How to Fix Damp at Home

How to Fix Damp at Home

Nobody wants to live in a damp house, but for many people, it is a real problem. Of course, damp can easily develop in any home when the conditions allow. Damp is simply unwanted moisture in the walls, ceilings or floors of a property. It can affect a home inside and out. Not only can damp cause damage to brick, wood and concrete but it can also harm the furnishings too. So, how can you fix damp at home?

Luckily, it is possible to prevent and treat damp. If there is damp in your home you will notice some visible signs and a musty smell. If it is left untreated, it can make your home unhealthy. For the sake of your household, it is important that you keep damp at bay.

The reasons for damp vary according to the age and condition of the building. In general, old buildings must be allowed to breathe. This means that any moisture that is absorbed evaporates back out. Newer buildings also need ventilation, but water is kept out with a system of damp-proof barriers.

So How Do You Prevent Damp?

The main causes of damp are:

  • Condensation
  • Penetrating damp
  • Rising damp
  1. Condensation is a common cause of damp inside the home. Modern lifestyles can create huge quantities of water vapour. This is caused by everyday activities such as cooking, washing, bathing and drying clothes indoors. Where there is not enough ventilation, damp may occur as warm moist air condenses on cooler walls. 

Condensation: Remove regularly


Simple measures to reduce condensation can include opening windows and using trickle vents. Wipe wet surfaces including the inside of windows. Install extractor fans and use a dehumidifier to help to reduce water content. Try to keep your home at a constant temperature and avoid putting clothes on radiators to dry. Don’t forget to keep lofts well insulated and ventilated.

2. Penetrating damp is caused by rainwater. This can be the result of leaking pipes or missing or broken roof tiles. Defective lead flashings, pointing or rendering and hairline cracks in the walls can all cause damp too. Badly fitting window frames can let in water. Sometimes wet weather and wind can breach a wall and cause damp. This occurs mostly in older buildings. This is because they are more likely to have solid walls than cavity walls found in newer homes. Cavity walls help prevent moisture from coming through.


The best way of preventing penetrating damp entering the home is to keep your property in good order. Check the roof for broken or missing tiles, clear the moss from roofs, check the flashing around chimneys and clear gutters. Repair damaged window frames or cracked rendering on the walls. Be aware that blocked cavity walls in modern properties may also let moisture through.

3. Rising damp from the ground outside can move up walls of ground floor rooms or basements. It does this through capillary action, bringing mineral salts with it. This is more likely to occur in older properties, especially if the building cannot breathe properly, so trapping moisture in the walls. Floors can become damp if moisture from below is unable to escape through them as water vapour. Carpets and vinyls can cause this barrier too.


Check if you have a damp-proof course (DPC), which stops water rising into ground level floors and walls. Look for this about 6 inches above ground level. You should see a line of slate or plastic running horizontally across the brickwork. If the DPC is not working effectively it may need to be improved or replaced. Also check that there is no dampness from the ground surrounding the DPC. It should not be built up above the DPC level. Make sure there is no water run-off from surrounding paths or patios.

What are the Symptoms of Damp?

You may notice a damp, musty smell in your home. The walls may appear wet and be cold to the touch. Paint and wallpaper may be peeling or blistered. You might see mould or on the walls (especially in the corners where there is no ventilation). On some walls you might see tidemarks or feel mineral salts deposited if you run your hand across them. Ceilings may be discoloured and wooden skirtings damaged.

Wallpaper peeling could be a sure sign of damp

You will need to find the source of the moisture and get any major damp problem treated. If you are unsure where it comes from it is best to get professional help. Specialist damp-proofers can assess and diagnose the problem by testing and analysis then help you put the problem right.

Remedies for Damp

There are advantages and disadvantages to all damp-proof treatments. The remedy will depend on your property, how it is constructed and the state of the DPC.

  • The most common remedy for a missing or damaged DPC is to use chemicals. A specialist will need to drill holes into your wall to treat the problem. Damp-proof paste is then injected into the drilled holes to act as a new barrier. This can be at different heights or in specific areas, such as a weakness in the wall.
  • A physical remedy is to cut horizontal grooves into the brickwork and install a new DPC. The DPC is placed in the groove, bedded on the mortar. This is a much more invasive process than drilling holes and the results are less easily hidden. It is however a very reliable method of preventing damp.
  • A further remedy is to use a damp-proof membrane. This membrane is laid underneath the floor and connected to the DPC so that the house is sealed against water rising from underneath.
  • If cavity walls are blocked you can get the cavities cleared. This will prevent damp from the outer walls reaching the inner walls.
  • And of course, to help with condensation you could have new vents or extractor fans fitted in the kitchen or bathroom.

Find a local expert to help if unsure

A Final Word on Damp

Damp can be a complex issue and there may be more than one solution to a problem. You might even be able to remedy the problem for free by tracking damp problems and finding the cause without specialist help (such as for condensation and types of penetrating damp).

Some of the remedies for damp problems can be expensive and intrusive, especially for rising damp. Fortunately, this is one of the least common forms of damp in the home.

It can be a good idea to monitor the damp situation for a while so you can be more confident about the cause of your damp problem. You can try out preventative measures before you call a specialist.

But do remember that to treat damp effectively you will need an accurate diagnosis.

Once you decide to get specialist help, be wary of taking on unnecessary damp treatments. It can be useful to get in several reports, quotes and recommendations for the work before you go ahead.

Always check out your local professionals using for a tested, trustworthy and reliable service.

Good luck with your damp-proofing!