How to reduce damp and mould before winter arrives

Whilst your damp or mould issues may seem to disappear during summer, autumn is a good time to work out whether the cause is still there, before winter arrives.

Luckily, there are a few straightforward checks you can make yourself. They might uncover something obvious, such as an overflowing gutter or a blocked vent. Other problems need more investigation. Either way, painting over a damp patch or moving furniture to hide mould won’t deal with what is causing it.

Leaving damp and mould untreated can damage your home and affect your health. Persistent moisture can spoil plaster and decorations and, where timber stays damp, create conditions for decay. Mould can also affect your airways and lungs, so it’s worth investigating before the problem has time to grow.

In this article, we explore what you can check, what you might be able to put right, and when it’s worth getting an expert diagnosis.

Why does condensation get worse in winter?

When cold weather arrives, windows and external walls become colder too. Cooking, showering and drying clothes inside still produce moisture, but we’re often less willing to open windows and let it escape.

Nobody wants to lose the warmth they’ve paid for when it’s only a few degrees outside. However, without effective ventilation, that moisture can build up and settle on cold surfaces.

Condensation is just water vapour turning into liquid on a sufficiently cold surface, such as a window or wall. It sounds harmless enough, but when surfaces stay damp, they create suitable conditions for mould to grow.

Of course, condensation isn’t the only reason you might have damp. Water could be getting in through a roof defect, damaged guttering or a plumbing leak. Before you start trying to fix anything, you first need to understand where the moisture is coming from.

Start by checking outside

Before concentrating on the heating or windows, look at the parts of your home that keep rain out.

From ground level, check for:

• Gutters overflowing during rainfall.
• Dripping joints or disconnected downpipes.
• Broken, missing or dislodged roof tiles or slates.
• Water staining on external walls beneath guttering.
• Cracks or gaps in walls and around window openings.

Autumn leaves can obstruct gutters and downpipes. When that happens, water may spill against the building instead of draining away. Getting these checked and cleared before winter is a useful starting point.

You don’t need to climb onto the roof to make these initial checks. If something needs a closer look or work at height, arrange appropriate help.

If a damp patch inside becomes darker or larger after rain, take photographs and note when it happens. This can help someone inspecting your home understand the pattern.

Water entering through defects in roofs, walls or around openings is known as penetrating damp. A patch that changes after rainfall is a useful clue, but it isn’t enough on its own to confirm the cause.

Are your extractor fans doing their job?

Extractor fans in kitchens and bathrooms help remove moisture when you’re cooking or showering. It’s worth checking them before winter, particularly if steam seems to linger.

Whilst fans aren’t silent, unusual or excessive noise is a reason to have a look. Check that the grille is clear, and clean accessible parts according to the manufacturer’s instructions. If the fan is still unusually noisy or doesn’t seem to be removing moisture effectively, arrange for it to be checked.

You should never cover an extractor grille to keep the warmth in. Whilst it’s tempting to seal every gap, your home still needs a way to remove moisture.

Another simple check is whether your window trickle vents are open and unobstructed. These are the small, adjustable openings often found in window frames. They provide background ventilation without you having to leave the whole window open, so keep them open through winter.

If you’re replacing windows or improving insulation, discuss ventilation as part of the work. Keeping more heat inside is useful, but you still need to give moisture somewhere to go.

A few everyday changes can help

Use extraction when cooking and bathing

Switch on extraction when you’re producing steam. You should also close the kitchen or bathroom door to help stop that moisture spreading into adjoining rooms.

These are simple steps, but they work best alongside ventilation that is properly maintained and suited to the room.

Think about where you dry washing

Drying washing outside is useful when conditions allow. Of course, that isn’t always possible with the UK’s weather.

If you need to dry clothes indoors, use a suitably ventilated room with the door closed.

A dehumidifier can help collect moisture from the air. Just keep in mind that making clothes dry faster doesn’t mean the moisture has disappeared. It still needs to be collected or carried outside.

Cooking, showering and washing clothes are normal parts of living in a home. If mould keeps returning, it’s worth investigating whether the building and its ventilation are dealing with that moisture properly.

Check behind furniture and in cold corners

Take a look behind wardrobes, beside beds and in corners on external walls, especially if mould appeared there last winter.

If possible, leave some space for air to circulate rather than pushing furniture tightly against cold external walls.

Keeping your home adequately heated can help reduce condensation on cold surfaces. However, turning up the heating won’t repair a leak or fix an extractor that isn’t working.

A room can also feel warm whilst part of the wall is still cold. That cold patch may remain vulnerable to condensation, even when the temperature elsewhere feels comfortable. If one area stays noticeably colder than the surrounding wall, it’s worth finding out whether insulation or a construction detail needs investigating.

What if the mould keeps coming back?

Cleaning visible mould doesn’t remove the underlying source of moisture. If it repeatedly returns, spreads, or comes with persistent dampness or a musty smell, arrange an assessment.

Leaving the problem to grow can mean more damage to plaster, flooring, furniture and other belongings. Where moisture keeps timber wet, decay may develop too. What starts as a visible patch can therefore become a more involved repair if the cause remains unresolved.

Damp and mould can also affect your health, particularly your airways and lungs. Children, older people and those with certain existing health conditions can be more vulnerable. If you think damp or mould is affecting someone’s health, speak to a healthcare professional.

Larger areas of mould should be handled by appropriately qualified professionals. Avoid unnecessarily disturbing mouldy materials.

Housing providers have legal responsibilities too

If you rent your home, report damp and mould promptly to your landlord or managing agent, and keep photographs and a record of your report.

Landlords and housing providers have legal responsibilities to keep rented homes safe and meet repair standards. In England, Awaab’s Law also sets deadlines for social landlords to investigate and address serious damp and mould hazards. Different rules apply elsewhere in the UK.

Simply painting over mould or asking residents to keep wiping it away won’t fix the underlying problem. Reports need to be taken seriously, with the cause investigated and appropriate action taken.

When is it worth booking a damp survey?

If the cause isn’t clear, a patch changes after rain, or the same problem keeps returning, it’s worth getting it checked before it has more time to develop.

A useful survey should explain where the moisture is coming from and what needs to happen next. That gives you a clearer idea of the work needed before you spend money trying to fix it.

If you’re concerned about damp or mould in your Yorkshire home, book a damp survey with Allerton. Our team can investigate the cause and talk you through the next steps.