There is usually lots of room , the only hassle is plaster that has sneaked through the lath . A good fish tape usually works well ! Of course the upright studs are approx .Need help running horizontally through old plaster and lathe walls. Any help minimizing the number of holes in the wall. Should I be squeezing the romex between the lathe at the studs and so as to just make small openings at the studs?
If you can't fish from above or below, then popping the baseboard is your best bet. The plaster that sticks between the lathe is called the "key", and it is crucial to the structural integrity of the plaster, so avoid damaging that if at all possible. Without that hardened key, the poor elasticity of the plaster to the rough lathe is the only thing keeping the lathe on the wall.There is usually lots of room , the only hassle is plaster that has sneaked through the lathe . A good fish tape usually works well ! Of course the upright studs are approx .
24 " apart !
You could do that, but that is a last resort for me. Lots of work, lots of mess, and tough to patch for it to look right.If baseboard removal is not an option.
Is it ok to notch out a little at studs, lay in romex flat, protect with steel plate? Fish behind wall from stud to stud. Maybe this will minimize the lathe that is removed?
If you do that a FHA strap would be required to protect the romex 1.25 inches from the nearest edge of stud NEC 300.4Need help running horizontally through old plaster and lathe walls. Any help minimizing the number of holes in the wall. Should I be squeezing the romex between the lathe at the studs and so as to just make small openings at the studs?
Although the OP hasn't said so, it doesn't sound like he has a basement or attic that is accessible. Otherwise he probably wouldn't have asked about notching or pulling the baseboard.Ideally you should fish vertically either from the basement or crawl space to the attic our second floor. It is quite easy to remove ducts or floor boards for fishing. I wouldn't recommend notching the studs our fishing between the lathes. This could just make it harder for you. Get a twelve inch long drill bit (I personally like the Bosch daredevils, they hold up well and are cheap) for going through th bottom plates because of the pileup of plaster inside the wall. I also recommend a grinder with a diamond cutoff wheel for any boxes you need to cut in. It makes a perfect clean hole through both the lathe and plaster and holds up great. Good luck fishing
I do it this way too. It takes time, patience, and practice, but patching plaster is not in my skill set.Nothing easy about retro work. Plaster especially is tough. It is possible to fish through 2 studs with only two holes.
notch |stud| <fish> |stud| notch
All the plaster concrete usually ends up on the bottom of the baseboards making baseboard runs fun.