Excessive humidity (90 percent) and mould, landlord is not solving

Hi, I am having the worst experience. 3 weeks ago, we moved into a 2 bed flat. The humidity in the bedrooms are quite extreme, sometimes it is 90 percent, on average it is 80 percent humidity. For the rest of the flat, humidity is not an issue(usually around 45 percent), as the living room and kitchen have new windows but the bedroom windows are quite old. We can literally feel the drift close by the windows.

The day we moved in, we saw some moulds in the windows and it is growing. My health has been affected, as I have been having shortness of breath and difficulty breathing. My husband also has been affected badly due to the extreme humidity and condensation. To fix the issue:

  • We purchased a dehumidifier and it is running 12 hours per day but not solving the problem
  • We ventilate bedrooms for at least 2 hours and we wipe the windows daily, as they usually are covered with extreme condensation every day.
  • We did our best to keep the rooms heated but even after setting the temperature to 26 degrees in the living room (which is extremely hot), the bedrooms are around 20.5 degrees, at least 5 degrees less than the living room. The heater is working fine, we even kept the blinds and curtains closed but due to the poor insulation of the windows, we are experiencing a significant loss of heat.
  • a lesser worry, but we can hear everything from the street as if the windows are open. The noise level is disturbing us, as the bedrooms are facing a slightly busy road.

I have talked to my landlord a few times, but he kept saying that he used to live in the flat and he did not have an issue or the other tenants. He kept saying he won’t change the windows, but our health is seriously affected, I am not able to sleep in the bedroom. He also said we should buy a buy bigger dehumidifier. I really do not want to use the dehumidifier 24 hours, as this is noisy, let alone it would increase our electricity consumption significantly. So he is diverting the issue instead of solving it. It is a terrible situation and we have just started our tenancy (1-year contract), I would really prefer to move to another property if I can. Any sort of advice is hugely appreciated.

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is this a ground floor flat Sounds very damp. . I do not think just new windows will solve this What is the EPC ?

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A lot of difference in humidity is due to different temperatures in each room. Condensation forms is coldest room, ie the bedrooms. I’d suggest trying to keep a constant 20 degrees in each room which should even it up more. Doesn’t need to be 26!

Also minimise moisture let off into property so after showers ensure bathroom door shut a window left open for 30 mins and use lids on cooking pans on hob etc. If you dry washing inside run the dehumidifier while it is drying but not with windows open as they don’t work with windows open as they would be dehumidifying the world and failing…

This is worst time of year for humidity/Condensation so it should improve over time.

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The EPC is D, this is the ground flat but we have garages underneath. The other rooms have new windows and we have normal humidity. Really do not know what else we can do:(

thanks for the advice. We actually stop using the ensuite bathroom due to this issue. I have dimmed down the radiator in the living room, to keep the temperature constant, but in the bedrooms even though the radiators are working full power, the heat is barely around 21. We also applied your suggestions already but it is still quite humid.

Our landlord is approaching this as if this is not his responsibility but this is seriously affecting our health. If I can leave now, I will, even though it is really costly and tiresome.

There is probably no insulation between you and the garage. . as Richard says Do not dry clothes in the flat . Is there an extractor fan in the bathroom? Dryers also give out moisture. Steam from cooking , Extractor in the kitchen? D is quite a good EPC

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About the garages, I have talked to other neighbours, no one except us has the humidity issues. There are extractor fans in the bathrooms but maybe is not strong enough. I also use dehumidifier in the bathrooms too, as there are some mould growing inside them.

We never dry clothes inside the flat, we have a tumble dryer. We barely cook things, so I feel desperate as I did everything possible, so the only possible reasons are poor window insulation or some leakage.

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the other flats probably have full double glazing ?

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Yes, they have double glazing windows and the only one having extreme humidity is us, so this brings up the main issue is with windows. But my landlord is acting quite stubborn and he told me this is an old flat and we knew it before moving in, but we never knew that humidity was that extreme. He refused to take any responsibilities on this end.

try local council who will give advice and have the equipement to measure the effects.

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thanks for all the suggestions, really appreciate it. My worry about the council, it will take some time for them to assess the situation and make a decision, at the same time, I am not able to sleep in my bed. Are there any solutions to speed up the process or help me to nullify the existing contract? I am quite worried about our health.

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nothing worse than sleeping in a damp room. You could tell the landlord that you are seeking help from the council…That may gee him up… Temp job , seal up the window with putty , can be easily removed, downside ,no fresh air


The window can’t be the reason, it must be something else. The moisture must come from somewhere and it can’t be ambient air only, there must be some pipes leaking or something like that.

I can keep my window 1" open all the time and humidity won’t go above 50 this time of year (22C inside). As an experiment you can open your window in the living room to the extent you think the old window is leaking air, say 1/2", you’ll see that the humidity there will never go even over 70, let alone 90. Or you can emulate the new window by sealing your bedroom’s window with masking tape. You’ll see that the humidity will not go down, most likely it would go up if anything.

Anyway you have to establish the cause first and fight over the solution then. Otherwise it’s just a guessing game and I can see why the landlord is not keen.

That being said 90% is unacceptable and I would involve the council immediately. Relative humidity is inversely proportional to temperature, so you could use an additional electric heater in your bedroom as a temporary measure to save your health in the meantime.

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thanks! I actually tested it, when we left the windows open in the bedrooms for 2 two hours, the humidity was decreasing around 62 %, but it is also quite dependant on the outside humidity. there must be some other factors for this, but as far as I can see, the windows do not have proper insulation. We did our best to keep bedrooms heated, but even the radiator is open all the time (such an energy loss), we barely see 21. Also, I cannot notice whether the windows are closed or not, because I can hear everything from the street as if it is open. That is why our first guess is the windows, but we are not professionals, the landlord should look into the issue, there might be another reason such as leakage. The main problem, he is behaving as if this should be tolerated and it is not his responsibility.

Thanks a lot for all the help, it is really frustrating to deal with this situation while our health is the main concern. He might try revenge eviction?

eviction will take some time if you refuse to leave.

You need to call in the environmental health officer to inspect the property. Yes, it may take a little while, but they can help establish the cause of the problem or put pressure on your landlord to do so. In the meantime you need to keep the windows in the bedroom partly open during the daytime to reduce the humidity. You can get an anti-mold spray from Poundland for ÂŁ1 to kill the mold growth.


If you want to leave then him evicting you would be in your favour wouldn’t it?
He doesn’t sound a lthe best landlord in the world.

If you can hear everything from the street then you need to get the window seals replaced if they’re fitted with rubber seals as they perish over time.
Also upvc windows can be adjusted

There is a chronic shortage of rental properties in many parts of the country and if you’re in such an area, it may prove difficult to secure another property and there is no guarantee that you will find a trouble-free one. If I were you, I would work out how much it would cost you to move again. You may discover that the cost of moving again may actually be the same as the cost of replacing the bedroom windows yourself. I’m sure your landlord would be more than happy to let you do that. Just a thought.