Patching and Plastering - removing a section of plaster

I have to remove some plaster as part of a bath remodel. The problem is that there is metal lathe between the wall and the ceiling. How do I cut this at the top of the wall without disturbing the ceiling? I have left about 6 " of the original plaster and tried to match the thickness with drywall in the past, with only so-so results.:confused:

It is a big mess--dust everywhere but you could use a diamond or abrasive blade right in the angle and get everything but the very corners.
A wide, rather sharp chisel will cut the plaster and lath fairly neatly. Judicious work with a hammer will loosen the plaster from the lath on the wall then you can cut the lath with snips. The sand in the remaining plaster is death on snips, though. If the plaster is well bonded on the ceiling you can often rip it at the angle simply by pulling on it, however there is a risk of pulling some from the top also.
I think if I were doing it I would opt for the wide sharp chisel but if I damaged the plaster on the ceiling I know how to fix it.

Well I took the easy way and left about 18" of the original wall. I had to make room for a multi-piece tub and shower unit and it was only 76" tall. I used a spiral saw, very quick, very dusty. I still had to use snips in the corners. I'm going to put 1 row on 8x10 tile above the unit, and it should come out okay.
Thanks for the reply.

Thanks, Harry, for telling us how it went. Come back if you have anymore questions. Good advice, tightcoat. I usually just hack away at the mesh with my drywall axe. I think a chisle would be much better.

I hadn't thought of the spiral saw. That is a better idea and I think an easier tool to handle than a saw or grinder with an abrasive blade.
Never stop learning.

I know not to worry about the 1' gap caused by the nail flange on the surround, and just let the wall tile cover the void. But can I attach the 1 row of wall tile directly to the plaster? Or should I use cement backer board. This job has already been 2 days and 2 trips to Home Depot and 2 trips to Menards. Not to mention the trip to Lowe's last week to buy the surround.:confused:

Plaster is not a good tile base for wet locations. Gypsum plaster does not stand up well to continuous moisture. However, since this is above the surround and should not be subject to continuous moisture I think the plaster behind the tile will stand up until you remodel again.