Cutting coving around warm air vent?

[Gareth]

I'm trying to install ceiling coving in a four walled room.

I'm encountering two problems: 1) two vertical (floor to ceiling) pipe boxes one in a corner and one on a straight wall and 2) more difficult to solve an old/unused warm air heating vent grill fixed to the wall about about 3 inches from the ceiling.

Removing the vent would leave a book size hole in the wall that would need to be filled and finished and painted. Too much skill and paint matching involved in that. Is there a way of fixing the coving flush over the vent? I think I would have to create a small section of coving just for the length of the vent (about 12 inches) and then trim the depth of the coving by a few mm so that it is flush with the wall when the untrimmed coving is placed around it. I wonder even if I could get the coving flush whether or not it would look silly partly covering a vent.

Actually, come to think of it, as I write this I realise that the pipe boxes may be more problematic than the vent. There's surely no easy way of fitting coving around a pipe box?

[Mr Fuxit]

Are you intending to fit coving without painting the walls afterward?

[Dave Liquorice]

How big are the boxes in relation to the coving? If the boxing is only an inch or so smaller or larger than the coving I'd pretend it wasn't there. Cutting the coving to fit the boxing.

If the boxing is large in comparison with the coving you'll have to take the coving around:

Removing the vent would leave a book size hole in the wall that would

That's a shame as that is the only decent option IMHO.