Living in the UK: Why Mould Happens and How to Reduce Indoor Humidity

Living in the UK means dealing with damp weather and the common problem of mould in homes. The mild but wet climate, combined with older housing styles and limited ventilation, creates the perfect conditions for mould to grow. Understanding why mould appears and how to control indoor humidity can help keep your home healthier and more comfortable.

Why Mould Happens in UK Homes

The UK’s climate plays a big role in mould growth. Winters are usually mild but wet, and humidity levels often stay high throughout the year. When warm, moist air inside the house touches cold surfaces like walls or windows, condensation forms. This moisture creates an ideal environment for mould spores to settle and grow.

Older homes are especially vulnerable. Many have single-brick walls that don’t insulate well, allowing cold to seep inside. Heating systems in older houses may not distribute warmth evenly, leaving some areas cooler and damper. Limited ventilation traps moisture indoors, increasing humidity levels.

Common sources of indoor moisture include:

• Cooking without lids or extractor fans

• Drying clothes indoors

• Bathing or showering without proper ventilation

• Houseplants releasing moisture

• Breathing and everyday activities adding humidity

  
  

When this moisture builds up, it collects on cold surfaces and in corners, leading to visible mould patches and sometimes a musty smell.

How to Identify Mould Early

Spotting mould early helps prevent damage and health issues. Look for:

• Black, green, or grey patches on walls, ceilings, or window frames

• Peeling paint or wallpaper

• Musty or damp smells in rooms

• Allergic reactions like sneezing or coughing when indoors

  
  

Mould often appears in bathrooms, kitchens, behind furniture, or near windows where condensation collects. Regularly check these areas, especially during colder months.

Practical Ways to Reduce Indoor Humidity

Controlling indoor humidity is the best way to stop mould from growing. Controlling indoor humidity is the most effective way to prevent mould from developing. To understand what’s happening in your space, it helps to monitor the humidity levels in your room. You don’t need anything expensive for this, a small digital hygrometer is more than enough.

I’ve found this simple under-£10 option useful. It shows both temperature and humidity, and can connect to an app so you can check levels even when you’re not at home.

Once you know whether humidity is an issue in your home, you can start improving the situation through ventilation and daily habits. Here are some effective steps:

Improve Ventilation

• Use extractor fans in kitchens and bathrooms during and after cooking or showering.

• Open windows regularly to let fresh air circulate, even in winter.

• Consider installing trickle vents or air bricks if your home lacks proper airflow.

  
  

Manage Moisture Sources

• Cover pots when cooking to reduce steam.

• Avoid drying clothes indoors; use a dryer or dry outside when possible.

• Use dehumidifiers in damp rooms to pull moisture from the air.

• Limit the number of houseplants in small rooms.

  
  

Keep Your Home Warm

• Maintain a consistent temperature to prevent cold surfaces where condensation forms.

• Use radiator panels or reflective foil behind radiators to improve heat distribution.

• Insulate walls and windows to reduce cold spots.

  
  

Regular Maintenance

• Fix leaks in plumbing or roofs promptly.

• Clean gutters to prevent water damage.

• Repair damaged window seals to stop drafts and moisture entry.

  
  

When to Seek Professional Help

If the mould has only just appeared

Mould buildup along bathroom tiles

Cleaning supplies used for removing mould.

If the mould is new and limited to a small area, you can often remove it yourself. The location matters. Most small patches appear in bathrooms, around windows, or in corners with poor ventilation.

For light, early-stage mould, two of the most effective sprays in the UK are HG Mould Spray and Cillit Bang Black Mould. Just keep in mind that mould-removal products have a strong chemical smell. The safest option is to use them before you leave home for a day or two. By the time you return, the smell will have faded, and the black spots should be gone. If needed, repeat the process once more.

I personally use HG Mould Spray and the HG Grout Cleaner for cleaning the gaps between tiles - both work very well for small bathroom areas and are not expensive.

For larger patches, spreading mould, or stains that return quickly, it’s best to contact a specialist. Your health and your home are worth protecting ❤️

If mould covers large areas or returns despite your efforts, it may indicate deeper issues like structural damp or poor insulation. In these cases, consult a professional surveyor or damp specialist. They can assess your home and recommend solutions such as:

• Installing damp-proof membranes

• Improving insulation

• Upgrading heating systems

  
  

Addressing the root cause will protect your home and health in the long term.

Health Considerations

Mould can trigger allergies, asthma, and respiratory problems, especially in children, elderly people, or those with weakened immune systems. Reducing indoor humidity and mould growth improves air quality and overall wellbeing.

If you experience persistent symptoms linked to mould exposure, speak to a healthcare professional. Remember, this article provides general advice and does not replace medical consultation.