Condensation

Condensation

This is the most common cause of dampness people experience in their rented homes. Most people will see black mould or water droplets and assume there is a water leak, or it has come from outside - it hasn’t!

What is it?

Condensation occurs when moisture or water vapour in the air meets a colder surface, such as a window, wall, or mirror. When this happens water droplets (condensation) can soak into the surface they touch. Mould spores may then land on these damp areas causing mould growth. Mould is a common fungus that grows on clean water, for example, untreated condensation.

How is it caused?

Condensation and mould growth are often due to the lifestyle of the inhabitants. Simple changes to their actions or activities can reduce the amount of moisture in the air.

A properly ventilated and heated property is also less likely to have these issues. When the external temperature is low, such as during the colder months, condensation is more likely to occur. This is because cold air cannot hold as much moisture as warm air.

Where is it found?

It is usually found on:

• The corners of rooms
• Cold external walls
• On or around windows
• Areas of poor air circulation such as behind furniture or inside wardrobes
• Sometimes it can be at skirting board or ceiling level where the junction of two internal walls meet

How to spot condensation

• Damp patches with no clear edges
• Staining from running water
• Crescent shape (at skirting board or ceiling level where the junction of two internal walls meet)
• Mould growth
• Musty smell

Warmth versus Ventilation

It is very common to find that occupiers do not ventilate their home when the heating is on, as they do not wish their heating to go straight out the window! Finding a balance between warmth and ventilation in a property is extremely important. Although it may seem that you are losing heat you are creating the optimum conditions for a healthier living environment.

Opening windows to ventilate a property (as well as following the tips below to reduce moisture) allows warm moist air to escape and cool dry air from outside to enter your home. By doing this you will save money as dry cool air is cheaper to heat than warm moist air.

Tips to Reduce Condensation

Managing condensation is not easy. It is advisable that you follow as many of the tips below as you can and incorporate them into your daily lifestyle. This will create a healthier living environment for you and members of your household. You must help yourself!

Ventilate to remove moisture

Ventilating rooms is a very important step to removing condensation and excess moisture.

• To ventilate a room, open the window slightly or use the trickle vent to allow warm moist air to escape to the outside and allow cool dry air into the property. You can ventilate a room without making draughts or causing it to become cold.
  • When using the kitchen/bathroom always ventilate by opening a window and/or using the extractor. You should also close any internal doors to prevent moist air spreading to other parts of your home. Continue to ventilate for a short period after use. Extractor fans are cheap to run, use less energy than a standard light bulb and can remove moist air quickly.
  • Open bedroom windows slightly for 20 to 60 minutes daily when you wake up and pull back bed sheets or duvets to air the bed and bedding.
  • Move furniture off external walls.
  • If you are having a bath, run the cold water first to reduce the amount of steam from the hot water. Keep the bathroom door closed.
  • Use a dehumidifier to help remove excess moisture from the air. These do not need to be electrical.
  • Smart Tip: Do not over-ventilate your home by leaving the windows open for a long period of time as your walls will lose all the heat stored in them. Open the windows for a short period at a time leaving a small gap of about 5 mm.

 Remember to close your windows for security when you go out.

Keep your home adequately heated

• Try to keep your home suitably heated. It usually helps to have a low background temperature of at least 15 degrees in all rooms. By doing this you are less likely to have condensation dampness as the warm air holds more moisture than cold. It will cost more initially to warm the walls, but when the walls are dry your heating bills will reduce.
• If you have an Economy 7 Night Storage Heater understand how to use it properly. Generally, night storage heaters have two knobs. The right one will control the heat input. The left hand one will control the heat output. To keep the room at a reasonable temperature you will need to adjust the heater to allow heat to escape gradually throughout the day. The control knobs are usually marked from numbers 1-10 around the outside of the dial. As a guide in mild weather (10-17°C) the input control should be between 4 and 8. In cold weather (10°C and below) turn the dial to 8 or above.
• Smart Tip: Do not put your heating on for short periods of time (one hour or less) as this will exacerbate the problem. The air will absorb moisture more quickly than the walls can warm up. When the heating is turned off the air will cool quickly, and condensation will form.

Reduce the amount of moisture

Everyday activities produce a lot of moisture. You can reduce this by:

• Covering pans when cooking, keeping the kitchen door shut and opening windows and/or putting the extractor fan on (remember to close your windows for security when you go out).
• Drying clothes outdoors if possible or drying clothes on an airer in the bathroom, with the door closed, the heating on and the window open and/or the extractor fan on. Avoid drying clothes on radiators. Over just 1 day, drying clothes in your home releases approximately 9 pints of water into the air.
• Venting tumble driers to the outside (not into your home). If possible, do not use them at all as this will also reduce costs.
• Not using paraffin or liquid petroleum (‘bottled’) gas heaters. They are very expensive to run and produce a lot of water vapour.
• Smart Tip: Do not over-crowd your home. The more people living in your home the more moisture will be produced which needs to be removed. One person during sleep adds half a pint of water to the air overnight and an active person emits twice that rate during the day.

Wipe away excess moisture and remove mould growth

Black mould growth in your home and on clothes, shoes and toys can be costly and may have a negative effect on your mental health.

• Wipe down the mould-affected areas using a fungicidal wash/soap or dish soap and water (always follow manufacturer’s instructions and wear protective gloves). This should kill and remove the visible mould.
• Wipe windows and windowsills every morning to remove condensation, paying particular attention to bedroom windows.
• Pull back bed sheets or duvets to air the bed and bedding.
• Smart Tip: Do not leave condensation or any water which has accumulated on windows, windowsills, walls or surfaces. Wipe the moisture off immediately.

If you are worried about your health or the health of other members of your household due to damp and mould in your home further guidance can be sought on the NHS website - Can damp and mould affect my health? - NHS (www.nhs.uk) and/or consult a medical professional such as your local GP and in non-emergencies 111. If it is an emergency contact 999.