I have stripped my hallway ready to sort it out, but 3 of the walls have external bullnose corners, merging into a 30cm section of square corner at the top. This obviously presents papering problems, so I would like to square up the corners the full height of the wall.

What’s the best way to do this? I’ve no plastering experience and wouldn’t trust that I’d do a good job of it. I’ve seen corner tape – how is this applied in this situation if possible at all?

d’ya mean its got a 1″ diameter “broomstick” moulding up the external corner?

you would need to stick some angle bead on with some plaster/filler then fill in ti the clean edge after its gone off.

alternatively 2 small strips of wood glued into a right angle or something similar then glued onto the wall with “no nails” type glue if you want to make it into a feature and paint/stain them?

Attach a temporary vertical batten one side of the corner (using the square upper section as a guide) so its flush with the square edge, fill gap with plaster, level off using the wood as a guide and leave to set. Remove batten and fix to other side and repeat by attaching the batten to the other side of the corner (2nd side should be easier)

And hope the skirting matches up with the new corner (maybe check this first!)

Depending on the radius of the bullnose, have a look at:

a drywall thincoat angle bead for a small radius. These only need 3mm of finish plaster

or a standard angle bead for a larger radius. These are bigger all round but need 12-19mm plaster

Wood can “move” and tear your paper in time

It’s quite a big bullnose corner, probably 4″ diameter so I have resigned myself to the plaster option. Thanks. I’ll try a wooden guide to get something resembling a flush edge, then a thin coat corner bead and skim the full wall I think.

Assuming that it’s brick behind, I’d be knocking the plaster off the corner, going back about 4″ onto the flat walls, then drilling and screwing a piece of timber to the wall allowing for a small piece of plasterboard. Bead the corner, scrim tape over the joint then fill it out with some bonding, finally skim over.
Alternatively, You could probably just form a corner with a couple bits of plasterboard and some board adhesive.
Either way, go back onto flat walls a bit to blend in new/ old plaster.

Angle bead works great, I’ve done all mine
Get some plasterboard adhesive, stick the bears on with them , finish off with finish plaster , not a massive job and gives a great crisp corner