Inadequate foundation reinforcement

Subcontractors carrying out the ground works for a multi-storey development failed to provide sufficient continuity reinforcement in the ground beams. In an attempt to provide continuity, the steelwork was repositioned with the result that all reinforcement from a corner of the building was removed (highlighted in Figure 1). The local authority building control officer twice advised the sub contractors that this was unsatisfactory, but they claimed that the consulting engineer had considered the work acceptable. Regardless of this statement the work was not approved.

The reporter advises that this is not an isolated case because on many sites there is little or no involvement of the design engineer to ensure that his details are being followed on site. Traditional checks on construction standards from clerk of works and site resident engineers are now rare because clerk of works are not generally employed and the site engineers knowledge usually relates to setting out only.

A reputable design team and main contractor were carrying out this development but the lack of basic knowledge of the ground workers would have gone unchecked if it had not been for the local authority inspection. There is, considers the reporter, a concern about the lack of site involvement by design engineers in respect of critical areas of construction. Reliance is placed on sub contractors but their lack of knowledge creates risk of fundamental errors in the construction process.