Help with mould growth

[clipperjay]

I would get thermal plaster board put in so you have two skin barrier then re plaster it it could be the pointing on the outer wall has seen better days?

[logeyboy]

I'd start with the obvious.
Check external wall pointing etc.
Check if there's any water running down it from gutters etc.
Rip the plaster off.
Fit a damp-proof course.
Re-plaster
Ventilate.

[salsheikh]

thanks for the advice fella's.

this is happening in my 1st floor bedroom. no ventilation bricks so no blocking of them
i will clean the area using dettol as you have mentioned and will fit air bricks/ventilation.
the pointing on the outside wall is fine and as its an old house it doesnt have cavity wall insulation.
the bed is against the wall due to it being a small bedroom with upvc glazing (trickle vents are open)
insulated plasterboard seems like a good idea. i might aswell do all 3 bedrooms that have an external wall but do it one at a time, costs isnt the issue, its moving the cupboards/moving stuff and drying time/repainting thats gonna be a PITA.

[hobbiniho]

the problem you have is condensation (you can see the run marks down the wall) not faulty pointing/leaking roofs as has been suggested if you had faulty pointing etc then it would not show in a perfect square behind your headboard it would show on the whole wall.
does the bedroom window often get condensation on it?? if it does you need better ventilation, do you have this problem in any other rooms in the house??

[mk2man1]

Hello mate have you sorted the problem yet, does this only happen winter time when its cold,do you wind the heating up high.Go up in the loft and check the underside of the roofing felt,see if you have water running down it towards were that mould is.

[jimmydub]

i'm thinking the problem is simply a cold external wall. mould will always grow on the coldest darkest spot. does it strictly collect behind the head board? or is it in the corners too?

as already said ventilation is key. pick yourself up a dehumidifier in the short term; have it on specifically at night, and if the humming keeps you awake put it in another room and leave your bedroom door open. speaking of which, do you sleep with the door open?

in the long term, insulation. baton the walls, use polystyrene sheets between the batons and then plaster board and re-skim. you'll lose a good 2-3 inches though if space is an issue.