In most homes, damp is caused by one of the following issues:
Poor ventilation
Why does this happen?
Moisture is generated in any house – through washing, cooking, drying laundry and even breathing. To keep your home feeling dry and comfortable, moist air needs a way to escape the building. If it can’t escape, it builds up within the home creating condensation.
The way homes have been built and renovated in the past has made it more difficult for any moisture to leave the building. This can happen in modern buildings, which are often well insulated and designed to keep warm air in, but don’t provide sufficient escape routes for moisture. It can also occur in older properties where the addition of new insulation, windows or doors has blocked or disrupted escape routes.
What are the signs to look out for?
Condensation on windows, cold walls and surfaces (such as tiles) and a cool, damp feeling within your home.
How to fix this
Reduce condensation, repair and prevent further damage from moisture.
Penetrating damp
Why does this happen?
Sometimes the weatherproofing of a building can let you down. Common causes include leaking roofs (from broken or loose tiles, or damaged flashing on older buildings), leaking gutters (where the gutter has come loose or is blocked with leaves and debris) or damaged and deteriorating mortar, render or pebbledash on exterior walls.
What are the signs to look out for?
The sudden appearance of a damp patch (that often looks like a brown stain) on the inside of an exterior wall, in the upper corners of a room, on a ceiling or near a chimney breast.
How to fix this
Find out the source of the problem and make repairs to prevent further water ingress. We have a number of guides that can help, or you can get a professional in to sort this for you.
Leaking plumbing
Why does this happen?
If your plumbing is old or loose it can cause the hot or cold water supply to leak. There could also be a problem with waste water or central heating pipework that can cause anything from gushing water to a slow trickle of damp.
What are the signs to look out for?
Similar to penetrating damp, this damp appears away from the external walls and corners of a room as a growing damp patch. It’s mostly likely to occur on a ceiling or beneath a radiator or sink.
How to fix this
Start by fixing the cause of the problem – our handy guide to dealing with plumbing problems offers advice on some of the most common.
Rising damp
Why does this happen?
Rising damp usually occurs in older homes (early 20th century or older). In modern properties, damp-proof courses are built into the footings and foundations of a home. These help to provide a barrier between the moist soil below the house, and the habitable areas above. In older properties however, damp-proof courses may be less substantial or not part of the construction. This means that brick walls can absorb moisture from the ground below, allowing damp to rise into the floors above. The addition of modern plaster, insulation, windows and doors in more recent years may also have weakened the building’s ability to breathe, trapping moisture in the walls.
What are the signs to look out for?
Cold, damp surfaces and mould growth in the external corners of ground-floor rooms. Cold walls and floors, as well as a musty smell.
How to fix this
For homes with considerable rising damp, installing a modern damp-proof course is the best solution. Whilst this can be an expensive option, it will help to prevent any further deterioration of the building and reduce the need for preventative measures in future. Consult an expert to find out the best option for your home and budget. Where symptoms are milder, rising damp can be managed in a similar way to issues caused by condensation.
