: a temporary works scheme chosen without reference to the erection sequence can lock in delay or cost that better coordination would have avoided.

The commercial exposure described above — approval-chain delay, day-rate plant sitting idle — is usually the visible symptom of temporary works and erection strategy having been planned separately rather than as one decision.