Hi, I have a 1920's detached house, with loads of condensation problems thanks to over-insulation by previous owners. Every winter we get loads of damp and black mould thoughout the house.
I'm starting a number of projects to attack this, first of which is a couple of built in wardrobes in the master bedroom. These get lots of mould which is ending up on my wife's clothes, so it is right at the top of the priority list! :)
The cupboards are fitted wood construction, floor to ceiling against a solid brick external wall. One is between an closed chimney breast and external wall (i.e. it covers the corner of the house), the second is between the other side of the chimney breast and an internal wall, so only the back of that one is external. The external wall is normal solid wall construction, with a render coat on the outside that's been painted with Weathershield type stuff. Immediately above the cupboards is the loft, which has bits and pieces of insulation but doesn't seem to be ventilated at all (which is probably project number two). The external wall in question is north facing.
Even with everything else I'm doing, we're going to really struggle to get decent ventillation in these, due to them being packed with clothes and being built out of walls on three sides (if you include the Chimney). In the winter, you call feel how cold the extrenal wall is, and being in a bedroom there is quite a bit of warm moist air floating about. Plus both are lined with wallpaper which merrily absorbs the moisture to provide a cosy home to black mould.
I have the following plan to try and fix this without major work and was just wondering if some more knowledgeable people than me could give me an opinion on how well this will work and any potential pitfalls.
I'm planning to take out the internal shelves, etc, then strip the wallpaper. I'll then clear out any mould with fungicide, make sure the wall is sound (it appears to be from investigation) and paint with a fungicidal paint. Then I plan to line the external wall parts of the cupboards with an insulating laminate, something like polystyrene or Sempatap, that kind of thing. On top of that I'll then put some thin wood board to make a new wall surface, which will then be painted itself with fungicidal paint. I plan to use a relatively thin sheet of insulator, as I don't have much space to play with within the wardrobe and still leave it useable. Not sure about fixings yet, might glue the insulation on, but will probably use screws through to the wall for the wood board as it's thin and will need to be held fairly rigidly.
I'm hoping that this will provide enough insulation to avoid the wall surface geting cold enough to generate the condensation. Bear in mind the room itself is kept reasonably warm, its only these walls in the back of the cupboards which get this problem (in this room anyway). Getting rid of the wallpaper will hopefully help as well.
As it's a cupboard lining, I'm not too worried about how it looks, provided I can finish it neatly. Plus we won't be mounting anything on the wall so it doesn't need to be structural. I'll also probably cut a couple of vents into the cupboard to help with ventilation (there is a thin strip of thin wooden wall proud of the chinmney breast on each side which would be ideal for this).
I'm aware that this sort of lining can cause issues of moisture within the walls, but I'm hoping that since I'm only doing this in a realtively small area at the back of the cupboards it won't be severe enough to cause any problem. Plus I won't be lining the chimeny breast side (as it doesn't get particularly cold), so there should still be ventilation into the walls through that.
Overall I recon I can knock this out pretty cheaply and quickly, probably a weekend per cupboard, and score some good kudos with the wife.
Do you think this will work? (having the mould come back, even if at a reduced rate, would be bad for my kudos and health in general) Also, are there any pitfalls I should be careful of, or is the whole thing a long term bad idea in general?
Any advice appreciated.
