Damp basements cut in two 

Many females would probably consider cutter Ejler Degnebolig and his team's work in a basement in central Copenhagen to be a serious waste of precious stones. Their most important work tools are two diamond chainsaws that are being used to cut the basement in half.

The small, one-carat diamonds are cutting through the reinforced brickwork in the basement of a cooperative housing block in Copenhagen’s Burmeistergade. The basement is the site of a demonstration project to test a method of stopping clear signs of rising damp such as mould fungus in ground floor flats, rot in supporting wooden beams, and stains on outer walls from salt and rising damp.

An effective alternative

The method – not previously used in Denmark – provides an effective alternative to traditional methods, which are not 100 per cent guaranteed to stop rising damp from groundwater. The idea is to insert a stainless steel plate into the wall and seal it with mortar, so that all the difficult corners can be reached.

This method spares the building and minimises the risk of damage, as the opening is cut transversely through the wall in direct opposition to the traditional method of driving a steel plate into the wall.

Far too often, urban renewal projects waste money by damp-proofing the outer basement walls to prevent rising damp in the wall or laying a drain around the basement. But these methods do not prevent all rising damp, which often originates from groundwater. Consequently water continues to seep up from the basement, despite the fact that the outer basement walls are damp-proof.

A growing problem

"Most old houses with brick foundations have a problem – and it is a growing problem," explains Project Manager Rune Christiansen of the Urban Renewal Company. "With the advent of penthouses, today we use roofs much more intensively. Consequently many attics have been closed and we are increasingly storing furniture, books and clothing in dry cellars. More people also wish to use their basements as workrooms or meeting and conference rooms. This places greater demands on basement structures."

Discovering rot is a serious problem

COWI Project Manager Michael Per points out that the two traditional methods of stopping rising damp have a number of drawbacks. The chemical method, which involves injecting a substance into the brick foundation, has had no documented effect so far.

The mechanical method, where a stainless steel plate is inserted into a horizontal joint, needs to be further developed. There is often no horizontal joint into which the plates can be inserted or vibrated. Not to mention that the vibrations caused can damage the wall.

By Christina Tækker, cht@cowi.dk
Posted 04.05.2005