Cladding work on the 800 m-plus Burj Dubai has yet to start and the delay could mean the iconic tower misses its planned 2008 completion.

Having reached 87 storeys the Besix, Arabtec Samsung joint venture (JV) has yet to start cladding work. The exposed concrete core now stands at 300 m.

Difficulties in sourcing the cladding following Switzerland-based Schmidlin’s collapse in February were originally being blamed for the lack of progress.

Schmidlin LLC UAE, which is a locally owned company, is continuing to supply the project in a joint venture with Arabian Aluminium. It was awarded the 120000 m2 facade contract 12 months ago. “Following the collapse of Schmidlin in Switerland several UAE companies stepped in to offer financial help to Schmidlin LLC UAE,” said a company spokesman.

Refuting claims it is to blame for the late supply of cladding the spokesman told iC, “We’re assembling the cladding now and have completed the test rig. We expect to start testing on Friday and, if the tests go as expected, could be on site next week. There are other concerns that have stopped us proceeding as planned, including design changes to the height.”

Speculation is now centring on the floor slabs and columns. “There are concerns over the structural integrity of the building. Certain calculations are being called into question,” said another source working within the project.

Countering this claim, Emaar’s project manager at the Burj, Greg Sang, told iC, “The timetable has been effected by the collapse of Schmidlin. We’re a little bit behind but we expect to put in place measures that ensure we’re on track to meet our original completion date.

"Normally you’d be looking to do a floor in three to four or perhaps seven days depending on the technical requirements of the job, we’re still working on the details but I expect to meet the dateline we’ve set with an accelerated installation timetable," said Mr Sang.

“Construction of high rise towers in the UAE usually sees the cladding contractor following on the concrete core as soon as possible. When a tower reaches 70 storeys, for example, the cladding should have reached the mid 40s,” said the project insider.

"You can drive past the building and you’ll see there’s no cladding, so you can draw your own conclusions as to when completion will be reached," he added.