Mould

[Graye]

Anyone with ideas on this please? We seem to have a mould problem in our bedrooms. This isn't the mould you see on damp walls etc, ie black. It's more of a white mildewy film which is appearing on anything leather, straw/wicker etc and even on some clothes in the wardrobe.

The house is relatively new and insulated, is centrally heated and we have been using a dehumidifier in there. It is double glazed and there is no mould in the actual plaster/wood etc., the walls don't feel clammy either.

The only cause I can see is that the house is built into a hill with a cellar, quite large at one end (under the bedrooms) and tapering away to nothing at the other end. This is all bone dry underneath except for the first "room" which is full height and has a concrete floor with a channel for "off flow water" from behind the house. This is just a trickle and is covered with boarding etc. The ceiling is plastered straight onto the floorboards of the bedroom above.

At the moment we are wondering whether applying a separate ceiling to the joists with insulation in the resulting gap between might solve this but don't want to just hide the problem, we would rather actually fix it if possible. Re-routing the off flow isn't an option, at least not in the short term ie this winter. Any ideas/suggestions would be gratefully received!

[boboff]

Hello
We live in a valley and get mould.
Leather gets eaten by the same stuff.
The only real treatment I have found in regular spraying with bleach diluted in a bottle, and ventilation.
Shoes and bags and coats etc are kept out, better in the shed / loft even, than in a bedroom, where the atmosphere is allot more humid, especially if like us it's en-suite and well all shower in it every day.
Check your soffets also for ventilation holes, and make sure you have a good 300mm of insulation on the cieling. As for the floor personally I would go with a really good 11mm underlay and decent carpet, rather that insulating the cellar as such.
Look around outside as well, clearing trees etc to get a better air flow has helped us I think.

[Graye]

Thanks for those great ideas Boboff. I've opened the transom window already!

Funnily enough we are also in a deep valley and have a small river running through the garden so we are probably likely to be prone to dampness anyway. There is an ensuite too, although not directly off the bedroom. Our bedroom is almost a totally separate part of the house with door into a hall, door into a bathroom and door into the bedroom. On the other hand, the bedroom also affected with the same problem (but to a lesser extent) is just before that hallway so pretty close.

There is already amazingly thick underlay (I did wonder about that) so someone seems to have tried to address things before (we've just moved in). Also the fitted wardrobes are lined with very thin polystyrene "paper" so that might be something to do with it too. The house was empty throughout last winter so I wonder if that might contribute too.

I shall ask the lady who lived here some years ago, she might have some insights too...