skimmed

Hello, We’ve just had our bathroom professionally renovated and the our old Artex ceiling skimmed and painted. As you can see in the pictures, the ceiling has started to crack along the full width of the room around the doorway, and another small crack and a small bulge has formed around the...

Rendered and skimmed wall, vinyl paint. What is the vest prep? It doesn't seem like a good surface to tile, maybe a good scoring with el diablo or a plasterers roughing out saw? Maybe bolster the skim off? What's the usual way to proceed? Thank you Dain