Recently moved into a house with newish double glazing. Finding mould in the coners and on the windowledge, condensation on the window glass and anything fabrick on the wall (ie hang a coat on it) and it too develops mould. This is an outside wall in a 25year old house. The gutters are clean and no sign of any roof tiles being missing,broken or loose. This is upstairs but the problem is also downstairs. Anyone any ideas on this one??

Mr Ray Stockton, February 2008

The problem is due to humidity/water vapour that you put into the house by breathing and general living and your handling of the heating system.

Every time you turn the heating down or off, you unbalance the humidity/heat relationship.

For every temperature there is a specific amount of water vapour that is held in suspension.

You describe the effects of condensation.

Each time the temperature drops, its ability to hold water vapour diminishes - that water has to go somewhere, usually it will condense onto the nearest cold surface, a window. In your case its an already damp cold wall.

To quickly solve your problem, you need to buy and keep on a de-humidifier. Leave it on 24 hours a day remembering to empty the tank.

Within a few weeks the problem will go away.

Perry525, February 2008