The Hall Roof is Sealed

Like a mountain flank a sophisticated roof construction closes the ceiling of the large concert hall. A pity, though, that it will never be seen. A report from the Elbphilharmonie building site.

Just in time for the beginning of autumn the roof of the large concert hall is now closed. 15 meter high and covering a span of 50 metres it covers the tip of the large concert hall between the residential area and the hotel zone of the Elbphilharmonie.

More than 100 prefabricated concrete slabs, each of them designed individually due to the asymetric shape of the tip and up to twelve meters long, have been assembled around the »flap«. Before the final completion of the hall roof, steel ropes were integrated into the statically advanced steel construction, and afterwards the gaps were filled with concrete. The dead weight of the steel and concrete construction is 2.000 tonnes.
Though later the tip will not be visible any more. The covering of the building will conceal the hat and the complex ventilation, air conditioning and electronic systems will be accommodated inside, adding additional thousands of tonnes to the weight. But the concert audience will be able to admire an awe-inspiring organic arch without any supports when looking up to the ceiling from below.

The hall's interiour is currently occupied by a steel birdcase scaffolding. Little is to be seen of the spectator stands, steeply intertwining upwards. 14 meters above the future concert stage a work platform is installed, presently to be reached by ladders. From here the hall tip is concreted from the inside. 60 steel spring packages have been installed beneath the hall tip, providing the only connection between the roof construction and the hall. Their purpose is to accoustically separate the hall from the building A total of 362 steel springs have been applied at special contact points around the hall, preventing disturbing noises from entering inside.