Mould

[rosswind]

Hi all,
I recently discovered mould in the bedroom wardrobe and on some clothes. Add this to the occasional musty smell and a small bit of mould on the underside of the matress. Took the matress outside into the sun which has solved the problem there. I have a dehumidifier in the room which seems to be working at the moment.
My question is how do I stop the problem?
Its an old house which had the stables converted into two bedrooms. I cut a hole into the dry lining and found an empty space about 6-9 inches to the inside of the outside stone wall(and a gale of wind!). Essentially a box was dropped into the stables with no insulation to the walls. The ceiling has about 50mm of white aeroboard which I assume is grossly inadequate. The floor seems fine(fingers crossed).
Do I need to insulate behind the stud walls (painful)?
Can I fit an insulated plasterboard to the one that is already there?
Do I need to ventilate to the outside or is the above mentioned gale adequate to aid circulation(through the attic space)?
Any ideas would be great!

 

[Paulone]

Sounds like the buidling is inherently damp and the creation of the internal studding has cut down the airflow to the point where mould can form.

If you can't keep windows open and the air circulating (hard enough) the dehumidifyer may be the best current option. You might also find the room benefits from being kept warmer. You don't say whether there's any heating installed, and some of that mould sounds like it could be resulting from condensation which is a sign of an intermittent heat source meeting damp air.

I agree that changing all that studding would be a very painful job. I've seen it done where a moisture barrier was placed between the studding and the wall, and I've also seen how the installation of a properly insulated floor makes a huge difference too... but these are major works and it sounds like this isn't a desirable thing to do right now.

 

[Teabag]

I would recommend getting a structural engineer to do a report on it and make recommendations.

 

[sydthebeat]

i agree with teabag.

mould can be cause by any of three things

1. inadequate ventilation
2. excessive condensation
3. rising damp.

Its easy to see if its caused by rising damp because it will occur mostly on low level. as there is mould on clothes in a wardrobe id say its an amalgamation of both inadequate ventilation and excessive condensation.

1. you need to ventilate
as this is a renovation the easiest way is to ventilate from the ceiling to the outside. do this in all rooms
2. you need to take down the existing studwork. you need to incorporate a breathable vapour membrane (tyvik) to the external of the studs and insulate between the studs with rockwool battens. Then reslab and skim.
3. upgrade the ceiling insulation by laying another 200mm of rockwool over the aeroboard.
4. dont assume the floor is fine. if you are doing remedial work, drill a hole in the floor and check the make up. if theres no insulation or polythene, and if you can afford it, take up the floors and incorporate insulation and polythene (DPM).

 

[rosswind]

Great to hear from those in the know. I had a crawl around in the attic and it seems like the old walls of the stable are still the old walls of the stable. The stud walls were thrown up on the inside and the stable walls were plastered on the outside. To look at the rooms you would think it was a new build, hence why I did these rooms first (decorate was all that was required, so I thought). I've already started another bedroom in a different part of the house (old farmhouse) so am looking to alleviate the original mould/damp/condensation/ventilation problem in the medium term ie. for at least the next year.
We have oil heating and a recently installed stove which throws some heat to the bedroom.
My question now is: Would just insulating the attic space add significant heat to the problem bedroom or would this be negated by the lack of wall insulation?
Bearing in mind I live on the side of an exposed hill, will venting to the outside increase drafts and decrease heat? Can I vent into the attic space or does it have to be outside? I can just about see outside in the attic anyway?
Any comments greatly appreciated.

 

[rosswind]

Is it possible to fill the gap between the plasterboard wall and the old, solid, stable wall with beaded insulation or does it require a vapour barrier between the two?