There's a gap appearing between the cornice and the wall. It's been there close to a year but is getting worse. There's also one appearing actually running along within the cornice as can be seen in the pic on the right (nearly the wavy bit). Scattered cracks also. Any idea of cause? I pushed up gently with the vacuum hose to see if the cornice had any spring in it to check if it was sagging and only succeeded in nearly pushing the hose through the actual plaster/cornice - I heard/saw some cracking appear too. So who fixes this? Plasterer? Painter? Please say it's repairable and I don't need a new piece.