Damp patch in ceiling after frost

It seems from your description that you already know the cause. Air can hold moisture and the warmer the air the more moisture it can hold. That moist air is then cooled by coming in contact with your cold walls and hence the damp. What I would suggest you do is clean the damp with a mould and mildew spray. Once the wall is dry paint over the area prone to mould with some damp proof paint. Hope this helps, Shanay Hirthe

It seems from your description that you already know the cause. Air can hold moisture and the warmer the air the more moisture it can hold.

Hi, Which room is the damp appearing in . It seems like it could be ventilation issue . Bleach will kill clean the black mould off the wall however the problem will keep returning should you not find the source of the problem . Should it be a bathroom where there is a lot of condensation I would suggest looking at the ventilation / fan in the room and religning the wall / ceiling with an aqua panel . Other rooms, ie bedroom , it could be an issue with lack of insulation in your cavity’s or be a case where dry lining the wall or ceiling or installing a vent in the room will fix the issue Yes you can clean and paint with mould resistant paint and this will work . However , in my opinion the problem will reappear eventually should it not be tackled at the source of the problem, which is identifying where the condensation/moisture is coming from and eliminating the moisture forming in the first place .