Help! High humidity/Mould in ground floor council flat (UK)

Mama_H

This is my 1st post - unsure from the categories whether this is the correct one but couldn’t find another category for housing issues advice (let me know of there’s a certain category used for this please!)

I live in a council flat, ground floor, built in 1977. I got some humidity hygrometers that track temperature + humidity levels and send the data to my phone, they track constantly and save data up to 1 year.

During the winter/spring, the humidity levels aren’t high (Oct-March) however I do use the central heating most during these months. Am aware warm air holds more water, however I must note that even before the heating is turned on the humidity is not high. It stays within 39-49 range - towards the lower end when heating is on.

I open the windows every day other than when it is raining and wet, because this would be counterproductive for humidity.

However during the late spring/summer/autumn (April-late Sept) the humidity levels are high. They’re between 55-65, opening the windows makes barely any difference and never goes below 55. 

I never dry washing on radiators, I don’t have a tumble dryer spouting out warm air, I don’t hang washing to dry indoors other than in the kitchen with a dehumidifier on with the door closed and the levels are kept low when dehumidifier is on (takes it down from 60-45/50 within an hour). As I said I open windows everyday to ventilate other than when wet with doors open to create a ‘wind tunnel’ type of draft however the levels don’t go very low. The more into the summer the worse it is. 

I recently discovered that the walls here are cavity walls, however there are no weep vents or any type of ‘space’ to allow moisture to leave the cavity. The council are absolutely useless and despite me complaining for over a year, they insist the humidity is caused by me. I am going to bring up the cavity wall/weep vents to them, however as it takes weeks for a response i’d like some advice on here in the mean time!

could anyone confirm whether cavity walls should have weep vents? Is there an exception where they’re not needed? I’m sure what’s happening is warm air/moisture is being trapped in the cavity wall and as it has nowhere to escape and warm air is attracted to cold areas - my flat is colder than outdoors due to concrete floors/ground floor flat/nobody below me/no underfloor heating/no insulation in cavity walls however it’s kept between 19/22 degrees - and thats why the moisture is only an issue in the summer, and not during the wet winter.. 

thanks.

Mama_H

Should add - I have laminate flooring, now with a vapour barrier underlay which I re-did as i was worried the humidity was caused by the floors. Previously did have underlay but not the vapour barrier kind. This didn’t solve the issue so have ruled that out. Mould had started to grow on furniture - none was pushed up against outside walls, and none were pushed up against inside walls either.. there’s gaps. The mould was growing at the bottom upwards + not at the top of anything. Really want to get this sorted as it cost hundreds to replace and I can’t afford to replace it all again!

theartfullodger

Raise the matter, calm and polite, with council (you are tenant or owner? ) through their complaints process, very likely documented on council website .

Which country -Scotland, Wales...?  Understand it's UK but there are 4 different legal and tenancy systems...

breaking_free

I don't think your humidity levels are particularly high at all (the summer/winter levels in my home are higher than yours and I have no mould problems).

From this website “The average humidity inside UK homes should be around the 50-55%rh range and be slightly lower in winter months”. 

I'm not suggesting you don't have a problem, I'm just asking why you believe your humidty levels are excessive. Happy to be corrected by yourself or other forumites.

_Penny_Dreadful

Mama_H said:

This is my 1st post - unsure from the categories whether this is the correct one but couldn’t find another category for housing issues advice (let me know of there’s a certain category used for this please!)

I live in a council flat, ground floor, built in 1977. I got some humidity hygrometers that track temperature + humidity levels and send the data to my phone, they track constantly and save data up to 1 year.

During the winter/spring, the humidity levels aren’t high (Oct-March) however I do use the central heating most during these months. Am aware warm air holds more water, however I must note that even before the heating is turned on the humidity is not high. It stays within 39-49 range - towards the lower end when heating is on.

I open the windows every day other than when it is raining and wet, because this would be counterproductive for humidity.

However during the late spring/summer/autumn (April-late Sept) the humidity levels are high. They’re between 55-65, opening the windows makes barely any difference and never goes below 55. 

I never dry washing on radiators, I don’t have a tumble dryer spouting out warm air, I don’t hang washing to dry indoors other than in the kitchen with a dehumidifier on with the door closed and the levels are kept low when dehumidifier is on (takes it down from 60-45/50 within an hour). As I said I open windows everyday to ventilate other than when wet with doors open to create a ‘wind tunnel’ type of draft however the levels don’t go very low. The more into the summer the worse it is. 

I recently discovered that the walls here are cavity walls, however there are no weep vents or any type of ‘space’ to allow moisture to leave the cavity. The council are absolutely useless and despite me complaining for over a year, they insist the humidity is caused by me. I am going to bring up the cavity wall/weep vents to them, however as it takes weeks for a response i’d like some advice on here in the mean time!

could anyone confirm whether cavity walls should have weep vents? Is there an exception where they’re not needed? I’m sure what’s happening is warm air/moisture is being trapped in the cavity wall and as it has nowhere to escape and warm air is attracted to cold areas - my flat is colder than outdoors due to concrete floors/ground floor flat/nobody below me/no underfloor heating/no insulation in cavity walls however it’s kept between 19/22 degrees - and thats why the moisture is only an issue in the summer, and not during the wet winter.. 

thanks.

Those aren't high humidity readings.  I run a dehumidifier when I have to dry my laundry indoors and the dehumidifier is working to reduce the humidity to 55%.  However you are living your life it does not appear to be in a way that causes excess humidity as shown by your hygrometers.

Where is the mould growing?

Mama_H

Sorry, shouldve added more info. I’m in east of england, UK.

the levels that i’ve said (55/60%) are only managed with dehumidifier.. i cant seem to keep them to this level even with windows open/ventilation. If i do anything in any room, even sleep (which i know 1 adult can create up to 2 pints of water p/night) this puts the levels up far higher over 60% which creates mould growth and dust mites thrive - then opening the windows doesnt lower it. Anything further i do inside for example say dry my hair with a hairdryer is expected to raise the humidity a bit but as the ‘base level’ humidity is already at the highest end, it sends them too far. These 40-55% levels of humidity being normal are based on lived in conditions provided ventilation is being done and I am but my levels won’t stay this acceptable level, dehumidifiers are expensive to run and i really cant afford to run them for hours every day. Even after getting the levels down to 40%, then turning off and everyone being out of the house they are back up to 58/60% within a few hours - nobody and nothing is left making that moisture (no washing being left out, no pets, no wet towels, no standing water etc).

Had not any mould growth happened, i’d not be worried about these levels.. but mould does grow at these levels here in this flat. Might be different in a house or a less-old property, i’m really not sure.

Does anyone have an answer to the weep holes in cavity walls? 

Mama_H

Also / the humidity in rooms such as kitchen/bathroom get much higher - 80%+ when cooking or bathing but that is understandable and I am not worried about that as its clearly being created and with windows open it goes down to 60%. But like i said this level of 60% is still too high to be a ‘baseline’ temp. If i close windows after airing out any room, the levels creep up - even with nobody home. Thanks for all the replies so far, hard to describe a situation fully on here isnt it hahah i’m trying my best!

Mama_H

Mould isnt growing on walls, but paint is flaking off around the windows - they’re double glazing PVC windows - so i’m sure it’s just a matter of time before that starts again.. however there isnt any condensation on the windows causing this or any mould on the windows or rubbery bits themselves. Even if there was, this would be clear in winter when its cold outside so the warm air from inside would hit the glass and create the condensation. This issue of flaky paint - and mould growing on the bottom of furniture - is in the summer months. Thanks

Mama_H

Here’s some photos of the flaking paint around windows. However the windows themselves are mould free. There are also trickle vents in the windows. Thanks.

Mama_H

Photo 2: window paint.

Mama_H

Last year, wet patches began to show up on the walls which are the ones that are external. I’m sure this will repeat this year, as the levels continue to creep up. We are only in may and these levels peak in July/August when it’s hottest. This is mild.. i know the worst is coming so maybe it might look as though i’m over reacting at these levels but this is just the beginning!