Rising Damp

A large number of older buildings and some new ones have problems with rising damp. Rising damp can cause flaking paint, peeling wallpaper and musty odours.

Bricks and mortar contain small pores and therefore have the capacity to soak up water in much the same way as a wick.  Ground water in contract with the base of a wall will therefore tend to rise up and into the wall unless an impervious barrier such as a damp proof course prevents it.  The injection of a chemical damp proof course is the most popular method of introducing a new damp proof course into an existing building. The process works by modifying the surface tension as a result of coating the capillaries within the brickwork with a water repellent material. The water repellent material is injected as a liquid or cream into holes drilled at the appropriate position and centres at the base of the wall to be treated. 

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An additional complication brought about by rising damp is that ground water invariably contains dissolved salts. As evaporation from a wall takes place these salts become concentrated at the wall’s surface, i.e. in the plaster. The presence of these salts in the plaster means that even if the further rise of moisture is controlled there is still a strong possibility of decorations being spoiled because some of these salts (chlorides and nitrates) are hygroscopic. This means they have the ability to absorb moisture from the atmosphere. A salt contaminated wall surface will become damp during wet weather or humid conditions giving the impression that the damp proof course installation has not been successful. As part of the treatment process it is therefore essential to remove the contaminated plaster and for it to be replaced with plaster to a particular specification.

Damp treat Ltd can take care of the whole of this process for you from the removal of old plaster, to the injection of the new damp proof course and re-plastering.  Alternatively if you wish to do part of the work yourself e.g. the removal of the old plaster we will quote for the remainder of the process.