If left untreated, rising damp can cause extreme damage to the structure of your property. The cost of damp-proofing will be small in comparison to repairing your home interior and exterior fabric that you may have to replace. Rising damp can destroy decoration, plaster and can cause rot to the timber within your home.
How Does Rising Damp Occur? Rising damp is caused by moisture ascending through capillaries which are found in masonry. Capillaries are thin, lengthy tubes (pores) which are very small within the material. Within masonry, these tubes can often differ considerably in their thickness.
The most common and effective way to treat rising damp is to install a remedial damp proof course by injecting a water repellent damp proof cream into the mortar bed joint of affected walls.
Rising damp can be permanently eradicated from a property, but it's not something that's covered by home insurance.
For most people you do not need to be concerned. It might smell and look unsightly, however, the health risks are minimal. However, if the rising damp is extreme, it may lead to excessive amounts of black mould which may cause an allergic reaction, especially children, elderly people and those that have poor health.
Dehumidifiers draw excess moisture from the air, helping to combat condensation, prevent mould growth and reduce damp on walls.
The good news is that most cases of rising damp are easily treatable. There are two main ways in which this can be done but in all situations, we recommend calling in the professionals to help.
Signs of damp in a house
The appearance of mould or mildew on walls, floors or ceilings. Walls, floors or ceilings that feel cold or wet. Water droplets on walls. Dark or discoloured patches on walls or plaster.
Black Mould Appearing On Walls
Black mould on walls is a common sign of damp being a problem in a property. Black mould is often associated with condensation, however, if the mould occurs towards one specific part of the wall then this could be a sign that you have a rising or penetrating damp problem.
The most effective and economical way to treat rising damp is with a damp proofing injection cream. You can choose between complete kits or individual cartridges of cream from leading brands such as Kiesol C and Aida. The cream is injected or hand-pumped into specially-positioned holes in the mortar course.
An easy solution to cure damp on internal walls is to paint walls and ceilings with Dryzone Mould-Resistant Emulsion Paint. The paint damp-proofs internal walls against condensation and protects for at least 5 years from unwanted mould growth.
A Musty smell is one of the main signs of rising dampness. This smell is extremely unpleasant to live with and can be dangerous to your health. It also can worsen the conditions of those who have respiratory issues. Even if you cannot see the visible signs of the damp, you will still be able to smell it.
Rising damp affected walls can take up to 6 months to dry out for a 150mm thick wall and will even take longer for thicker walls. The general rule is that it will take one month for each 25mm thickness of wall to dry after the rising damp has been stopped.
Indeed in the damp proofing industry's own Code of Practice it states that “walls will take at least 6 to 12 months to dry out. The presence of paints or renders will substantially extend the drying period”.
Dampness which is caused by any sudden increase in the amount of moisture entering the building usually appears without warning — and in a matter of hours. It can also disappear just as quickly in the early days.
Dry the wall surface with a fan heater, then tape some kitchen foil tightly over the damp area. If the surface of the foil is wet after 24 hours, you have condensation. If the foil is dry but the wall surface beneath it is damp, you have rising or penetrating damp.
Rising damp is a form of damp that damages the walls of the property in an upwards motion from the ground. When the water from the ground rises via the walls due to capillary action, rising damp occurs. The water that is sucked up also has salts that travel through the walls.
Signs That You Need a Damp-Proof Course
Black spot mould forming on interior walls. This is a common sign also of a condensation problem. Watermarks on walls formed by either rising damp or penetrating damp. Plaster peeling off walls and damage to other decorative finishes such as wallpaper.
There are also two types of damp that should be eliminated before we talk about solutions to damp on internal walls. Those two types are: rising damp, and penetrating damp. If the damp patches rise from ground level, or there is a powdery deposit on wall surfaces, the cause is rising damp.
Yes, damp is generally worse in winter. Low temperature decreases the ability of the air to retain water vapor. As a result, it takes much less moisture for cold air to reach the condensation level at which damp becomes uncomfortable and creates favorable conditions for mold growth and structural damage.
How Long To Run Your Dehumidifier? So to recap, run your dehumidifier unit for at least 12 hours a day. This is a good rule of thumb. Again, it's okay if you don't stick to this schedule every day, but be aware that the more your family runs your dehumidifier unit the fresher and cleaner it will be all year long.
We're often asked 'does house insurance cover damp'. The answer to this question is most likely to be 'no'. It's not usual for buildings, content and landlord insurance policies to cover gradual deterioration, which is the category that damp problems generally fall into.