Causes and Remedies for Damp and Humid Conditions in Dwellings

Damp can occur in any home which is why knowing how to stop condensation is important information for every homeowner. Whether damp is caused by internal or exterior troubles or failure to keep up with house maintenance, if you do see signs of damp, it’s best to get to the bottom of the problem as soon as possible.

Identifying the problem

Damp is one of the most frequent problems to arise within a home. There are three major types of damp to be aware of:

  • Condensation
  • Penetrating Damp
  • Rising Damp

Each one has a separate cause and remedy.

Condensation

Condensation takes place when excessive moisture cannot escape from the building. It occurs when warm air meets a cold surface and condensates into water droplets. A clear indication of condensation is black mould forming on hard surfaces or the presence of a musty smell.

What can cause Condensation?

Condensation is most commonly caused when a building is not kept ventilated. Activities that produce large quantities of water vapour cause condensation, such as:

  • Drying clothes inside the house (covering radiators/heaters)
  • Steam from cooking and from bathing/washing
  • Lack of air circulation and ventilation in the building (Humid conditions)
How can I reduce Condensation in my house?
  • In cold weather low back ground heating on all day will help keep the fabric of the building warm and reduce moisture condensing on cold spots
  • Improve ventilation by fitting and using extractor fans in bathrooms and kitchens and ventilators in the loft
  • Avoid drying clothes in the house and cover saucepans whilst cooking
  • Use a dehumidifier. This is a device that draws in air, cools it to remove moisture, which is collected in a reservoir and reheats it at an acceptable temperature before re-circulating it
How do I clean Condensation?
  • Remove water droplets with a sponge
  • Clean with an anti fungal cleaner or bleach based product. The product should be applied to the affected area and left for several minutes then thoroughly washed down with hot water.
  • Redecorate using a good quality fungicidal paint to help prevent re-growth
  • Dry-clean mildewed clothes and shampoo carpets

Penetrating Damp

Penetrating damp is as a result of water getting into the house from the outside. This is normally as a result of a plumbing or building issue. A common indicator is damp patches appearing on the walls or the ceilings and is often worse after rain. It can form due to faulty roof coverings, poorly maintained walls, poor guttering and down pipes and gaps around doors and windows. Penetrating damp tends to occur in older homes with solid walls, as those most recently built will have cavity walls offering more protection.

How do I prevent Penetrating Damp?
  • Ensure guttering and down pipes are kept in good repair and are free of any blockages
  • Make sure any external walls are painted with good quality paint
  • Ensure that gaps around window frames and doors are filled
  • Check roof tiles and rendering regularly to ensure they have not become damaged and there are no entry gaps

Rising Damp

Rising damp usually occurs in dwellings that do not have a damp proof course or where the damp proof course has failed. The usual evidence of rising damp is a whitish fluffy powder or distinguishing marks on the lower section of the walls. The plaster may become softer and mould may start to grow. A musty smell may be evident.

How can I reduce Rising Damp in my house?
  • Make sure there is no earth from the garden against the wall that could be trapping moisture
  • Make sure none of the drains are blocked causing a build up of debris
  • Repairs or input of damp proof course could be required; the opinion of a damp proof specialist should be sought

For more comprehensive advice we suggest consulting with a business that specialises in damp prevention or your local council environmental health office.