The information here is based on the Centre for Sustainable Energy’s easy read leaflet on dealing with damp, available here

Damp and mouldy are bad for your health and may make asthma and other health problems worse. Damp and mould can also damage your home. You may see mould that looks like a cloud of little black dots on your walls and ceilings, often in the bathroom or kitchen. It could also be in other rooms behind furniture, under beds or in wardrobes.

Damp can be caused by too much water or steam trapped in your house. It can also come from leaking roofs or damaged pipes – these can be fixed. There are things you can do to minimise damp– even small actions can really help.
1. Make sure there is less moist air around
• Keep the lids on your saucepans when you are cooking.
• Dry your clothes outdoors, or on a clothes airer in a bathroom with the window open. Do not dry them on a radiator.
• If your tumble dryer has a hose, make sure it is outside.
• Do not use paraffin heaters or bottled gas heaters.

2. Let the damp air out and the fresh air in
• Use the extractor fan in the bathroom or kitchen, if you have one – they are cheap to run
• Stop damp air getting into the rest of your home – keep kitchen and bathroom doors shut when you cook, or when you have a shower or bath
• Open the window while cooking or showering so that steam goes outside, not into your other rooms.
• If your windows have trickle vents fitted, keep them open.
• Make sure there is a gap between furniture and the walls. Air your wardrobes and cupboards sometimes by leaving the doors open.
• Open windows to give unused rooms an airing from time to time

3. Insulate and draught proof your home
• Warm homes are less likely to be damp. Make sure your loft and walls are insulated
• Make sure your windows and outside doors have draught proofing
• Change single glazed windows for double glazing
• Don’t block radiators with furniture
• Set any radiators to low in unused rooms if damp is a problem to avoid very low temperatures