8 years ago I had my living room plastered but as it was artexed with a deep profile, the plasterer had to apply a couple or layers of plaster. Coving was then fitted. There were no problems. though I was loathe to hang any pictires for fear of causing a disturbance. There were some hair line cracks where a fireplace had been removed and the space boarded but these were due to the shrinkage of the different surfaces under the plaster. This tear I had a painter in to decorate and he filled the cracks which are now ok. Several weeks later we decided to have a new roof fitted and hardly had they finished when a crack appeared along one wall where the coving joins the ceiling. The painter had a look and thought it was just a case of digging out and applying filler. So I didnt claim from the roofer. However the crack has now reappeared but further along the roof from where the painter filled in. Is it ok to repaeat the process and why is it only happening at one wall. if as I assumed it was caused by vibration when the tilers were fitting the roof. A small crack has appeared in another room in the same place but nothing much to speak of. there is no coving in that room and te crack is at the joing between the wall and the ceiling. Any advice would be helpful.