however advised the contractor that there was no mention of tanking in either the tender documents or in the drawings and insisted at that stage on the strict adherence to the design and specifications on which the tender was based. Tow leak
the end of 1977, before the completion of the contract, slight leakage occurred but the seriousness of the problem was not really apparent until the middle of 1978, after the contract had been completed, when the water table rose sharply during heavy rain.
138. In March 1979 an investigation into the failure of the waterproofing of the basement was completed by the Architectural Services Department. The investigation report concurred with the consultants' opinion that the failure of the waterproofing was caused by poor concrete work, in particular by poorly erected and braced shuttering, insufficient compaction and a lack of care in placing concrete.
139. In commenting on the design and construction works the investigation report noted that the design of the basement relied completely on waterproofed concrete for waterproofing. While the report concluded that such a design was an acceptable alternative to the conventional tanking by rock asphalt and an approach which could be considered as correct in principle, the quality of the concrete work was important. Stringent specifications had therefore been incorporated into the contract specifications by the consultants who insisted upon a continuous pouring of concrete for the entire height of the perimeter walls. The report noted however that whilst this could be achieved in theory it was very difficult in practice. In the event the contractor employed a different but unsatisfactory method and as he was allowed to proceed without question the report stated that the acceptance of the unsatisfactory method must be the responsibility of the consultants. The report acknowledged that the contractor had difficulties and that despite his repeated requests for guidance he had had to proceed without directions. Whilst it appeared that he was responsible for the failure of the waterproofing in the basement, there were mitigating factors.
140. With regard to the supervisory arrangements on site, the investigation report did not accept the consultants' claim that the normal degree of supervision by them was not necessary as the project had full-time supervision by the Government site staff. With regard to the liaison between the Architectural Services Department and the consultants, the investigation report noted that procedures were laid down in the instructions to the consultants to ensure that the project was processed in accordance with the Government procedures, but questioned whether the same degree of scrutiny of the consultants' work was carried out by the Architectural Services Department staff as for those projects carried out in-house. The report however stated that the inclusion of the basement in the design at a location where a high water table was expected and the method of waterproofing adopted must be construed as having had the approval of the Architectural Services Department as an architect and a structural engineer from the department were liaison officers to the project from its inception.
141. To improve the procedures and avoid a similar recurrence the investigation report recommended that in future where the introduction of a basement into a design was proposed, the method of waterproofing and its execution should be the subject of careful scrutiny at an appropriate level and that strict guidelines in the form of an office instruction should be issued. The report raised the point that it might be necessary to impress upon liaison officers that projects under the control of consultants should in all respects be processed in exactly the same way as those done in-house. Technical instructions covering these points were subsequently issued in 1979 and 1980.
142. When considering what remedial works were necessary the investigation report said that there could be no 100% cure, unless the structure was taken down and completely rebuilt, which was considered out of the question, and stated that the logical solution was to be as practical and economical as possible. The report therefore accepted the consultants' recommendation of the use of a liquid waterproofing solution which carried with it a guarantee of ten years by the specialist contractor and cost $150,300. The report further recommended that negotiations be conducted with the substructure contractor to recover as much of the cost of the remedial works as possible and that the actual works be undertaken by the superstructure contractor who was then on site. No recommendation was made about action to be taken against the consultants and legal advice was not sought.
143. The investigation report's recommendations were accepted by the Architectural Services Department and, notwithstanding that reservations were expressed about the effectiveness of the proposed waterproofing material by the Materials and Library Committee of the Architectural Services Department and by the superstructure contractor, its use was ordered. The remedial works were completed in July 1980 and whilst the actual cost of the waterproofing treatment was $233,000 (a sum of $90,000 was agreed with and recovered from the substructure contractor), the total cost of the remedial works carried out at this stage, including claims from the superstructure contractor for delays and disruption to his programme, was $0.8 million. The waterproofing subsequently proved to be ineffective but no action was taken against the specialist contractor as it was considered that his limited guarantee was not demonstrably breached. In 1984 further remedial works aimed at collecting the water seepage through the walls and floors of the basement rather than stopping the seepage of water also failed to resolve the problem, resulting in the latest proposals to provide an internal waterproof tanking system.
144. In response to my enquiries, the Director of Architectural Services informed me that the stadium was constructed under a tight budget and timescale and that if sheet piling and asphalt tanking had been adopted at the outset the cost of constructing the basement would almost certainly have doubled, the length of contract extended and the size of the basement reduced. The Director also informed me that the dry site conditions prevailing before and during the contract must have had an influence on any judgement exercised by the professionals concerned and the design and method of construction were therefore dictated by site limitations, site conditions and time. He stated that subsequent development
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