How to stop condensation in your home

Condensation stops when moisture is removed at source and the house has steady background ventilation. In practice that means extract fans that work, ducted outside, in every kitchen and bathroom, plus trickle vents or a whole-home system such as PIV.

Where does the moisture come from?

Showers, baths, cooking, kettles, drying clothes indoors and breathing all add water to the air, often several litres a day for a family.

Why do windows stream in the morning?

Overnight, bedrooms fill with moisture from breathing while windows are the coldest surface, so water condenses on the glass and frames.

What should I check first?

Test your extract fans: hold a sheet of toilet paper to the grille and see if it is held. Check whether the fan ducts outside rather than into the loft.

What fixes work best?

Working, correctly sized fans in wet rooms; trickle vents open; and, where condensation is widespread, PIV or continuous extract. MVHR suits airtight homes.

When is it not condensation?

Damp that appears after rain, tide marks low on walls or patches near leaks point to penetrating or rising damp or a plumbing leak, which need a different fix.

Sources

• NHS, can damp and mould affect my health?
• BEAMA guidance on Part F for dwellings in England

Related services

Condensation and mould ventilation fixes

We find why the house is wet and fix the ventilation, rather than painting over mould.

From £445 inc VAT per fan

Positive input ventilation (PIV)

Loft or wall units that gently push filtered air into the home to tackle condensation.

From £795 inc VAT per home