Mould in corner of room.

[Rampage]

We have noticed mould in a corner of a room gradually getting worse:

It's a dormer bungalow, so the roof eaves are above this corner of this room. There is a room above this which effectively in the loft, this room has a dormer window. I've taken apart one of the fitted wardrobes and found a hidden door behind it, this led into an old cupboard and behind another wall was the crawlspace above the dampness and can't see anything damp/wet. The felt has holes in though.
After that I went onto the roof, but couldnt see any broken tiles or anything that could cause water to get in. I removed a tile, but saw no moisture inside the facia boards. The outside of the bricks that make up the inside cavity appeared to be dry.
There was a substance between the cavities that looked like icing sugar or potato starch? Is this some sort of insulation?

Any ideas on where the dampness is coming from? Could it just be condensation? I drilled a couple of holes in the facia boards to give it ventilation, as there are currently no vents.

Thanks,
Chris

 

[jeds]

Condensation. Very common in corners where the air does not circulate as well. Reduce moisture and increase ventilation.

 

[Rampage]

Ok, thanks.
I'll open the window more often!
Do I need to use anything to stop the mould speading?
Will spraying something that kills bacteria onto it help?

 

[jeds]

A mild solution of bleach in warm water will kill the mould as well as proprietary treatments. You can get mould resistant paints or an additive to put into ordinary paint but to be honest what you've got there is fairly mild and I would think cleaning with bleach and water would deal with it.

 

[Rampage]

Well, the mould came back after treating it.
Also, more water was appearing on it. The water has created a gap between the coving and the wall, also where the coving is joined it has cracked.

We had someone look at the roof who said the tiles were fine but the felt needed repairing. After this was done it was still the same. I looked at what he had done and he'd put a piece of felt under the bottom 2 tiles on top of the original felt. Just pushed under the wooden tile support, running down to the gutter.
I had a spare day so had most of the tiles off this side of the roof. I re-felted from about 3/4 up the roof to the bottom a couple of sheets wide, extending the felt way into the neighbours roof.
But it's still leaking, any idea's?[/img]

 

[ChapiTheBricky]

to get rid of the unsightly surface mould, buy some Miltons sterilising fluid, the stuff they used to use to clean babies bottles back in the day. Get an old spray bottle(the kind used for domestic cleaning), fill about an 8th of this with the miltons, about a 16th of bleach and about a 16th of water.
spray a fine mist of this onto the mould and leave for an hour or so then wipe off with a DRY cloth, repeat this process until the surface mould is gone.
Keep room well ventilated and keep an eye on how long this takes to come back, anything less than two weeks and i would say you had a pretty big problem and it's time to call in the experts to investigate where the ingress of water is coming from.

 

[Rampage]

We're pretty sure it's not condensation due to the damage to the coving where it looks like the water has come through.
Still don't know how its getting in though?!