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Damp Patches On Interior Walls

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By EnviroVent Feb 03, 2019

If you have recently found damp patches on the walls of your bedroom or living room there could be several causes including damaged guttering, cracked roof tiles and more commonly condensation.

If you do find damp problems in your home it is important to find the source of the problem and get it treated as soon as possible.

Damp can cause serious damage, not only to the appearance of home but to the structure of the property and your health. It can lead to the deterioration of masonry, cause plaster to crumble, wooden beams and floorboards to decay and leave bubbling on your wallpaper.

Unfortunately, inappropriate treatments for damp problems commonly cause more damage and leads to unnecessary expense through the installation of damp proof courses and sealing up walls rather than improve their ability to breathe.

It is important to understand the difference between old buildings and new builds in order to remedy the damp patches that are appearing in your home.

1. Old buildings are designed in such a way that they must be allowed to breathe.
2. New builds work on a system of defensive barriers which keep moisture out.

Installing insulation in your loft and walls will keep it warm in the winter months but it will also cause your home to sweat which is when problems start to happen and damp patches start to appear on your walls and ceilings.

This type of damp is called condensation, and is more commonly found on windows when the warm air circulates around a property and lands on the cold window panes which forms water droplets known as condensation.

There are however two other forms of damp that need to ruled out before we can confirm that the dampness inside your house is indeed condensation.

1. Rising Damp
2. Penetrating Damp

If the damp patches on your walls appear to rise up from ground level or there is a powdery deposit on wall surfaces close to the floor, then rising damp is probably the culprit. Rising damp usually occurs due to a failure or absence of a damp-proof course. It is very unlikely you will suffer from rising damp if you live in a flat above ground level as the damp has to come from the ground level.

How do you treat rising damp?

Improve the drainage of the site where the property is situated. Ensure that the ground surrounding the building is sloping away from your property and then check to make sure there is enough room under your floorboards for moisture to evaporate from the soil below.

Another form of damp is penetrating damp. If your interior walls are damp and it seems to be isolated to one area of the wall then it is likely a result of water from outside getting into the brickwork through cracks or gaps in the outside walls.

How do you treat penetrating damp?

Regular maintenance of your external walls should stop the damp from penetrating through in the future. Ensure the pointing and both internal and external paintwork is kept in good condition and make sure you seal the gaps around window and door frames.

If you have ruled out both of the above types of damp and there is no damaged guttering or missing roof tiles then it is more than likely that your property is suffering from condensation.

As we try to make our homes more energy efficient with double glazing, loft insulation and damp proofing we are also making our properties more airtight. This causes moisture to build up indoors and humidity levels to increase which is due to inadequate or indeed a lack of ventilation and over-efficient improvements to our homes.

If it doesn't appear to be rising damp or penetrating damp then those damp patches that suddenly appeared on your interior walls are probably due to condensation.

If you are the homeowner or a landlord with several property we can confirm that the problem is indeed condensation by arranging a free home check where we will visit your property, carry out a relative humidity test and inspect the damp patches on your walls.

We have also written a great article featuring 14 ways to reduce condensation problems which you may find helpful.