Even when a main contractor or subcontractor is acting on the instructions of engineers it must warn of any problems with temporary work that may lead to a failure - especially if a contract does not state which party is responsible for design, writes Lindy Patterson
THE ISSUE of who is responsible for the design and adequacy of temporary work on site is always a source of contention between contractors and engineers.
Who is to blame if, during construction work, you find yourself with a collapse on site? More importantly who is going to pay for the consequences?
By temporary work we generally mean the temporary support of any part of the work during construction.
This can range from commonplace tasks, such as shoring up excavations or building temporary access roads, to something as complex as the temporary supporting structure for a bridge during its construction.
To check who is responsible for the adequacy of these temporary measures the obvious place to start is the contract.Many contracts specifically place responsibility on the contractor; the ICE 6th Edition, for example, provides that the contractor shall take full responsibility for the adequacy, stability and safety of all site operations and methods of construction.
Sometimes the contract says nothing about who is responsible for temporary work. But, because the contractor has the right to carry out its own operations in whatever manner it thinks fit, it is generally assumed that it must also take responsibility for the design and construction of temporary work.
But what if the engineer imposes specific requirements on the contractor's methods of working, which, in turn, affect the design of the temporary work? And what happens when the contractual set-up gets more complicated? Should the contractor still be held responsible in these circumstances?
In a recent case (Plant Construction v Clive Adams Associates) the subcontractor, Plant Construction, denied responsibility for the collapse of a temporary support structure during construction of a roof.
The terms of the subcontract had been altered to require Plant to comply with the engineer's instructions and it was the engineer that had determined the positioning of the supporting props.
Thus the design responsibility was taken out of the subcontractor's hands and Plant escaped liability - or so it thought.
In fact the subcontractor was found to be in breach of an implied term of the contract to warn the contractor of the inadequacy of the temporary work.This decision was irrespective of any instruction issued by the employer's engineer on the project.
This implication was considered to be part of Plant's duty to take reasonable skill and care.
In fact Plant Construction, realising that there were problems with the method of temporary work suggested by the employer's engineer actually did warn the contractor.But it was still found to be in breach.
Why? Because it hadn't protested vigorously enough.
The case upheld the principle that, in the absence of any contractual provision to the contrary, a subcontractor is responsible for the design of temporary work that is part of its contract.
Nevertheless, even when the design responsibility remains with the contractor it does not necessarily relieve others who might have contributed to the problem.
For example, most contracts require the contractor to give the engineer general details of any temporary work, together with its methods of construction, in advance.
The engineer may propose significant changes, perhaps to satisfy itself that the temporary work or methods of working will not adversely affect the permanent work. ICE 6th Edition, for example, specifically states this is the engineer's role. In this situation the contractor does not necessarily bear sole legal responsibility.
This was demonstrated in another recent case, Arum Investments v Avonforce and others.
Here a subcontractor was engaged by the main contractor to do underpinning in order to protect the flank wall of the neighbouring property.
After the underpinning was completed the contractor began to excavate a basement and garage alongside the neighbouring property without providing any temporary support for the flank wall or the concrete bases installed by the subcontractor.
The central section of the excavation alongside the flank wall collapsed.
The contractor, having already received a contribution from its engineer, tried to sue its subcontractor for part of the sums it had paid as damages to the client.
The contractor argued that the subcontractor should have warned of the need to provide lateral support.
But the court decided that the subcontractor was not liable for the collapse.
The subcontractor did not know how the contractor would carry out the work it was to undertake, nor was there any reason for the subcontractor to suppose that the contractor would carry out its work negligently.
Furthermore, the subcontractor knew that the contractor had the advice of a structural engineer.
It would have been unreasonable, in these circumstances, to expect the subcontractor to warn the contractor of the need for lateral support.
But if, on the other hand, the subcontractor had been aware of the contractor's proposals and had said nothing, it might well have found itself liable for a contribution.
The problem does not end with temporary work; the inter-relationship of the temporary work with the final work means they can seldom be looked at in isolation.
For example, temporary work can sometimes become incorporated within the permanent work, often at the suggestion of the contractor, during the course of a project.
The engineer does bear liability in such situations - even though the ideas may be initiated by the contractor by reason of speed or economy.
As the engineer is responsible for the design of the permanent work and the temporary work is to become permanent, it is considered he must be satisfied that they are adequate for incorporation.