Damp & CondensationFrequently Asked Questions

How can I avoid condensation and mould?

By October 27, 2017 No Comments

You can control the condensation in your home by:

  • ventilating your home every day
  • reducing the amount of moisture your household produces
  • heating your home adequately

If you have a hygrometer from Town & Country Housing, keep the two dials within the green zones at all times. If the temperature of your home is likely to fall into the blue zone (below 18°C), the ideal humidity level to avoid condensation and mould is between 30% and 50%. A humidity level over 60% can put your home at risk of mould growth.

1 Ventilating your home

Your household can generate a considerable amount of moisture which goes straight into the indoor air of your home. To remove it, you need to take action to ventilate your home. This also helps to improve the air quality and provide a healthy indoor environment.

Open your windows

  • Open your windows every day throughout your home for (at least) 30 minutes. You can split the time e.g. open them for 15 minutes in the morning and again 15 mins later in the day. Keep the internal doors open to allow the free flow of air through the property. Even in the winter, outdoor air is much drier than indoor air. When you open the windows you allow the stale, moist air to escape and fresher, drier air to enter.
  • You may need to open the windows wider and for longer if your home has become very damp through condensation; if the humidity level in your home is high; or you have a lot of people living in your home.
  • Double glazing and insulation will make your home easier to heat; however, it makes your home more air tight. Therefore, any moisture that builds up in the air inside your home does not escape easily unless you ventilate your home.
  • Keep the trickle vents on your windows open at all times. If you don’t have trickle vents, try to keep a small window slightly ajar during the day when you are home. This provides background ventilation in your home and it is needed for extractor fans etc. to work effectively.

Open your curtains

  • Open your curtains every day. Net curtains can impede ventilation, so try to move them out of the way when opening your windows. Drawn curtains make the surfaces within the entire window area cooler and, as the air circulation is restricted, it increases the risk of condensation.
  • Try not to let your curtains block the heat from your radiators. Curtains in front of radiators block the heat and act as a barrier to the effective heating of the room.

Consider the position of furniture

  • Position furniture and goods against internal walls (i.e. walls which have a room on both sides), and keep a good gap between the furniture and the wall. If you do have any furniture against external walls, leave a gap of around 12.5 centimetres all around the furniture and the external wall & floor. This allows the air to circulate under and around the furniture and helps to prevent ‘dead’ air spaces, where condensation will occur and mould and mildew will grow.
  • Always think about the safety of the pieces of furniture, particularly if you have small children. You may need to consider securing heavy and larger pieces of furniture to the wall.

Cupboards and doors

  • Open the doors of cupboards and wardrobes for a while regularly. Also don’t fill them with too many things.
  • When you open the doors and ventilate the cupboard or wardrobe, you allow moist air to escape and fresher, drier air to enter. Doing this regularly for 30 minutes or more, and if possible every day, will help to prevent mould growing on the items.
  • If you fill cupboards with too many things, the air can’t circulate between the items and you will end up with ‘dead’ air spaces, where condensation will occur and mould and mildew will grow.
  • You may need to remove false backs on built in cupboards, or drill breather holes in the furniture to allow the air to circulate.
  • Do not block any permanent ventilators/air bricks in your rooms. These ventilators help to improve the ventilation in your property. They help the moisture in the air to escape.
  • Except when cooking, bathing and showering (see cooking and bathroom sections above), and for 30 minutes afterwards, try to leave all the internal doors open during the day. This allows the drier air you have brought into your home from ventilating the property to circulate throughout.

2. Reducing the amount of moisture in the air

The following tips will help to prevent excess moisture getting into air of your home.
Bathrooms

  • Close the bathroom door when it is being used for bathing or showering.
  • When you are finished, open the window or put the extractor fan on, and keep the bathroom door closed for at least 30 minutes.
  • Put cold water in the bath first, then the hot water. This reduces the amount of steam produced.
  • Avoid long, hot steamy baths or showers, which will put lots of moisture into the air. For showers, water companies recommend 4 minutes as enough.
  • Wipe down toilet cisterns, tiles and mirrors with a cloth if they are affected by condensation. Don’t put that cloth on a radiator to dry, as this just releases the moisture straight back into the air.
  • Leave the toilet seat down to allow the air to circulate around the cistern and back of the toilet

Cooking

  • Close the kitchen door and open a window or turn on your extractor fan when cooking. Leave the fan on or window open for approx. 20 minutes afterwards.
  • Put lids on pans
  • When washing up, put the cold water in first, then the hot. This reduces the amount of water vapour produced.
  • Don’t leave kettles or pans boiling for longer than necessary.

Drying washing

  • Put washing outdoors to dry.
  • If you have to dry clothes inside, put them on a rack by a window or in the bathroom. Make sure you keep the door to the room shut, and open the window or turn on the extractor fan.
  • When using a tumble dryer make sure you vent it to the outside, preferably by connecting the hose to a permanent vent in the wall. If you hang the hose out of the window the humid air that comes out of the hose can blow back in through the window, particularly if it gets windy.
  • If using a condenser dryer make sure you ventilate the room well (e.g. window open and door to the room closed)
  • Don’t dry washing in airing cupboards or on radiators

Wipe down windows

  • Wipe the windows and window sills of your home every morning to remove condensation. Just opening the windows is not always enough.
  • Don’t put that cloth on a radiator to dry, as this just releases the moisture straight back into the air.

Extractor fans

  • If you have them, use them. Don’t turn them off at the power switch.
  • If your extractor fan stops working, report it straight away. Make sure you ventilate the property using your windows whilst waiting for it to be repaired.

Steam generating appliances e.g. irons, steam cleaners

  • Try to ventilate the room in which you are using them (i.e. open the window) and close the door to stop the moist air getting out into other rooms

Fish tanks

  • Make sure that fish tanks have a well-fitted cover, otherwise the water will evaporate into the air and increase the humidity of your home.

3. Heating

  • Ideally keep the average temperature between 18-22°C, not only in terms of condensation, but for your own health if you are over 65 or have health issues
  • Warm air can hold more moisture than cold air. Heating will help to keep the internal surfaces of your home above the dew-point temperature.
  • Cold homes can have a significant impact on people’s health. If you are 65 and over, have a health condition, or have limited mobility you should heat your home to a temperature of at least 18°C. If you are younger and in good health, a lower temperature is safe so long as you are comfortable.
  • A lower heat for a long time is better than switching your heating on high for a short period
  • Heating warms the surfaces of your home and helps to keep them above the dew-point temperature.
  • Intermittent heating causes variations in temperature. Once the heating is turned off, the temperature of the air and the building will start to go down. As the air cools, its ability to hold water reduces and when that air hits a cold enough surface it condenses. Mould and mildew will follow within days.
  • If you have a room thermostat or thermostatic radiator valves, you can use them to control the level of heat.
  • If you have Economy 7 or Electric Storage Heaters try to allow a gradual heat output throughout the day. Check the instructions, if you have them. For most, there will be 2 knobs: the right hand knob controls the heat input and the left hand knob controls the heat output.
  • Try to heat the whole house. Do not heat up cold bedrooms in the evening by opening the door to allow heat from the rest of the house to get in. The warm, moist air from elsewhere in the home will travel invisibly into the room on the air currents and condense on the cold surfaces of the bedroom.
  • Don’t use your gas cooker, portable gas heaters or paraffin heaters for heating. They all produce moisture when in use and can add a considerable amount of moisture into the air.
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