The Mould Prevention Strategy That Works Versus the One That Wastes Money

Why wiping condensation off windows every morning means you're treating symptoms, not causes.

The Mould Problem

You’re wiping condensation from windows every morning, noticing dark spots appearing in bedroom corners, and wondering whether that musty smell is just “normal for winter.” Someone suggests buying a dehumidifier, so you spend £200 on a device that runs constantly… while the mould keeps returning.

Why?
Because you’ve treated the symptoms, not the causes.

Mould thrives when three conditions align: moisture, warmth and poor ventilation. Remove any one of these, and mould cannot grow. Properties that stay mould-free through winter aren’t necessarily new or perfectly insulated — they’re homes where occupants understand and control the conditions mould relies on.

Ventilation Matters More Than Heating

Ventilation is the single most effective mould-prevention tool — and the one most people underuse.

Opening windows for ten minutes every morning, even in winter, expels moisture-laden air before it condenses on cold surfaces. It feels counterintuitive when you’re trying to keep heat in, but those ten minutes do more to prevent mould than running the heating all day with the windows sealed.

Moisture generation is heaviest in kitchens and bathrooms:

• Showers, baths and cooking release litres of water into the air

• Extractor fans should run during use and for at least twenty minutes afterwards

• If no extractor fan exists, open the window immediately after bathing or cooking — even if it’s freezing

And always close internal doors while cooking or showering. That steam doesn’t disappear; it migrates to colder rooms where it condenses on windows, walls and in corners — exactly where mould takes hold.

Temperature Consistency Prevents Condensation

Mould doesn’t simply thrive in warmth — it thrives when warm, moist air meets a cold surface.

Heating one room intensely while leaving others cold creates the dramatic temperature variation that drives condensation. Maintaining a steady, moderate temperature throughout your home is far more effective than overheating certain spaces.

Common problem zones include:

• Cold corners

• External walls

• Areas behind wardrobes, sofas and large furniture

Pulling furniture 10cm away from external walls can significantly reduce hidden condensation build-ups. That small gap allows air to circulate and prevents stagnant cold patches where mould forms unnoticed.

The Cleaning Approach

Cleaning visible mould with fungicidal sprays helps temporarily — but cleaning doesn’t prevent recurrence.

If ventilation, heating consistency and moisture control aren’t addressed, mould will return no matter how aggressively you scrub.

However, persistent or spreading mould despite proper prevention often signals a deeper issue, such as:

• Inadequate insulation

• Failed damp-proof courses

• Leaking gutters or roofing

• Structural defects allowing water ingress

These are landlord or property-owner responsibilities, not unavoidable winter realities.

If you suspect structural causes, document everything:

• Take dated photos

• Keep a log of when and where mould appears

• Report concerns formally in writing

Persistent damp and mould are health hazards and evidence of maintenance failure.

Your Mould Prevention Strategy

To create a mould-resistant home this winter:

• Ventilate every room daily for at least ten minutes

• Use extractor fans during and after cooking or showering

• Maintain consistent, moderate temperatures throughout the property

• Keep furniture slightly away from external walls

• Clean existing mould properly, then eliminate the conditions that caused it

Properties that remain mould-free aren’t lucky — they’re well-managed. Prevention isn’t about wiping windows every morning; it’s about controlling airflow, moisture and temperature so mould simply cannot take hold.

Struggling With Persistent Mould?

If you’re following these strategies and mould is still recurring, the issue may be structural. Document the problem and seek expert advice on whether your property requires professional intervention.

FAQ

1. Why do I get condensation on my windows every morning?
Because warm, moist indoor air meets a cold window surface and turns into water droplets — the first stage of mould growth.

2. Does heating stop mould?
Heating alone does not stop mould. You need consistent temperatures and ventilation to remove moisture.

3. Are dehumidifiers enough to stop mould?
Dehumidifiers reduce moisture but don’t address poor ventilation or cold surfaces. They help, but they won’t fix the root cause.

4. How long should I ventilate a room in winter?
Open windows for around 10 minutes daily, and use extractor fans during and after cooking or showering.

5. When is mould a landlord’s responsibility?
If mould persists despite correct ventilation and heating, structural issues may be the cause, and landlords are usually responsible for resolving them.