Do steel erection contractors supply the steel frame as well as erect it?

Steel erection contractors may supply the steel frame as well as erect it, but this is a contractual option rather than an automatic part of every erection service. A contractor may provide a complete supply-and-erect package, or install a frame that has been designed and purchased from another supplier. The quotation and contract should make clear which arrangement applies.

Under a supply-and-erect package, one contractor generally coordinates the stages that connect the design to the completed frame:

• reviewing the building requirements, site information and intended use;
• developing or checking the structural design and fabrication drawings;
• manufacturing the frame to the agreed specification;
• arranging delivery of the steelwork to site;
• assembling and securing the frame in the planned sequence; and
• confirming what documentation is provided at completion.

This route gives the client one principal steelwork package to coordinate. It can reduce the risk of a mismatch between the members manufactured and the method used to erect them, because the design, fabrication and installation requirements are considered together. It also makes it easier to establish who is responsible for resolving an issue if a connection, opening or member does not correspond with the approved drawings.

A separate-frame arrangement works differently. The steel manufacturer or client supplies the members, while the erection contractor is appointed to unload, assemble and install them. Before accepting that work, the erector should check the frame drawings, member schedule, connection details and delivery information. The contractor also needs to understand what equipment, temporary bracing and access will be required. If the frame arrives incomplete, incorrectly marked or without essential connection components, responsibility may depend on the wording of the contract rather than on who is physically carrying out the erection.

Supplying the steel frame does not automatically mean that the contractor supplies every part of the building. Items such as foundations, groundworks, floor slabs, cladding, roofing, doors, drainage, insulation, electrical systems and internal fit-out may be separate packages. Some projects also require the client or another contractor to provide lifting equipment, site access, welfare facilities or prepared working areas. These exclusions should be identified before the price is accepted.

The design responsibility should be treated with particular care. A contractor may prepare fabrication information from an agreed structural design, or may provide a wider design service that includes the structural scheme and drawings needed for planning and manufacture. Those are not necessarily the same obligation. The agreement should state who is responsible for structural calculations, design checks, connection design, alterations requested after approval and compliance with the project specification.

When comparing supply-and-erect quotations, check whether they include:

• the steel grade, protective treatment and member sizes;
• base plates, bolts, cleats, bracing, connection components and other loose steelwork;
• design drawings, fabrication drawings and any required calculations;
• delivery, unloading and the sequence in which materials will arrive;
• craneage, access equipment, temporary works and installation labour;
• site tolerances and the condition required of foundations before installation;
• work associated with cladding or other trades, if it is included; and
• handover information, inspection records and the treatment of variations.

For an agricultural, industrial or equestrian building, the intended use can affect the frame specification. Clear internal spans, storage loads, machinery movements, openings, roof-mounted equipment and future expansion should be discussed before the frame is finalised. Changing these requirements after fabrication can affect both the steelwork and the erection sequence.

Buildings UK Ltd provides a choice between purchasing a steel building kit and appointing a full erection service. The appropriate option depends on the client’s construction capability, available site management and preference for coordinating separate trades. Whichever route is selected, the essential point is to obtain a written scope that separates the supplied steelwork from the installation work and clearly allocates every related responsibility.