Rising damp can lead to both minor and serious problems if untreated. Normally it occurs in older houses where no Damp Proof Course exists, or if it has been damaged due to age or other factors. It is a dampness that rises by capillary action in building walls and can carry with it nitrates and chlorides, which are a type of hygroscopic salts that can cause further problems.
The nature of the salts makes them able to absorb moisture from their environment and crystallize causing deterioration to the plastering, discolorations to the walls, wallpaper and paint loosening and other secondary damage to the house. The moisture in the walls creates a perfect environment for variety of fungi, wood rot and mould which can cause health hazards in the long term.
Damp Proofing Solutions
To get rid of the problem permanently there are things that can be done. Initially the problem of rising damp needs to be resolved, which can be done by a process called damp proofing. This protects the walls and creates a barrier that will stop dampness from travelling through.
Damp proofing is carried out by the application of a course of a special chemical substance to the inside of the walls which then expands and releases gaseous compounds of silicon and hydrogen that later react with the wall, creating waterproof resin.
Another thing that will need to be done is the treatment of any damp walls inside of the building. Old plaster layers may need to be removed to allow the walls to dry, be treated properly and to stop the hygroscopic salt cycle which can retain moisture if the salts remain.