More People, More Moisture: How to Ventilate a Busy Family Home

Damp in a family home is far more common than most people realise, and it usually comes down to one thing: moisture. Every person in a house adds water to the air. We respire, bathe in it, boil it in the kettle, and hang it on the radiator with the washing. Add a couple of children, a load of washing or two a day, and a pan of water on the stove for dinner, and a family house produces a lot of it.

That moisture has to go somewhere. If it can't get out, it settles on the coldest surfaces as condensation, and over time that turns into damp patches and mould.

Are Family Homes More Likely to Have Damp?

Yes, and the numbers are pretty clear. A YouGov survey of 2,039 UK adults in 2025 found that the more people live in a home, the more likely it is to have mould or damp:

Homes with children were around 50% more likely to report damp than homes without (30% compared with 20%).

Don't be too hard on yourself if your house is on that list. More people means more moisture, and usually less spare space to dry things.

Where Does All the Moisture Come From?

Laundry

School uniforms, PE kits, bedding, and towels add up fast. When there's no tumble dryer, or the weather won't play ball, it all ends up on airers and radiators.

The survey found that people who open windows to help dry clothes indoors were more likely to have damp (30% compared with 21%). That suggests the washing is often putting more water into the room than the open window is taking out.

Bathrooms

Several baths and showers a day, often back to back, mean the bathroom rarely gets the chance to dry out. Half of the people in the survey who described their mould said it was in the bathroom.

Bedrooms

Children's rooms tend to be small, with the door shut at night and sometimes two children sharing. That's a lot of breathing in a small space for 10 or 12 hours, and 45% of people who described their mould mentioned a bedroom.

Kitchens

Cooking for a family means more cooking, more steam, and more moisture. About a quarter of the cooker hoods in the survey simply recirculate the air back into the kitchen. That deals with smells, but not the steam.

How to Ventilate Each Room

Children's Bedrooms

• Keep the trickle vents open all year. If there aren't any, this is the first room to add them to. An RW Simon Premium Trickle Slot Vent is cost-effective and takes about 15 to 20 minutes to fit.
• Air the room in the morning. Open the window wide for 5 to 10 minutes while everyone's getting ready, then shut it.
• Pull furniture a few centimetres away from outside walls so air can move behind beds and wardrobes. Cold corners behind furniture are a favourite spot for mould.
• Keep drying clothes out of bedrooms, especially overnight.
• Check the window seals. A damaged gasket can let rain reach the frame and make a cold, damp spot worse. Our Seal Centre helps you find the right replacement.

Worried about leaving a window open in a child's room? A trickle vent lets air in while the window stays shut and locked. Learn how: our guide to childproofing bedroom windows and doors covers restrictors and locking handles too.

Bathroom

• Run the extractor fan during and after every shower, and leave it on for a while. If yours comes on with the light, leave the light on for a few minutes afterwards.
• Keep the door shut while you shower so the steam doesn't drift through the house, then open the window or vent to clear it.
• Squeegee or wipe down the shower screen and tiles after the last shower of the morning.
• Keep the trickle vent open, if the bathroom window has one.

Laundry

• Dry clothes outside whenever you can, even for a few hours.
• Pick one room for drying indoors, ideally one with a trickle vent or extractor fan. Keep the door shut and the vent open, so the moisture heads outside rather than around the house.
• Avoid draping wet clothes on radiators. Radiators push moisture into the room quickly and make the heating work harder, costing you more money.
• Run a dehumidifier in the drying room if you have one.

Kitchen

• Put lids on pans and switch the cooker hood on whenever you're cooking.
• Check what your cooker hood does. If it recirculates rather than venting outside, open the window or trickle vent while you cook.
• For a busy kitchen, the RW Simon Trickle Vent Hi-Flow+ 525mm lets more air through than a standard vent.

The 10-Minute Family Ventilation Routine

Here's what to do each day:

• Morning: open bedroom windows wide for 5 to 10 minutes while everyone's up and about.
• After showers: extractor fan on and bathroom door shut, then open the window for a few minutes.
• Laundry day: dry in one room only, with the door shut and the vent open.
• While cooking: lids on, hood on.
• All day: trickle vents open in every room that has them.
• Evening: wipe any condensation off the windows before bed so it doesn't soak into the frames.

Can You Keep a Family Home Warm and Dry?

You can. The trick is to stop the cold air you don't want and let in the fresh air you do.

Start by sealing the draughts. Worn window and door seals let cold air in all around the edges, and replacing them is one of the cheapest jobs in the house. Then ventilate on purpose with trickle vents, which give you a small, steady flow of fresh air without opening the window.

If you've already replaced your seals, find out why you might need a trickle vent after replacing your window seals. If you're wondering whether to shut your vents when it gets cold, read our blog should trickle vents be open or closed in winter?

Shop Trickle Vents with GB DIY

Have a browse through our full trickle vents range, with standard, Hi-Flow+, and acoustic options, all with same-day dispatch on orders before 3 pm.

We're here to help. Send a photo of your window through our Part Finder, by WhatsApp or email, and we'll help you work out which vent or seal you need. Or give us a ring on 01623 622205.

FAQs

Why does my child's bedroom have condensation every morning?

Because a closed bedroom fills up with moisture from breathing overnight, and it settles on the coldest surface, usually the window. Keep the trickle vent open, air the room each morning, and avoid drying clothes in there.

Is it OK to dry clothes indoors?

It's fine now and then, but it adds a lot of moisture to the air. Dry them in one well-ventilated room with the door shut, rather than spread around the house, and keep the trickle vent open.

Will trickle vents make my child's room cold?

They shouldn't. They let in a small amount of air high up, where it mixes with warmer air. If the room feels cold, check the window seals for draughts first, using our winter window draught guide.

How do I stop mould growing behind furniture?

Move wardrobes, beds, and chests of drawers a few centimetres away from outside walls so air can circulate behind them. Keep the room ventilated, and check behind furniture every few months.