How to get rid of mould, and keep it away

To get rid of mould, clean small patches on hard surfaces with a mould-killing spray, then dry the area. That's the easy half. The mould will come back unless you deal with the moisture that let it grow, which in most homes means condensation. Fix that, and the cleaning finally sticks.

Why mould grows in the first place

Mould needs a surface that stays damp for long enough. In most Scottish homes the damp comes from the air inside. Cooking, showering, drying clothes and simply breathing all put water into the air, and when that air meets a cold wall, window or ceiling, it turns back into water. That's condensation, and it's behind most of the mould people find at home.

Less often, the water comes from somewhere else: rain getting in through a blocked gutter or cracked render, a leaking pipe, a failed shower seal, or ground moisture rising up an old wall. Those need repairs, not just better habits. Working out which one you have is the most useful thing you can do before you spend money.

How to clean a small patch safely

Small patches on hard surfaces, like painted walls, window frames and tiles, are usually fine to tackle yourself.

1. Open a window or run the extractor fan, and keep it going while you work.
2. Wear rubber gloves. Some people also wear a mask and goggles.
3. Spray a mould-killing product on the patch and leave it for the time on the label.
4. Wipe it off with a damp cloth, working gently. Don't dry-brush or scrape, which spreads the mould around the room.
5. Dry the surface fully, then put the cloth in a bag and bin it, or wash it on a hot cycle.

Soft things are harder. Mould grows into fabric, carpet, sealant and wallpaper, and it often can't be cleaned out of them. Our guides on mould on clothes and curtains and mould in the shower cover the two most common cases.

What not to do

• Don't rely on bleach on porous surfaces. On plaster, wood or sealant it can take the colour out without dealing with the growth.
• Don't paint over it. Paint over live mould and it shows through again. Clean, dry and fix the cause first.
• Don't seal up the room. Taping over trickle vents or blocking air bricks to stop draughts makes condensation worse.
• Don't just keep cleaning. If the same patch is back within weeks, the moisture is still there.

Why it keeps coming back

Cleaning removes what you can see. It doesn't change the air in the room or the temperature of the wall. Official guidance for landlords in England says plainly that simply removing surface mould won't stop the damp and mould coming back. If the wall is still cold and the air is still wet, new mould settles in the same place, often within a few weeks in winter.

What to do this week

• Run the extractor fan or open a window while you cook and shower, and for a while afterwards.
• Dry washing outside, or in one room with the door shut and the window open.
• Pull furniture a few centimetres off outside walls.
• Keep rooms at a steady warmth rather than heating hard and letting them go cold.
• Open trickle vents and keep them clear of curtains.
• Wipe condensation off windows each morning.

A dehumidifier can help a damp room dry out, but it works alongside these changes, not instead of them.

Find the guide for your problem

• Black mould on walls
• Mould on a bathroom ceiling
• Mould in the shower and on silicone
• Condensation on windows
• Mould in the bedroom
• Mould behind a wardrobe
• Mould on clothes and curtains
• Mould in the loft

When it's more than condensation

Condensation mould sits on cold surfaces, in corners and behind furniture, and gets worse in winter. Other causes look different:

• A tide mark or crumbling plaster low on a wall can point to rising damp.
• A patch that spreads after heavy rain suggests water getting in from outside.
• A stain with clear edges near a pipe, a bath or a ceiling below a bathroom is often a leak.

Cleaning won't help with any of these until the water is stopped. A damp and mould survey tells you which one you're dealing with.

Your health

The NHS asthma causes page lists mould among the things people can be allergic to that can set off asthma. Government guidance written for landlords in England, Damp and mould: understanding and addressing the health risks for rented housing providers (MHCLG, DHSC and UKHSA), says everyone is vulnerable to the health effects of damp and mould. If anyone at home has asthma or a mould allergy, don't put off dealing with it, and speak to your GP if their breathing gets worse.

When to get a specialist

Call in a specialist if the mould covers a large area, has got into plaster, keeps coming back after you've changed your habits, or comes with signs of a leak or rising damp. A good one cleans the mould and fixes the cause, so you're not paying for the same job twice. Typical costs are in our mould removal cost guide, and our mould removal page explains what the work involves. Tell us what's happening and we'll pass it to one independent local specialist to quote. It's free to ask.

Last checked 26 October 2026. This is general guidance, not legal or building advice.