Published On: Tue, Jan 21st, 2014

Don’t let rising damp ruin your residence

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Berwyn Evans, UK Product Manager at Rentokil Property Care discusses how homeowners can spot the tell-tale signs of rising damp

shutterstock_121553974One of the most serious problems in any home can be rising damp, which if left untreated can cause serious damage to internal decoration, such as cracked plaster, peeling wallpaper and rotting skirting boards or floor timbers.

Rising damp is caused by ground water and moisture that is drawn upwards, via capillary action, through porous building materials such as bricks, mortar or sandstone. This movement of water generates a characteristic “tide mark” and salts forming on the plaster due to the evaporation of ground water. The speed at which the moisture rises up the walls will depend on several factors – the type of wall material, the amount of water at the base of the wall and the environment inside and outside of the building.

It may not be obvious to spot at first and in many cases it can take several years before a problem is visible. However, there are a number of signs to look out for which may indicate there is a rising damp problem within your property. Damp walls and flooring can produce a musty smell, plaster can become stained or blistered, wallpaper and paint may peel. Other signs to look out for are decaying skirting boards which often fall apart as the nails and screws become rusty; wooden floors may start to decay, becoming soft and uneven.

Many reports of rising damp are actually down to condensation. The main differences being condensation can occur at higher levels in the property and can also result in the formation of mould; however the salts and minerals in rising damp normally inhibit the formation of these moulds.

Buildings in the UK should have a damp-proof course that acts as a barrier to stop water being drawn upwards within the walls of the property. Houses built after 1875 required a damp proof course to be installed as standard, however these damp proof courses can break down, over a period of time, which eventually leads to the failure of the damp course.

Many signs of rising damp only become evident long after the problem is embedded. By the time the situation is discovered, the damage can be extensive, inconvenient and costly to cure. Therefore the most cost-effective way to avoid these issues is by carrying out checks and performing regular maintenance.

If you do suspect you have a rising damp problem, you should call a professional who can conduct a detailed assessment and provide effective treatment for the damage. Below are some top tips and practical advice on how best to treat rising damp and eliminate it:

  • Ensure that external ground levels aren’t higher than the damp proof course; this can result in ‘bridging’ allowing water to enter brickwork or mortar above the damp course
  • Ensure that any brick walls erected on the property aren’t touching the main house, which again can result in ‘bridging’
  • Check that there are no leaking rain water pipes, which can result in damp penetrating through walls.
  • If mould is present in the property then the issue is likely to be condensation, which requires a different treatment solution to ‘true’ rising damp
  • Check for signs of dampness on walls and skirting boards. Rising damp on walls rarely exceeds one metre above ground level, but may go much higher in extreme cases
  • Always consult a professional to diagnose and treat rising damp


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