Damp and mould

Did you know that having a bath or shower can produce two pints of condensation? And two people simply being at home for the day can produce around three pints?

How you can prevent damp and mould in your home

Understanding what causes damp and mould can help to get rid of it and stop it from coming back.
Many people confuse a home with a condensation problem as one with ‘damp’.
The good thing is you can normally do quite a lot yourself to solve the problems caused by condensation. But it can be harder to cure structural damp.
Below are some of the reasons damp and mould happen in your home and some tips on what you can do to avoid them. 

Structural damp

This is what rising damp normally looks like


This is what condensation normally looks like

Structural damp explained

  • Rising damp is caused by ground water moving up through a wall or floor. Damp-proof protective material (sometimes called a ‘course’ or ‘membrane’) usually stops the water from causing damage
  • Penetrating damp is caused by leaking water. It’s usually caused by structural problems in a building, such as faulty guttering, or it can be caused by internal leaks, like pipes under the sink. This type of damp may expand across walls or a ceiling horizontally 


Condensation explained

Condensation happens when warm moist air meets a cold surface, like a window or an outside wall


  • It’s normally caused by the everyday things we do in our homes which cause moisture in the air

  • It mainly happens when:
  1. We don’t open our windows often enough to let the warm moist air out (when we’re cooking or taking a bath, for example)
  2. A home is not heated properly
  3. When the extractor fan is missing or not working
  • It’s found:
  1. Above windows, on the ceiling or the outside walls of a home
  2. In places where there’s not a lot of air flow – such as behind furniture
  3. The spores can spread to internal walls and furniture

Here are some great tips on how you can avoid condensation and mould from happening in your home:

  • Don’t overfill your cupboards
  • Leave space between the furniture and walls
  • Open your windows when you can to let the moisture out
  • If you have vents in your walls or windows, make sure they’re open
  • Dry your washing outdoors
  • If you have to dry it indoors, don’t hang it on the radiators. Use a clothes horse in the bathroom with the extractor fan on and the window open
  • Open the windows to let the moisture out if you’re drying clothes indoors
  • If you use a tumble dryer, make sure the ventilation pipe leads outside. If it’s a condensing tumble dryer, you still need to open a window to let the moisture out
  • Use the extractor fans in your kitchen and bathroom
  • Keep a lid on sauce pans to reduce heat (this can also save you money as you can cook on a lower heat setting)
  • When filling your bath, run the cold water first then add the hot water – this will reduce the steam, which leads to condensation, by as much as 90%
  • While in the bath or shower, keep the door closed to stop the moist air getting all around your home - when you finish, open the window for 10 minutes or so to let the moist air out
  • Don’t over-heat or under-heat your home. Use a hygrometer to measure temperature and humidity. This will help you keep your home at the right temperature
  • Don’t heat your home to a high temperature very quickly as it makes condensation worse. It’s also expensive
  • A stable temperature is better than a swinging one. Between 18-21 degrees, with a humidity of 40-60% is best
  • Wipe down windows and window-sills when they get wet or you see condensation
  • Wipe down surfaces with a mould cleaner (always follow the manufacturer’s instructions)
  • When you’re decorating use an anti-mould paint in areas where you’ve had problems (area must be completely clear of mould first)
  • Don’t brush or hoover the mould as this can spread the number of spores in the air

If your mould is really bad and you can’t get rid of it

Step 1 – Tell us more

  • We’ll need to find out the type of mould it is and what might be causing it. Once we know this we can work out how to fix the problem.
  • Tell us all about it by reporting the problem here
  • We’ll send you an advice pack with a questionnaire to return. It’ll be really helpful if you also included some photos. We’ll ask you to monitor this for four weeks
  • It’ll also give you advice on how to heat your home and reduce the amount of moisture in the air
  • If you’ve followed our advice and you've still got a problem, you can ask for a step two survey


Step 2 – Doing more investigations

  • A repairs supervisor will look at the photos and questionnaire and contact you to decide what to do next
  • If we think the problems are caused by the building, we’ll arrange for them to be fixed
  • We’ll write to you to confirm what we're going to do 
  • You should continue to follow the 'What to do if I have a problem with mould?' advice from step one (or on other parts of this web page)
  • We’ll give you a call six weeks after any repair work has been done to see if this has solved the issue


Step 3 – Looking at it again

  • If you’ve still got a problem, we’ll visit you at your home and do a full survey
  • We’ll let you know what we plan to do next
  • We’ll offer you advice if we think there are some things you can do to help
  • You should continue to follow the 'What to do if I have a problem with mould?' advice from step one (or on other parts of this web page)
  • We’ll call you four weeks after any repair work has been done to see if this has solved the problem


Step 4 – If you’ve still got a problem despite doing all the right things

  • We'll ask an independent expert (a surveyor) to visit your home and report back to us
  • We’ll ask them to tell us what they find, what they suggest is causing the problem and what can be done to solve it 
  • There may be a charge to you if the survey finds it’s a condensation issue
  • We’ll write to you and tell you what the survey says and what we’ll do next
  • If they find something that we missed when we came to see you, we’ll tell you we’re sorry and we’ll put it right


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