The issue of condensation, damp and mould is in many cases down to lifestyle and can be resolved by a few simple changes. However, where the problem is excessive it can be caused by other issues such as uninsulated solid walls, inadequate loft insulation, lack of trickle vents on double-glazed windows, single-glazing, and inefficient heating systems or leaking gutters and downpipes.
This is the most common cause of dampness in a house. Condensation is caused when moisture or water vapour in the house comes in contact with a cold surface, such as a mirror, window or uninsulated solid wall. If the moisture is not cleared away it may soak into the surrounding wallpaper or paintwork. Water vapour is produced by many common household activities such as cooking, drying clothes indoors, bathing, and small amounts even by breathing. Usually, condensation occurs during cold weather in places with little air movement. It is commonly found behind wardrobes inside cupboards or near windows. If left it can turn into mould with spores that can harm your health
Penetrating damp is when water makes its way into a building from the outside. Moisture can enter the building in a number of ways. Some examples are, leaking rainwater pipes, damaged roofing, blocked gutters, gaps around window frames or cracked or defective rendering and brickwork. Issues such as these will require repair or remedy.
Rising damp can occur in solid walls or in cavity walls if the damp course fails. This is where groundwater rises through the walls of your house creating a ‘tide mark’ up to one meter from the floor. This will require specialist repair
Damp or condensation caused by the previous issues can lead to mould growth. This appears as a patch of little black dots in the area affected. A build-up of mould can cause health issues especially respiratory illness. If a build-up of mould has occurred, it can be removed using diluted bleach or a special fungicidal wash. When doing so always remember to use appropriate protection such as rubber gloves and safety glasses. Specialist paint can be applied to help delay the growth of mould. Although condensation and mould can be removed it is more beneficial to identify where the moisture is coming from and address those issues as it will help prevent future reoccurrences.
There are three main ways you can prevent damp and mould problems in your home. Firstly, condensation is often a problem in under-heated houses. Although you may want to reduce the cost of your heating setting the thermostatic radiator valve (TRV) to 1 in the rooms that you are not using will prevent the room temperature from becoming too low when the rest of the house is heated. If you do not have a central heating system, consider using a room heater with a timer and temperature control instead.
Secondly, insulating your loft, walls and draft-proofing doors and windows will reduce cold spots along with making your house cheaper and easier to heat. As described condensation occurs on cold surfaces so warming these up will reduce the problem. Insulation also has the benefit of reducing heating costs and health risks associated with excessive cold
Finally, a well-ventilated house will help reduce moisture by allowing air circulation throughout. Be sure to include the inside of cupboards and wardrobes. If your windows have trickle vents, make sure these are opened and make sure fan ventilation is turned on in bathrooms and kitchens while conducting moisture-producing activities
Moisture Producing Activities
The day-to-day things we all do in our houses add moisture to the air. Simple things such as a night’s sleep will add half a pint of water to the air per person. Some other activities that put moisture into the air are
- Bath or Shower – 2 pints
- Drying clothes indoors – 9 pints
- Cooking and use of kettle – 6 pints
- Washing dishes – 2 pints
- 2 people in the house for 2 hours – 2 pints
- 8 hours use of bottled gas heating – 4 pints
Tips and Tricks
Some final tips and tricks to help reduce moisture production include
- Cover pans when cooking and do not leave the kettle boiling if it does not automatically turn off. This will also help you save some money on your energy bills
- Avoid using paraffin or bottled gas heater. A litre of gas produces a litre of moisture
- Dry clothes outdoors or put them in the bathroom with the door closed and window open. If you have a tumble dryer, ensure it is vented outside
- Keep kitchen and bathroom doors shut to prevent moisture from moving around your house
- After having a bath or shower ensure the bathroom door is closed and the window open until all the moisture is gone
- Use an extractor fan or open a window in the kitchen while cooking
- Do not block air vents or trickle vents in windows. This will cause condensation as the moisture has nowhere to escape. Wiping down windows and sills in the morning will also help but be sure to wring out the cloth rather than dry it on a radiator. Dehumidifiers may also help but incur running costs
- Position furniture against internal walls where possible