Mace’s deadline to build the Shard has come under renewed pressure after a key part of the 310m tall tower has had to be repaired
Building understands steelwork contractor Severfield-Rowen is carrying out remedial work to steel fabricated by Cleveland Bridge UK for the £350m Renzo
Mace replaced CBUK with Severfield last year, before work on site had started, but part of the revised deal involved CBUK fabricating steel for the bottom nine floors.
Problems with the weldings and dimensions are being blamed and repairs are expected to take about a month, although there is no indication that the overall deadline of May 2012 for western Europe’s tallest building will slip.
A CBUK source said the repairs would take up to four weeks, and that they were necessary because of changes to the drawings.
He added: “There is the odd fabrication error. Extra bits were added to the drawings after fabrication. Some holes don’t line up and some brackets are welded in the wrong areas.”
A Severfield source admitted the work it had to carry out would slow down progress. “The problem is that we’re having to work behind ourselves as well as ahead. We’re doing it ourselves as we’ve got loads of resource.”
A Mace spokesperson said: “There have been some very minor tolerance issues which have now been completely resolved and we anticipate completion of this element of the programme on schedule in late 2010. There is no impact on the wider programme.”
The hitch follows a delay to the start of the scheme when there was a switch from construction management to a fixed-price contract. To get the project back on track, Mace “jump-started” the core construction - a technique that enables the concrete core and steel superstructure to be built upwards while the core is still being built downwards into the basement.
This has the potential to shave three months off the construction time.