Hi, we moved into our new house this year in the summer and one of the first jobs I did was to reglaze a broken skylight. The skylight is a fairly conventional wooden box with a metal frame on top. It doesn't open or have any vents. It originally had one pane of georgian wire glass (and flashband covering the crack). I think it was 8mm thick, but this was replaced with toughened laminated glass of the same thickness. The frame was resealed, but I'm now getting a lot of condensation on the inside of the glass. It's been damp as soon as winter started and is starting to make the plaster crack. I guess it's a fairly bad place for condensation; it's right at the top of the stairs, at the highest point of the house, and just along from the bathroom door. The house was extended in the 1970s and this is in the "new" part of the hallway. It has a flat roof immediately above it. Does anyone know a way to prevent this from happening? I know I could use a moisture trap in the short term but I wouldn't want to spend every winter with pots of silica gel on the carpet.