Controlling condensation and mould in your home

This page gives helpful advice on how to treat condensation in the home.

What causes condensation?

There are three main causes of condensation:

1. Moisture produced by everyday activities
2. Not enough ventilation 
3. Cool temperatures

Cooking, drying clothes, showering – even breathing – add to the moisture in the air. If this moisture is allowed to build up, it can cause damp. It can increase the risk of respiratory illness and cause black mould growth on walls, ceilings, furniture and clothing. 

This mould growth is often caused by condensation from everyday activities. Some people mistakenly think these are signs of damp caused by problems with the property itself. 

How much moisture can be produced in your home in a day?

• two people active for one day = 3 pints
• cooking and boiling a kettle = 6 pints
• having a bath or shower = 2 pints 
• washing clothes = 1 pint
• drying clothes = 9 pints
• using a paraffin or bottled gas heater = 3 pints

Three main ways to deal with the problem

Stop moisture from building up 

• wipe down surfaces where moisture settles
• cover boiling pans when cooking 
• cover fish tanks to stop the water from evaporating into the air 
• dry clothes outside where possible 
• vent tumble dryers to the outside 
• avoid using bottled gas or paraffin heaters as these produce a lot of moisture and can also be a health and safety risk if not used and stored properly 

Also, close kitchen and bathroom doors to prevent steam from entering colder rooms when you have finished:

• cooking
• bathing 
• washing and drying clothes

Ventilate or air the home

• when cooking or washing, open windows or use extractors 
• if you have to dry clothes indoors, do so in a small room with windows open 
• open windows for a while each day or use the trickle or night vents
• do not block air vents – this is also important where gas and heating appliances are concerned as they need a supply of oxygen to work effectively and allow gases, such as carbon monoxide, to escape

Also, allow air to circulate furniture and in cupboards by:

• not overfilling cupboards and wardrobes 
• placing space between the furniture and the wall

Keep your home warm 

Draught-proofing

It will keep your home warmer – and help reduce fuel bills. When the whole house is warmer, condensation is less likely to form. 

Insulating your loft

Insulating your loft and walls will help. If yours need to be insulated, please ask your landlord to visit Norfolk Warm Homes or email energy@north-norfolk.gov.uk for advice on energy efficiency and grants. 

Maintain a low heat when the weather is cold and wet

It is more effective than short bursts of high heat.

Important things to remember

Do not block:

• permanent ventilators
• chimney openings

Do not draught-proof rooms where there is:

• condensation or mould growth 
• a gas cooker, or a fuel-burning heater, for example, a gas fire 

Do not:

• draught-proof windows in the bathroom or kitchen 
• put furniture against cold external walls

If your home already has mould 

The above tips should help prevent mould, but what if you already have the problem? How do you get rid of it? 

Do not disturb mould by brushing or vacuum cleaning. It can increase the risk of respiratory problems. 

Mould is a living organism and needs killing to get rid of it. To do this:

• wipe down affected areas with a fungicidal wash that carries a health and safety executive approved number – making sure you follow the manufacturer’s instructions
• do not use bleach or washing up liquid
• treat any mould you have in your home, then do what you can to reduce condensation - it will restrict new mould growth
• mildewed clothes should be dry cleaned, and any affected carpets shampooed
• after treatment, redecorate using a good quality fungicidal paint to help prevent mould from recurring - this paint is not effective if overlaid with ordinary paints or wallpaper

What happens next?

If you have followed the advice, you should notice a considerable improvement within a few weeks (around four to six weeks). If the problem continues, it may be due to another cause of damp. 

Condensation 

Follow the advice given on this page.

Rising damp

Rising damp is rare because a damp-proof course prevents it. However, it shows as a tide mark above the skirting board.

Penetrating damp 

Caused by a problem with the fabric of the building, which means rainwater can get through the walls, roof, windows or doors.

Plumbing faults or broken leaking pipes 

Rising damp and penetrating damp can usually be easily identified at the early stages. A leaking pipe can be more challenging to locate. If you suspect you have a leaking pipe, you should report this to your landlord as soon as possible.

North Norfolk District Council thanks Broadland Housing Association for permission to adapt their content.