Condensation running down bedroom wall & dehumidifier not helping

JustKeepSwimming_2

I have a condensation problem in my small (8' x 8') upstairs bedroom which I just can't get rid of.

I noticed it 2 years ago when I saw lots of furry black mould growing all up the corner walls to about 1' & all the way along the skirting. Not sure how long it had been there as it was hidden by a double bed that couldn't be moved. I cleaned it all off & got rid of the bed, now just have a futon & nothing touching either external wall & it went away during the summer. This winter it is back - the wall is wet all the time from skirting up to 4' & it appears within minutes of wiping it down. The house is a semi, ex-council house probably thrown up in the 70's, concrete block construction.

I've been advised not to get cavity wall insulation as there is likely to be lots of debris in the cavity & this could make damp problems worse.

I've tried turning off the heating & keeping the door closed to see if that helps (mighty chilly when I go in to sleep). I've tried having the heating on all day & running a dehumidifier - this is collecting water, but not as much as I'd expect & the walls are still wet. I don't think its a problem with the dehumidifier as it worked brilliantly to dry out my kitchen when it got flooded a few weeks ago. (it's all fun & games here just now!)

There aren't any other patches of condensation - not on the (old) d/g window in the same bedroom (& I always thought windows would be colder than walls so this is where the condensation should form?), on the same walls downstairs (hallway) or anywhere else. My tumble drier is in a utility room at the other end of the house, I shower with the bathroom window open & the door shut, I ventilate the house as my cat is forever going in & out & I usually sleep with the bedroom window open (just not now as I'm not that hard, but it is opened as soon as I'm up for a good 10-30 mins). I've tried pulling back the carpet & using the gale that runs through the floorboards as extra ventilation - makes no difference.

I had new guttering/downpipes 2 years ago, along with a new membrane for the roof as was told that the problem may have been damp due to a misplaced ridge tile which may have caused water to get into the cavity. Surely this would have dried out over 2 summers if this was the problem & why would only upstairs be affected,not downstairs? My loft is fully boarded & I can't see any signs of damp/condensation up there.

I've read up on how condensation forms & tried all the advice - it just feels like nothing has worked & I'm stumped. Any ideas anyone? Thanks.

gratefulforhelp_2

Difficult one. I have had this problem with water running down sitting room walls, fixed by...

better heating, on low all the time
extractor fans in kitch and bath
dehumidifer in kitchen

the problem is the moisture content of the air versus the temperature, so anything that will drop the humidity levels (e.g. do you boil things with lids on the pans) or increase the temp will help.

Good luck!

Jake'sGran

How long have you lived there? Did you have a survey done? I feel that the problem must have existed before you moved in and I expect it will be expensive to put right.

If you have buildings insurance I don't think this kind of problem is covered. Sorry to sound so negative but this problem would really upset me. If you did have a survey done and were given the all clear for major problems you may have recourse to whoever provided it. I would also have a word with the local council, just to get their
opinion, and they may have grants for this kind of thing.

Finally, it's not good for you to sleep in a room as damp as your bedroom. If there are spores in the damp it could affect your health.

Swipe

What temperature is the room when you are running the dehumidifier? Most compressor types are ineffective below around 12C. Try running the dehumidifier with the heating on in that bedroom and see if it collects more water. However, at the end of the day, you still need to discover the root cause of the problem.

JustKeepSwimming_2

Jake'sGran wrote: »

How long have you lived there? Did you have a survey done? I feel that the problem must have existed before you moved in and I expect it will be expensive to put right.

I did have a survey done (& went round with the surveyor) but as there was a large desk in the corner of that room he couldn't get to the walls to see & the walls he could get to were fine - so I'm sure the problem did exist before & was covered up by the previous owners :mad: - no comeback on the surveyor though.

If you have buildings insurance I don't think this kind of problem is covered. Sorry to sound so negative but this problem would really upset me. If you did have a survey done and were given the all clear for major problems you may have recourse to whoever provided it. I would also have a word with the local council, just to get their
opinion, and they may have grants for this kind of thing.

Many of the houses are owned by a housing association & their buildings department told me that only 1 of their stock has had cavity wall insulation - has caused problems in that house. A damp company came round & told me there was no damp, & I could get the walls internally insulated. To me this just covers up the problem & will make an already small room much smaller.

Finally, it's not good for you to sleep in a room as damp as your bedroom. If there are spores in the damp it could affect your health.

Forever cleaning with mould killer! Thankful I don't have asthma or any other respiratory problems (yet)

JustKeepSwimming_2

Swipe wrote: »

What temperature is the room when you are running the dehumidifier? Most compressor types are ineffective below around 12C. Try running the dehumidifier with the heating on in that bedroom and see if it collects more water. However, at the end of the day, you still need to discover the root cause of the problem.

Thanks - I didn't know about the minimum temperature. I've cranked the heating up & will see if that helps.

Can't imagine where all this water is coming from though. Kitchen windows don't steam up if I'm cooking as I have an extractor fan running, lids on all pots (this is MSE after all)....

Busybody

do you have the window open in that room at all? it may help to clear the room of moisture!

alanobrien

There is something very odd going on here. Sounds like the dehumidifier isnt working or isnt big enough to cope with the load. Have you cleaned the dehumidifier filter lately ? My experience is that a properly sized one will resolve any condensation problem.

The main issue of course is lack of ventilation, but i know open vents/windows and winter dont go well together.

If the walls are streaming you may want to consider lining them with a polystyrene liner then papering over. That would help to reduce the differential temperature on the surface and thus minimise condensation.

You may also want to consider replacing the dehumidifier and/or having one for upstairs and one for downstairs. If so go for a dessicant model such as this one as they are efficient down to freezing whereas compressor versions only work well above 5c.

http://www.energybulbs.co.uk/products/Energy+Saving+Products/Dehumidifiers/ECOAIR+DD122FW+SIMPLE+Desiccant+Dehumidifier+%28DD122%29/2944267352

gratefulforhelp_2

Def no damp patches on outer walls?

About dehumidifiers, we have an ebac one and it is ace, their customer service is fab. Cost around £200 though.

ddoris

What type heating? Keep heat on , room window open and door closed.

Get some builders/roofers/damp firms in for quotes and note what they say.

Jake'sGran

I just remembered comething else that can cause a damp problem. If you have a garden and there is soil in the beds close to the house walls it must be below the damp course. Hope you know what I mean.

I do believe this problem is more serious than anything that could be remedied by using a dehumidifier. Hope it does get sorted soon.