Have had spots of mould in the corners of my bay window for some time now, don't think it's damp as when I laid a new wooden floor last year and removed skirting I could see the bare brickwork and it was dry as a bone. Seems to be worse in winter which suggests it may be condensation building up. Also the brickwork is single thickness. Just wondering whether to tackle this from the inside or the outside. Presumably I need to create some additional thickness by either having another course of bricks added to the outside or maybe add some stone cladding or would I be able to maybe batten out from the inside and use some plasterboard to create a gap between the wall and the plasterboard, is the latter feasible and if so would I need to use some sort of special backing on the plasterboard. Any advice would be appreciated.