We have a bay window which has its own separate roof made of some sort of metal material. We have just replaced our double glazing and the chap mentioned there was no insulation in the void and that was why we were getting bad mold on the ceiling there.
What can I do to insulate it, there is no access other than taking off the roof part. Could I go through the ceilinf below and replaster? And what should I insulate it with?