Hi everyone sorry if I have put this thread into the wrong area. I own a 1950's property which until last week had horrible unsightly concrete gutters, but I still find I am getting condensation issues in the upstairs bedrooms where the ceiling curves to meet the walls. I know I have to put more insulation on the flat ceiling in the loft and I am not concerned about doing this. but obviously the curved or slopey section of the ceiling needs insulating. I have read a thread earlier about using celotex or kingspan sheet, am I correct in thinking it is cut to the width of the rafters and then pushed down into place in the void area, and how do you incorporate the curve into it cut another piece and place next to it. Or is it possible to use space blanket which is wrapped in foil to insulate the curve/ slopey part of the ceiling but maintaining the ventilation gap. Many thanks for looking.