Hi,
I have coving in some areas of my house and none in others but the same problem occurs ..... CRACKS !!!. Every winter the cracks appear where the walls meet the ceiling (where we don't have coving) and where the walls meet the bottom edge of the coving (where coving is present). The house extension was built nearly 20 years ago so shouldn't be moving around. In addition, to the cracks I have noticed in the same locations that the plaster appears loose..... when you run a coin over the plaster it changes the sound and becomes dull which indicates that the plaster has lost its bonding.
I repaired it once and found that the paint layer appears to be 1-2mm thick elasticised paint..... It looks like the whole house was sprayed with a final finishing coat that covered up imperfections but could be acting like an insulator (holding in the moisture). Behind this elasticised layer is a 2-3mm skim coat that is the plaster areas that is loose and comes away from the wall. The plaster behind is sound and no issues. So in summary it looks like a bonding issue but how I solve it and why the cracks appear in winter is beyond me. I used a flexible filler thinking that it would solve the problem but it didn't
I asked a couple of builders and they said I needed £000's spending so I thought I would ask the forum if they know or have heard of similar cases.
Thanks for any help or assistance on this matter. All the best MIKE