Copenhagen's highest tower, the 106 metre tower of Christiansborg Palace is having its concrete construction renovated and the copper cladding renewed. Until mid-2009, the tower will be covered in scaffolding, and when the project is completed, the tower will be copper-coloured like the roof of the Palace, with the only exception of the three crowns at the top of the tower.
Renovation of Concrete
Inexperience 100 years ago is the reason the concrete needs renovation. When the existing Christiansborg Palace was built, they did the outer half of the tower as a concrete construction, but the iron was placed too close to the outer edge of the concrete. This means that the concrete has chipped off so that the iron has been laid open and consequently rusted. The concrete now needs renovation to secure the construction.
Renovation is being done by tapping off all loose concrete where the iron is uncovered. Then the rust is removed from the uncovered iron, which is then treated with an anti-rust composition. The concrete construction is then repaired with a new and especially flexible type of concrete which is finally surface-treated with a material to make the concrete even stronger. The new concrete will be in the exact same shape as the old concrete.
Renewal of the Copper Cladding
The copper on the spire of the tower is being renewed at the same time as the concrete is being renovated. It is rational to carry out both things at the same time, one reason being that it is necessary to remove a large part of the copper sheets, which have been worn thin, in order to reach the concrete construction. The ornamentation of the tower, which is carried out in far thicker copper plates than the cladding, will not be renewed. The copper ornamentation will be taken down and subjected to glassblowing so that it gets the same colour as the new copper.
The three crowns will remain in the green colour they have now, as they were fitted much later than the rest and are expected to last a long time still. In this way, passers-by will be reminded of the green colour the roof and tower of the Palace were meant to have.
100 Years' Durability
The new concrete is expected to last 100 years, and the copper should last even longer, even though the climate is extraordinarily rough on copper which is located high up in the air. Copper holds the great advantage that the material can go many years practically without maintenance.
Read more about Christiansborg Palace here.
Last updated:: Wednesday, July 22, 2009
