Managing condensation and mould

What is condensation?

Air holds moisture, even when you cannot see it. When the air in your home holds too much water vapour, it will condense as moisture causing the air to feel damp.

Condensation mostly occurs where warm moist air hits cold surfaces such as around windows, cold external walls or areas with little to no air movement.

You may see small drops of water on walls or windows.

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Image caption: Image 1: Black mould on the walls in the corner of a room.

What is mould?

Mould is a type of fungus that grows and develops in damp or humid conditions and where condensation is present. Removing mould permanently is difficult and it will routinely recur mainly in Autumn and Winter. Microscopic spores are always present in the air and traditional housing means that cold walls allow them to grow, even if the heating is routinely on and the property is well ventilated throughout the year. 

When the humidity levels get too high, or where moisture is present in the structure of a building, mould and mildew growth becomes likely.

Mould will often present as small black spots covering an area.

Cold air holds less moisture than warm air. This means that there is an increased chance of condensation, mould and mildew growth in the colder months of the year.

What are we doing to resolve cases of damp and mould?

Hammersmith & Fulham Council are making a number of changes to how we manage damp and mould both strategically across the borough and at an individual property level, including:

  • Investing £600 million in buildings as part of our 12 year capital strategy.
  • Delivering a planned preventative maintenance programme to clear drainage stacks.
  • Completing a stock condition survey (including a Housing Health and Safety Rating System Assessment which assesses risks relating to damp and mould) of all our properties over the next two years.
  • Creating a dedicated damp and mould team to take your call and investigate.
  • New temporary measures to include a wall wash and provision of dehumidifiers to help manage issues in the short term.

How can I manage condensation and mould?

There are a few simple steps that can help you reduce condensation and mould in your home.

Produce less moisture

Moisture is released into the air through everyday activities such as cooking, washing, bathing, even breathing.

You can reduce this by:

  • covering pots and pans when cooking
  • pouring an inch of cold water in the bath before adding hot water
  • washing or replacing a shower curtain regularly
  • wiping down windows and sills and other surfaces where condensation forms on a regular basis
  • wringing out cloths rather than drying them on the radiator
  • drying laundry outside where possible.

If you need to dry laundry indoors, put it in the bathroom with the door closed and the window open or extractor fan on.

If you have a tumble dryer, ventilate it to the outside.

Ventilate to remove moisture

Tips for ventilating your home:

  • keep a small window ajar where safe to do so or putting on the window lock
  • ventilate kitchens and bathrooms when in use by opening the windows or using an extractor fan
  • close kitchen and bathroom doors when they are in use
  • avoid putting too many things in wardrobes and cupboards which will stop air circulating
  • avoid pushing furniture right up against walls so air cannot circulate around it
  • don’t block trickle or ventilation grilles and air bricks.

Insulate, draught proof and heat your home

In cold weather keep a low background heat on all day above 15 degrees.

Fit draught proofing to external doors and windows (not in the kitchen or bathroom).

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Image caption: Image 2: A dehumidifier

Mechanically remove moisture

Electrical dehumidifiers are electrical appliances that reduce and maintain the level of humidity in the air. They are excellent for removing moisture from the air and help with drying washing. The air filter needs to be cleaned weekly and water emptied daily. They cost around 23-30p an hour to run so are not cheap, but they are effective.

Disposable desiccant dehumidifiers such as calcium chloride and silica gel can absorb moisture but cannot be used for large spaces.

Dehumidifiers can be purchased from your local home improvement stores. Follow all instructions carefully.

How can I remove mould?

Vinegar

Vinegar is a mild acid which can kill 82% of mould species - it is natural, non-toxic and doesn’t give off dangerous fumes like bleach does.

Put white vinegar in a sprayer or bowl, wipe or spray on mould leave for an hour and then wipe down. This may need to be repeated regularly to reduce reappearance.

Baking Soda

Unlike other mould killers which contain harsh chemicals, baking soda is mild (pH of 8.1) and harmless to your family and any pets.

Add one quarter of a tablespoon of baking soda to a spray bottle of water. Wipe down the mouldy area with the baking soda and water solution. Scrub away the mould. This may need to be repeated. You can combine the vinegar and baking soda as an alternative. 

Bleach

If the mould is growing on non-porous materials such as tiles, baths, glass and countertops you can, if used safely, wipe them down with bleach and water solution.

Clothes and carpets

Dry-clean any mildewed clothes and shampoo carpets.

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

Reporting a problem

Council tenants

Contact our customer service centre if you continue to have issues with mould.

You can report your issue:

Our team will be happy to help.

Private rented property

For advice on reporting problems in private rented property see damp and mould in rented homes - Shelter England