Revisions log for Answer #1169

The reason for the formation of damp under the sheet plasterboard most likely – lack of ventilation between the plasterboard and the wall, ie it was in a vacuum, and to eliminate this defect, you need to arrange ventilation grates are approximately the same as they do on the floor, in the corners below and above.

It does not take into account the gap in the outer wall between the apartments and plasterboard upholstery – a strip width of 50-100 mm, it is the main reason for the formation of all the problems.

Therefore, the second way to eliminate this problem could be to insulate this section of the wall from the floor to the ceiling, but it is unlikely to eliminate the problem, because the cold bridges will still remain (technically difficult to solve the problem with thermal bridges in secondary housing – easier to solve in the new construction) and especially if their area is large, and probably the floor and ceiling will also have to insulate – they also come in contact possibly through insulation and the outside air, the ceiling through the attic and the floor through the basement – so the best solution – it ventilates

Mildew is very difficult to eliminate. It is better to dismantle your construction and plaster it again – it will be cheaper.