DIY Doctor UK DIY Forums

[b]We have been renovating a house in France for five years. Obviously, when left empty for periods of time, we expect a musty smell etc., but in the last two years we seem to be having problems with mildew/damp/wet walls in the lounge - spreading mildew onto the kitchen chairs!! Have we caused the problem. About 2 years ago, we decided to insulate the "cave - cellar" directly beneath the lounge (because felt draft through edges of floorboards - so pulled down all the old polystyrene that was beneath floorboards in the cave and replaced between joices, directly to the underneath of floorboards, rockwall and then covered with silver insultation bought from Wickes. Thought we were doing right, but seem to have increased mildew and the lounge outside wall seems to be quite well behind the armchairs. Will an airbrick on the outside wall and perhaps a floor grill/vent the opposite side do the trick to thelp ventilation. Don't really want to pull all the insultation down underneath in cave - as we worked so hard putting it all up!! WOULD REALLY APPRECIATE ANY ADVICE OR HELP, so frustrating that our hard work seems to have been in vain!! [/b]

every house needs to breathe ,heat cannot escape and causes condensation when its cooler at night.
I would install trickle vents in all the windows giving an airflow to each room,this will give a chance for air to circulate and dry out any moisture in the rooms.fitting an air brick will only allow air in 1 room and is a harder job to fit.