I'm having issues similar to those described elsewhere, with condensation forming on the bathroom ceiling during the cold weather and leading to black mould.
I'm on the top floor of a block of flats and the corner of the bathroom is inset to create a column for the soil pipe, which runs all the way down to the ground. It also extends into my loft from where it has a ventilation outlet on the roof.
It is around this corner that the condensation is forming, presumably because it is the coldest surface? I've applied a mould remover and repainted the ceiling, but the last couple of months the condensation has resulted in the ceiling wallpaper beginning to flake and fall off (again, just in the area surrounding the soil pipe.
My question - does it make sense to try to insulate the soil pipe? The only access is to the part in the loft. Or any other advice as to how to stop the condensation attacking this area gratefully received. I'm running a dehumidifier already.
Thanks in advance