Mould, Condensation and High Humidity in rental flat

LP0008

Hi everyone looking for two bits of advice really - 1. how to tackle the issues ourselves and 2. how to approach getting it sorted with the landlord. 

We live in a 2nd floor flat, it is relatively modern, however the building is an old office block. The original windows are still present, but the refurbishment of the building into flats put double glazed windows in addition (so we have the old single glazed windows, a gap, and then the newer double glazed windows inside the flat). 
Our heating and hot water system has been having issues for the last few months - and I am mentioning this in case anyone thinks it might be contributing to the issue. 

At the start of winter we noticed almost immediately that there was condensation around the plastic window frames of the internal windows, and lots of condensation on the old single glazed window pains. The condensation was to the point that it was dropping down the windows. 
We have opened windows, however there is only so much we can open them and being on a main road it is not ideal to have them open for long periods of the day. 

Our heating is through the old office heating in the ceiling and the temperature of our flat has never dropped below 18/19 so we tend to not have the heating on - it averages at about 20 degrees C most days. 

We have now seen black mould growing in the space between the two windows and also around the internal window frames on the plastic. 

I recently bought a dehumidifier, and it is saying our humidity levels are about 70%RH. 

The property managers so far have sent someone round about the heating/ hot water but it has not been resolved. They have not directly addressed our repeated emails about the condensation and the mould - the boiler engineer said the windows seemed secure and he can't work out why it's happening. I have been told by another tenant that they are also getting the condensation issues. 

Any ideas on how I can stop the condensation / or what I can do to get the landlord to look into it properly? 

MattMattMattUK

Generally indoor humidity and condensation is caused by occupants. They key questions are, when you shower do you always have the extractor fan running, or has this been turned off? When you cook, do you use the extractor fan? How do you dry clothes?

Typhoon2000

Condensation indoors means high humidity. You don’t need to switch on the heating because the flat is well insulated. So you need to increase ventilation/use a dehumidifier/use a drier rather than air dry washing. How many of you are there and how big is the flat. Lots of people in a smaller place will lead to higher humidity.

tacpot12

RH of 70% is very wet - my bathroom fan comes on automatically when the RH is that high. It should be down around 50%. You need to trace where the moisture is coming from. Drying clothes, cooking and showering are the usual suspects. Do you have extractor fans in the bathroom and kitchen and do they operate automatically? Do either set of windows have vents in them? 

housebuyer143

Most people need to wipe down the windows everyday or they get mould from the condensation, so start doing that. Condensation on bedroom windows is very normal.

Sometimes you can't do anything other than what you are and use the dehumidifier. My old house became about 70% humidity and that was because we had a baby and just got more water vapour in the house from breathing etc. We would use the dehumidifier everyday reducing it down to 60% and it would turn off. Solved all our issues. 

LP0008

Thanks for all the response @housebuyer143 @tacpot12 @Typhoon2000 @MattMattMattUK

To update / answer some of the questions:
our shower room doesn’t have a window or an extractor fan, it has ceiling ventilation which we recently asked to be cleaned as it wasn’t functioning well. 

We use the extractor fan when we cook. 

We do have to dry clothes on a rack as we do not have a dryer. 

There’s two of us in the flat and it is fairly spacious a high ceilings etc. 
No vents in the windows. 

The windows are almost floor to ceiling so they cover a huge area. I know that condensation on window glass is quite common but it’s the condensation on the plastic window frame which concerns me - it can sometimes be there the entire day. 

The level of condensation and mould between the outer and inner window also concerns me because I cannot understand how that much moisture is coming between the two windows. 

The worst area is a section where the outer window doesn’t even open so I’m not sure how I would resolve. I don’t know if you can see from the image below: 

Probably also worth noting that this is our second year here and we didn’t have these issues last winter.  

MattMattMattUK

LP0008 said:

Thanks for all the response @housebuyer143 @tacpot12 @Typhoon2000 @MattMattMattUK

To update / answer some of the questions:
our shower room doesn’t have a window or an extractor fan, it has ceiling ventilation which we recently asked to be cleaned as it wasn’t functioning well. 

We use the extractor fan when we cook. 

We do have to dry clothes on a rack as we do not have a dryer. 

There’s two of us in the flat and it is fairly spacious a high ceilings etc. 
No vents in the windows. 

The windows are almost floor to ceiling so they cover a huge area. I know that condensation on window glass is quite common but it’s the condensation on the plastic window frame which concerns me - it can sometimes be there the entire day. 

The level of condensation and mould between the outer and inner window also concerns me because I cannot understand how that much moisture is coming between the two windows. 

The worst area is a section where the outer window doesn’t even open so I’m not sure how I would resolve. I don’t know if you can see from the image below: 

Probably also worth noting that this is our second year here and we didn’t have these issues last winter.  

Does the extractor vent externally, or does it just filter the air and add it back into circulation? 

With poor bathroom ventilation, drying clothes indoors and some/all moisture from cooking you are adding a significant amount of moisture into the property, a single load of washing could be several litres. I think in your circumstances you need to get a dehumidifier otherwise you will continue to have problems. 

sevenhills

LP0008 said:

our shower room doesn’t have a window or an extractor fan, it has ceiling ventilation which we recently asked to be cleaned as it wasn’t functioning well. 

Surely it must have one or the other?

Just openable vents then?

Albermarle

Probably also worth noting that this is our second year here and we didn’t have these issues last winter. 

There are a lot of recent threads on here about condensation problems. Not sure if there are more than other years, but it seems a problem that is widespread. Suppliers of humidifiers can not keep up with orders. Although humidifiers do seem to be the 'must have' household appliance of the moment, and have probably benefitted from lost of media coverage including on MSE.

MattMattMattUK

Albermarle said:

Probably also worth noting that this is our second year here and we didn’t have these issues last winter. 

There are a lot of recent threads on here about condensation problems. Not sure if there are more than other years, but it seems a problem that is widespread. Suppliers of humidifiers can not keep up with orders. Although humidifiers do seem to be the 'must have' household appliance of the moment, and have probably benefitted from lost of media coverage including on MSE.

Hopefully dehumidifiers otherwise things are going to go very wrong!

This winter has been colder than last so I suspect that is having an impact, we also seem to have had more intense rain at periods (not more, it has just come in lumps) and I think people are still energy conscious, especially not getting the free money this winter that will have focused some people's minds more, where as last winter they might have seen the increased cost as a one winter only thing and so decided to find the money to keep temperatures up indoors. That and a full year of the fabric of the building absorbing moisture might mean that it is now saturated. 

LP0008

sevenhills said:

LP0008 said:

our shower room doesn’t have a window or an extractor fan, it has ceiling ventilation which we recently asked to be cleaned as it wasn’t functioning well. 

Surely it must have one or the other?

Just openable vents then?

We have this in the ceiling which I assume is a ventilator - there is no off and on switch for this so I assume it is supposed to work constantly. We recently had it cleaned as we had clumps of dust falling from it as I suspect it was clogged and had never been cleared. 

There is no other ventilation in the bathroom.