Many civil engineering contractors now use sub-contractors to do much of their work. Most conditions of contract permit a contractor to sub-let work of a specialist nature; but the ICE conditions of contract have gone further and permit the contractor to sub-contract any part of the work (but not the whole of the work), subject only to notifying the engineer of the work sub-contracted and the name of the sub-contractor appointed to undertake it.
The contractor does not have to notify any labour-only sub-contracts he uses.
The engineer can object, with reasons, to the appointment of a sub-contractor, but otherwise has no rights in connection with such sub-contracts, except that he can require removal of a sub-contractor who proves incompetent or negligent, or does not conform to safety requirements. Under FIDIC conditions for overseas work, sub-contracting requires the engineers prior sanction.
In building work there has long been a trend to pass the majority of work to sub-contractors who specialize in various trades, and the same has now occurred in civil engineering where many operations are packaged up and sub-let. Thus sub-contracts may be let for excavation, formwork, reinforcement supplied and erected, and concreting. The advantage to the contractor is that this reduces the staff he needs on site and his capital outlay on plant and equipment. He can use sub-contractors with proven experience and does not have to take on a range of temporary labour whose quality may be variable.
The contractor retains responsibility for the quality and correctness of work and, of course, has to plan and co-ordinate the sub-contract inputs, and often supply any necessary materials.
But if much of the work is sub-contracted, the contractors or agents main input to a project may be that of dealing with the sub-contracts and controlling their financial outcome, so these matters may take priority over dealing with any engineering problems which arise. The contractor may therefore tend to leave a sub-contractor to solve any problems he encounters, on the basis that these are his risks under his sub-contract and it is up to him to deal with them.
But the sub-contractor may think otherwise, so a dispute arises as each considers the other responsible for any extra cost or delays caused.
Frequent disputes have also arisen in recent years when any default or presumed default by a sub-contractor has resulted in the contractor withholding payment to him. Late payment by contractors to sub-contractors is another widespread source of complaint by sub-contractors, but remedies are difficult to devise. The sub-contracts are private contracts whose terms are unknown to the engineer and the employer, so they cannot interfere in any such dispute.
The engineer has only power to protect nominated sub-contractors, i.e. subcontractors he directs the contractor to use (see Section 15.8).