This is regarding a possible rehab of another property that I own. It's an
older home with wood lath and plaster wall. I am considering tearing out
the lath and plaster down to the studs, then having it rewired throughout,
then having the ceilings and walls sheetrocked. I would rather not
sheetrock over the existing lath and plaster.

My question is about how contractors typically go about doing the sheetrock
over the old ceiling joists and wall studs. How do they deal with the fact
that after the demo of the original lath and plaster, the ceiling joists and
studs are often uneven -- that is, not "planed".

Do they usually just do the new sheetrock by going with what they have and
just shimming the areas that need to be shimmed to end up with a flat,
"planed", and even new sheetrock wall? Is there some other way that this is
usually done?