Coving or caulk on uneven/bowed ceiling edge

[battenburg]

I live in a Victorian terrace. The ceiling in the front bedroom looks like it has either been replaced or plasterboarded over - I don't know which - in the relatively recent past; its in reasonably good condition and there is a new light fitting. But, it seems like it may have been something of a bodge job as its a bit bowed and uneven and it looks like quite a bit of filler has been used along the longest interior wall where the celing abuts that wall.

There has been a little bit of cracking along this join since I moved in, which I wasn't particularly bothered by. However, over the summer I had some boarding done in the loft. Following the work, the crack at the join has now extended along most of this wall and a few little pieces of the edge of the board/filler has fallen out. I assume this is because someone was moving around in the loft and it caused the joists to flex just enough to cause this.

I'd like to stop any more bits of plaster from flaking away and thought that coving would achieve that as well as covering up the current cracking. But, I'm concerned that where the the ceiling is uneven, trying to install coving is going to be a challenge and it may be tricky to get a good finish without also making it much more obvious that the ceiling is bowed.

My priority is just to stop the flaking (aesthetically pleasing would be nice but is secondary), so I'm wondering whether decorator's caulk could work for this. I'm guessing it would be fine along the crack (which is just a mm or so), but not quite so surely whether it would be suitable to fill in where the edge of the plasterboard has broken away. This is just a couple of sections that are maybe 2-3cm long and 1cm wide. Can it be used for this and then painted over? Or would I want to use actual filler? I'm new to this and haven't used either!

Any advice appreciated - thanks!

 

[opps]

I would start by sanding the crack flat. Where the gap is more than 1mm I would then use filler and sand it back. Once done, prime the filler and then use a MS polymer (eg Sikaflex, CT1, Puraflex 40) rather than decorators caulk. Decorators caulk goes hard in time, MS polymers remain as flexible as silicone but unlike silicone, they can be painted over.

I haven't seen the ceiling but agree that the coving may make the bow even more obvious. If the ceilings are sufficiently high, you could add a picture rail and paint the area above the same colour as the ceiling to make the bow less obvious.