Engineering Law – Should an Engineer’s duties be extended beyond its contractual obligations?

The question of what the extent of an engineer’s duties are, usually come into play whenever an engineered structure fails.  One prominent element to this question is whether an engineer’s duties extend beyond a contractual obligation with its employer.    

In Strijdom Park Extension 6 (Pty) Ltd v Abcon (Pty) Ltd this issue was raised and clarified by the Supreme Court of Appeal.

In this matter the engineer was employed by Strijdom Park Extension 6 (Pty) Ltd (“the employer”) to design a steel reinforced concrete slab separating the ground floor from the basement of a warehouse which was erected by Abcon (Pty) Ltd (“the contractor”).  The concrete slab failed two years after occupation of the warehouse was taken.

The employer instituted a claim for damages against the contractor and the engineer, alleging that they had breached their respective agreements with the employer.  The claim against the engineer was settled, but the claim against the contractor was heard on appeal.  
The parties were in agreement that the collapse must have occurred during the casting of the slab when the concrete was poured over and into the network of the reinforcing steel.   
The question that had to be decided on appeal was, firstly, whether the failure of the slab was at least partly attributable to a defective engineering design and, secondly, whether the engineer had a duty to the contractor.  

The Court considered the following undisputed evidence:
•    the failure was due to the collapse of the upper of two criss-cross mats of steel bars that had been encased in the concrete to reinforce it;
•    the collapse was a consequence thereof that many of the stools (which kept the two mats apart) were found to have been bent out of shape;
•    the contact between the upper mat and the stools was limited to one bar of the mat resting on the centre of the horizontal piece of each of such stools;
•    the stools were not fastened; and
•    the stool collapse occurred during the casting of the slab.

The contractor, firstly, took the stance that it was not liable for the damages as it had constructed the concrete slab in accordance with the engineer’s design, which was allegedly defective.

Secondly, the contractor relied on the fact that the engineer had approved the way in which the reinforcement was installed.  

Lastly, the contractor pointed out that the engineer’s design did not indicate that there had to be two bars of the top mat per stool, nor that the stools had to be fastened.

The contractor claimed that it did not notice the collapse of the upper mat, nor did it realise that the stools had not been tied.  It is clear from the contractor’s evidence that he left every relevant decision pertaining to the assembly of the reinforcement to the engineer and the steel contractor.  

The employer contended that:
•    It was the duty of the contractor to assemble the reinforcement mats and to maintain same in the correct position.

•    Proper construction practice demanded that, wherever possible, two bars of the upper mat should be placed on each stool and that the feet of the stools be tied.  There is no reason for an engineer to indicate these practices on his drawings as these requirements are part and parcel of proper construction practice and solely the contractor’s duty.

•    The contractor should have noticed the collapse during the pouring process and should have stopped the work in order to consult the engineer.

•    If the contractor had observed its duties as set out above, the failure would not have occurred.

The Court agreed with the employer’s stance.  

There was no evidence supporting the allegation that the engineer’s design was defective.
Although the engineer had approved the steel structure on site, he did not carry a duty to supervise the work of the contractor.  It was the contractor’s decision how it carried out the construction work and it cannot shift the blame to the engineer in the circumstance where it did not perform its work in a proper and workmanlike manner.  It was also the contractor’s obligation to ensure that the construction of a design is free of defects.

In the Court’s view, it was reasonable of the engineer to expect that the contractor would ensure proper assembly of the reinforcement mat by noticing any displacement and taking appropriate action if it occurred.  

The Court further clarified that the engineer had only a contractual duty to its client and not to the contractor.  The engineer did not even have a duty to intervene if the contractor appeared to be going wrong (unless it was apparent to the engineer that the contractor did not know his business and was going to go wrong).  Such a duty to intervene would only arise if the contractor appeared set on an incredible act of recklessness.  

The Court therefore held that the slab had failed because the contractor failed to carry out the construction in a proper and workmanlike manner.

•    An engineer’s duties are not extended beyond what is set out in his agreement with his employer.  

•    An engineer will therefore not have the duty to supervise the work of a contractor, unless he is contractually required to do so and he cannot be held liable for another party’s contractual breach.