I am moving around 2 bedrooms and a bath in a remodeling project on an older home to reposition the stairway. I have already gutted the walls but was wondering if I should remove the plaster and lath ceilings before I put up the walls?

The ceilings are fairly solid but I was thinking about removing them because the electrical wiring now comes into the walls in this home from the attic and I thought it would make rewiring easier. And thought it would be better nailing the top plates of the new walls directly into the ceiling joist instead of through plaster and lath.

Does anyone have any recommendations as to whether I should remove the ceilings or not that have done work like this before?