She has in the past used neat bleach as I told her not to mix with water, I have also supplied her with Muffycid (http://www.markvitow.com/ENGLISH/produc ... %20Cleaner) and she has also tried mould & mildew sprays from supermarkets etc.

The house does have central heating yes, quite a new system too so it's efficient and is always warm in there.

There isn't wallpaper, it's plastered and painted so nothing to strip off and look at?

I've even tried an anti-condensation paint called bio-nature!

you need to know the door is kept shut that the window is open for about 40mins a day say 2pm to minimise heat loss and no washing is dried in that room
we also need to know that the tumble is working properly and not venting to the house
where is the tumble in relation to the damp room ??

is the bathroom door kept fully shut during use

is there any washing dried on radiators in rooms close to the damp room this includes any wet washing room dried by air

_________________
we are all ------------------still learning

The window is definitely open more than 40mins a day, everytime I drive past it is open, no matter what the weather. There is also an air brick in that room too.

The tumble drier is fairly is new (about 6 months) so it should be working properly although it is downstairs in the kitchen which is some distance from the bedroom (down the stairs, through the dining room to the kitchen, although there is only the bedroom door as a barrier). The kitchen has a humidity fan so it would kick in when if needed when the tumble drier was on, plus there is an extractor fan in the dining room too.

I am not sure about the bathroom door being shut when in use or towels being dried in that room but I will check, I wouldn't think the bathroom door was kept shut when in use as it's a small bathroom and she has 3 young children so I am guessing it would be cramped with all of them in there, but again there is a humidity fan in there and the kitchen which it comes off.

what people dont realise is iff the down stairs is open plan all the heat and moisture migrates up stairs as the upstairs will need to warm to about 4to 6 degrees above down stairs heat requirement before the heat stops

in other words your valves on you up stairs radiators can be set for say 17 degrees so they will shut off
down stairs will be set for say 21 degrees but until you heat upstairs to say 26 degrees giving you about 21 down stairs the heating wont stop

you will now have all the warm moist air in the house reaching a room with cold walls and condensing

_________________
we are all ------------------still learning

Good point, the radiators don't have temp valves on them so you can't regulate the heat upstairs and down unfortunately, mind you, being open plan and nothing to stop the heat travelling upstairs probably doesn't help either as you can't stop hot air rising.

Has anyone ever tried one of the condensation control units in the loft space and found it to be beneficial?

i would forget any expenditure at the minuet until you have worked out the cause
a dehumidifier in the bedroom may help
but you need to find the cause /causes for the problem before you can apply the solution

_________________
we are all ------------------still learning

I have tried a dehumidifier and it wasn't doing a lot, although it is only a small one from Argos.

I think the problem has to be severe condensation, I cannot see what else it can be really?

yes i agree but it looks like something else is "aggravating " the situation

_________________
we are all ------------------still learning

I've struggled to understand why certain areas get damp and promote the growth of mould. I've got a cold external wall (solid brick, no cavity) that gets the occasional mould growth which I remove quite easily with the anti-fungal spray you get from Tesco. The wall is cold to the touch but not as cold as my ceramic toilet cistern which is in the same area. However, the cistern never suffers with condensation.....it is always as dry as a bone. My windows also feel colder than the wall but never mist-up. We're told to heat and ventilate but when you're trying to keep the house warm whilst watching the energy bills it does seem a futile exercise. If all else fails just blame the dog (if you've got one)

Hi, I am a mould eradication specialist, before you continue to make yourself bankrupt with all these ideas of what the reason of the cause may be, have you considered that you may of bought the property with this mould growth problem, and that it was merely cleaned up painted and not correctly treated? therefore it will always remain untill you have the problem sorted. the main mistake people make is that it doesn't matter how many airbricks you have neither does it matter how much insulation you put into the property unless the mould is killed it will always remain, I don't want to spam at all and I have given good free advice on this excellent forum before, if you care to contact me I will sort this problem once and for all and you will not got round in circles with your purse getting lighter, your tenant needs this sorted asap as this sort of mould/damp issue can be detrimental to her and her childrens health.