Damp on bedroom wall

[diystuey]

the little bedroom in my house was decorated a year ago and now the wallpaper in the corner of the two external walls is mouldy and damp.

This might not have been helped by longish curtains on the window and the position of a chest of drawers, giving little opportunity for air to circulate in this corner.

However i moved the drawers a few weeks ago hoping this would be enough to stop the problem and allow the area to dry out.
It hasn't dried out though.

I am wondering whether to move the central heating radiator from its current location to the mouldy corner. Is this a good idea? Would it stop the damp wall problem happening?

See the image for details:

Untitled

• diystuey
• 11 Nov 2011
• 1

 

[Richard C]

You have either a damp penetration problem or condensation; if it’s happening behind furniture or curtains it may be damp penetration Moving the radiator won't cure it, you need to establish what’s causing it.

How old is the property? What type of external walls do you have, solid or cavity? Do you have modern double glazing? Do you at least have background heat in the room or have you shut the radiator down & close the door? Do you dry washing in the house? Do you ever ventilate the room? Do you have extractor fans in the bath/kitchen/utility rooms? Have you checked nearby guttering isn’t leaking or windows letting water in?

 

[diystuey]

the property is a 1930s brick built semi-detached.
Not too sure about the walls, probably is cavity wall. Double glazed windows throughout the house, the house is central heated, i have just had a new boiler fitted. Most of the washing goes in an externally vented tumble drier, only a few bits get dried on the downstairs rads.

I guess the room ventilation could be better - i'll start opening the window in there for an hour on a morning.
We have a hob extractor in the kitchen and a humidistat controlled fan in the bathroom.

Haven't checked the guttering - the window isn't leaking though.

The chest of drawers were previously in the proposed new rad position. with the curtains from the window dropping to about 6 inches above the skirting board, which is what made me think it could be condensation. If this is the case, wouldn't putting the radiator on the exposed external corner eliminate the condensation?

 

[foxhole]

A radiator has no effect on condensation and therefor mold.
The room should have a permanent vent.

 

[Richard C]

the property is a 1930s brick built semi-detached.
Not too sure about the walls, probably is cavity wall.

Well it could be a significant factor so you need to confirm. Cavity walls were generally used post 1932; check here
http://www.west-norfolk.gov.uk/default.aspx?page=22397

Double glazed windows throughout the house, the house is central heated, i have just had a new boiler fitted.

Modern double glazing is very efficient at hermetically sealing the house & you must ensure adequate ventilation/extraction to let moisture from cooking, bathing, breathing, sweating & drying washing escape or it will just condense on the coolest surfaces it can find once it reaches dew point. Do you have trickle vents fitted to the windows? Do you leave them open? If not consider retrofitted vents.

Most of the washing goes in an externally vented tumble drier, only a few bits get dried on the downstairs rads.

Well you need to stop doing that; moisture from drying washing doesn’t just magically disappear, it evaporates & increases internal humidity levels. Without adequate ventilation to disperse, it will find it’s way to the coolest parts of the property & cause condensation; possibly on the North wall of a, poorly heated, unventilated bedroom!

I guess the room ventilation could be better - i'll start opening the window in there for an hour on a morning.

Does anyone sleep in there, if so it’s best to have it open slightly during the night; it’s also healthier for you. We exhale a considerable amount of moisture &, again, if this can’t escape through natural ventilation it will condense on the coolest surfaces when dew point is reached. The window in my bedroom is open 12 months of the year!

Haven't checked the guttering

You should check eaves, guttering, roof tiles etc. thoroughly for any water ingress.

The chest of drawers were previously in the proposed new rad position. with the curtains from the window dropping to about 6 inches above the skirting board, which is what made me think it could be condensation. If this is the case, wouldn't putting the radiator on the exposed external corner eliminate the condensation?

As has already been stated, moving the radiator won’t cure condensation, it will merely shift it somewhere else. You need to reduce the ambient humidity of the air inside the room/house which is being caused either by lack of ventilation or damp ingress.