Damp Patches On Internal Walls

Have you recently found damp patches on the walls of your bedroom or living room?

Sometimes damp on a wall in your home can mean expensive repairs - plaster and paintwork might need to be replaced, and you may also need to remove any mould that has started to grow.

There are a number of factors that can cause damp including penetrating damp  where water from outside gets into the brickwork through gaps and cracks. If the patches are clustered around windows and doors, then it's likely that rain is getting in through gaps around the frames.

Damp can cause serious damage to both the appearance and structure of your home and can also lead to health problems.  If damp is not treated properly, it can lead to the deterioration of masonry, cause plaster to crumble, and cause wooden beams and floorboards to rot, as well as causing paint and wallpaper to peel away from walls. 

Many damp issues arise from poor ventilated properties, you can usually spot a damp affected area by having cold spots or feeling wet to the touch.  

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 loft and wall insulation in an old building 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.

Whilst insulation is great for making top floor rooms warmer, it comes at the cost of making your loft or roof space cooler. Condensation in lofts occurs when humid air makes its way through insulation or other gaps into the loft space and hits a cooler surface leading to beads of moisture on timbers, lintels and on the underside of the roof.

As a quick tip, if you are looking to re-insulate the loft space to improve the energy efficiency of your property, use thermal insulation with a vapour barrier a vapour barrier fitted on the “warm” side of the insulating material. As with other rooms in the house, condensation in the loft is caused by excess moisture in the air and a lack of adequate air ventilation. Have a look at our top reasons this may occur in the loft:

• Additional insulation has been laid down in the loft restricting the natural air circulation in the property, meaning lofts stay much colder than the rest of the house, so humid air is more likely to deposit its moisture on surfaces in the loft.
• Roof vents have been covered or blocked by storage boxes or other items stockpiled in the loft.
• Hot water tanks releasing steam and moist air into the loft or roof space.
• Steam from activities such as bathing and cooking combining with a lack of general ventilation to create excessive moisture rising into the loft.

Condensation damp 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 - 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 solution to cure damp on internal walls is to paint walls and ceilings with a mould resistant emulsion paint. The paint adds another damp-proofing element for internal walls agains condensation and helps to prevent unwanted mould growth. 

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?

Penetrating damp often occurs as a result of issues with the exterior of your property.  Ensuring that you regularly check that the pointing between bricks and external paint is kept in good condition, and check for draughts around windows and doors - if air can get in, then so can moisture.

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.

Improvements to home efficiency in the form of double glazing and additional layers of insulation in our lofts can also make our homes more air tight, which in turn causes moisture levels to rise, and without sufficient ventilation, this can lead to problems with condensation.

If the problem doesn't fit the pattern of either rising or pentrating damp, then it is most likely caused by condensation.

If you are the owner of the home or a landlord with multiple property we can help.  Our local specialists can conduct a free home survey where we will visit your property and check the damp patches on your walls.

As the majority of damp patches are actually caused by excess moisture in a property, we have also written a useful guide which offers 14 top tips to reduce condensation problems which you may find helpful.