Damp issue

[oafc2008]

Hi All

Looking for a bit of advice. Bought my house about a year ago and since then I have noticed patches of black damp forming in the upstairs rooms and around the doors downstairs. The bathroom is the worse effected. The mold will appear on the roof, around the windows beading/wall contact, around the bath (around the sealeant / tiles). We also have it in the bedrooms, mostly appearing in the upper corners.

Its sounds alot worse than it really is. I will knock up some photos tonight so I can show better. Most of it has wipped off using a anti mold spray I got from B&Q. Although the mold has discoloured alot of the surfaces. But it just seem to be on the celling surface rather than "coming through" from the roof if that makes sense.

I took a quick look in the loft and there is very little insullation up there. My gutters are abit leaky as well. So there are two factors which wont be helping i would guess ? Im going to go up tonight and look at the joists etc to see if there are any signs of damp / mold etc... will let you know...

Im just wondering how to takle the issue. Where to start. Do I need to get a expert to look at it... Worried about being taken for a ride and paying for unnnesccary treatements etc!

Also any advice on how remove the staining from the window areas ?

[Chiltern Handiman]

Sounds to me like a classic case of poor ventilation....

Couple of things to check...are there extractor fans in the bathroom and kitchen? Both these areas produce a lot of humidity and if there are insufficient air changes it will condense on cold surfaces such as windows and uninsulated outside walls.

The black staining is actually fungal spores and you will need to use a cleaner with a fungicide to remove it completely...if mot it will just grow back!

[Avocet]

This is of interest to me too. We have a modern house (less than 15 years old) and the interior walls are painted with magnolia emulsion. Over the last few months, I've noticed very faint stains - a sort of yellowish discolouration in a few areas - usually top corners where two walls and the ceiling meet. This only seems to happen on the inside of external walls. Is this mould? As far as I'm aware, the house is quite dry. We have a hygrometer in it and it seems to read in the region of 35-40% humidity most of the time. It's double-glazed and pretty well insulated. Obviously it's winter and we don't have the windows open much.

If it is mould, what's the best way to treat it? I wouldn't mind re-drecorating anyway as the paint is original and a bit grubby in places (generally at "child height)! Should I just wipe with some bleach before re-painting?

I borrowed a moisture meter from a friend who works with wood. Obviously, it's not calibrated for plasterboard, but I stuck it in several walls and the readings it gave were generally the same in the ?damp? areas as in the non-damp areas round the rest of the house.

[jozeffo]

OAFC - chack your vents in the soffits (under the guttering) and as suggested the ventilation in high humidity areas. Lack of insulation will show up such a problem and you ought to get it done as there are grants and it pays for itself in a couple of years. If your double glazing has no trickle vents in it this may contribute to the problem. Look for blocked up airbricks. Try a humidistat fan in the bathroom rather than a timer.

Avocet - You may have a problem with efflouresence. Google it. The moisture content of the walls will fluctuate so when you tested, it may have been low, hence no difference in the reading. Alternatively, the paint may be imporous, preventing a meaningful reading from the damp meter. Check the ventilation is ok and if you clean the walls, use fungicidal wash and sugar soap in that order.