Cheap flatpack wardrobe fitted close to but not touching exterior insulated cavity wall.
The hardboard backing sheet has some discolouration due to mould although the wall is unblemished.
If this was in a barn, I would slap on some Cuprinol 5* or some such. Is there an effective product for interior (bedroom) use.
I have yet to be disappointed with HG mould spray. Obviously chlorine-based from the smell, but it seems to keep mould away for a lot longer than simple bleach, so I suspect it contains more than just bleach.
More to the point, there has to be spores coming from somewhere and why is the back getting wet?
Bleach?
Brian
Line outside back of wardrobe with expanded polystyrene tiles or polystyrene insulating lining paper.
Presumably, there's a source of moisture in the room?
Not necessarily. In the far SW, where I live, the humidity is always high because of proximity to the sea and the predominant wind being SW. Black mould will grow on walls and other surfaces where there is little or no air movement, such as behind cupboards, wardrobes, mirrors, pictures etc. without there being a specific source of moisture in the room.
Connected. It's a granny annexe but used for the last 2 years by the son of some friends. No tumble drier so any clothes air dried. Ventilation/opening windows seems a foreign language. We did give him a dehumidifier.
Anyway, he has moved in with 2 friends so we a just sorting out the issues.
>In message , Chris Hogg writes
Hmm.. may be a down side to underfloor heating where there is little air circulation due to minimal convection.
>In message , Chris Hogg writes
OK. I'll pass that on to the domestic management dept.:-)
>In message , Peter Parry writes
Interesting. I suppose I could encourage a bit more air movement by moving it forward of the skirting as well.
No liquid product is going to stop condensation. You must have RH very close to dew point for this to happen with CWI. Reduce RH.
NT
That's the wrong reason. You need thermal insulation between the wall and the back of the wardrobe, and there must be no air gap between the wall and the thermal insulation (doesn't matter about between the insulation and the wardrobe).
I would buy an 8x4 sheet of 25mm celotex/kingspan or equivalent. Fix it to the wall behind the wardrobe, making sure any gap around the edge is filled so it's air-tight against the wall (or condensation will form behind it and run out the bottom).
Also, avoid piling any fabric against the rear of the wardrobe, as it will form an addition layer of porous insulation and risk getting damp at the back.
This will prevent the rear of the wardrobe dropping below the dew point in the room, and suffering from condensation.
The other options are move the wardrobe so it's not against an outside wall, or get the outside wall insulated.
It's already insulated. More is going to make minimal difference. It's time to address the cause & get RH down.
NT
In message , snipped-for-privacy@gmail.com writes
I think attaching insulation to the wardrobe back can't do any harm and can easily be sold to the boss:-) I think she would now prefer to junk it and go for a clothes hanging rack.
It is possible that partly dried clothes will have been hung in what is virtually an airtight space.
There is no convenient place for a tumble drier unless I stick one in the bedroom.
Female residents would open windows!
It can. Apart from being work unlikely to succeed it can trap condensation, worsening mould.
NT
Worked every time I've done it. Polystyrene insulation is closed cell so it can't "trap" condensation. The problem isn't water dripping from walls but warm air cooling as it gets between the colder wall and warmer wardrobe. This creates a slight film of condensation which is enough to allow mould growth either on the wall or the wardrobe. You commonly see this occurring in a room used to dry clothes or a North/East facing corner of a room which tends to be cooler than others. If clothes are dried in the room the answer is to get a proper dehumidifier in the room and run it while clothes are drying and for a time afterwards (It also speeds up the clothes drying).
on uninsulated walls or insulated?
Like any plastic, polystyrene foam is vapour permeable. Currently condensation can evaporate readily.
indeed
Yes, or other measures that also reduce RH. Some people for example seem to have no idea how to cook without creating masses of water vapour and wasted gas.
NT
Like almost all plastics polystyrene foam is not permeable
Both, the problem the OP described is common and is caused by the environment around the back of the wardrobe where there is reduced air circulation and a marginal drop in temperature. Normally the amounts of condensation are small and just enough to allow localised mould growth.
His proposed solution of removing the wardrobe and hanging clothes on a rail may be ineffective as the clothes, if resting against the wall, will create the same conditions and allow the same mould growth he is seeing on the wardrobe but on the clothes instead.
Polystyrene allows about 2% of vapour to pass which is why even a thin layer such as polystyrene "wallpaper" on the wardrobe is enough to solve the localised problem. If the present condensation could evaporate readily the mould wouldn't grow. As it is it can't, condensation is forming not in large amounts but enough to create a sufficiently damp local environment for mould to flourish. Quite probably there will be no patent water noticeable on either the wall or wardrobe.
I agree that poor ventilation in many houses, especially those retrofitted with double glazed windows combined with a lack of understanding about damp is a problem.
I was surprised that the OP mentioned that there is mould on the wardrobe, but not on the wall. Any explanations?
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