Condensation is the water produced when moist air, vapour or steam meets a cold surface – such as windows, walls and floors and places with little air moving around. You can see it on bathroom mirrors when you bathe or shower. Black mould spots occur on damp surfaces where there is little movement of air due to poor ventilation.

Damp inside a property is either caused by structural defects (for example a leaking pipe), or by condensation. If damp is not caused by
a structural defect, then condensation is the issue, and the only lasting way to avoid severe mould is to reduce or eliminate the source of condensation.

Three steps to avoid condensation in your home

1. Produce less moisture Some ordinary daily activities produce a lot of moisture very quickly.

  • Cover pans and do not leave kettles boiling
  • Dry washing outdoors on a line if you can, or put it in the bathroom with the door closed and the window open or fan on.

2. Ventilate to remove moisture You can ventilate your home without causing draughts.

  • Keep a window ajar or a trickle ventilator open when possible.
  • Open kitchen and bathroom windows wider
  • Close kitchen and bathroom doors when these rooms are in use
  • Don’t put furniture directly next to external walls
  • Regularly wipe down surfaces such as windows which attract moisture.

3. Heating
You will get less condensation if you keep your home warm most of the time.

  • Insulation and draught proofing can help keep your home warm and cut fuel bills.

            – do not draught proof a room where there is a cooker or a fuel burning heater, like a gas fire
            – do not draught proof windows in the bathroom or kitchen.

  • In cold weather, keep low background heating on all day, even when no one is home. Most houses take quite a long time to warm up, and may cost more to heat it up quickly in the evening.

For more information
Download our condensation leaflet for a full list of tips on how to prevent and treat damp issues caused by condensation.

Contact us
If you are doing everything that you can to reduce condensation but still find that you are having issues related to damp and mould, then the issue may be something beyond your control – such as a fault in a property e.g. leaky roof, burst pipe or faulty damp-proof coursing.

If you think your home is damp and the cause is not condensation, please email our Customer Contact Team at or call us at 020 8080 6587 to arrange an inspection.