Source
r/DIY•
cnphilli

Replacing plaster and lath with cement backer board and tile.

home improvement

I'm removing plaster and lath to install cement backer board and tile in my bathroom. On one wall I am only partially removing the plaster so I need to somehow make a clean cut and merge the two. I can't find the right words to Google this, can someone help me with advice or links? My main questions I have are: does the lath need to be cut along a stud and how can I avoid cracking the plaster that will be left?

Posted May 6, 2018, 2:41 AM UTC

05
jkhabe•

Watching for answers.... I am doing the exact same thing in my bathroom soon.

My initial plan is to cut the lathe and plaster straight down the side of the 2x4 framing so the lathe remains nailed to the original stud. Will probably shoot a little construction adhesive along the edge to glue it down the lathe and provide additional support. I then will screw in another stud along the existing stud to give me a solid attachment point for the cement backer board.

There is a couple of ways you could accomplished the cut. I’ll probably use either a recip saw and/or a circular saw with a cement cutting blade.

2
cnphilliOP•

I like the adjacent stud idea. You don't think the circular saw will cause the plaster to crack?

1
jkhabe•

No. Use a masonry blade (you can get cheap diamond saw blades from Lowe’s, HD, etc) and do your first cut through the finish layer and then do subsequent cuts getting a little deeper until you are down to the lathe. I’ll probably use a oscillating saw I have to do the ends that the circular saw can’t do. Cut the lathe off with a recip saw or circular saw with a thin kerf blade and your good to go.

2
civ_iv_fan•

ive tried different methods and this works the best for me and generates the least dust:

  • outline in pencil the plaster you want to remove
  • cover the floor below with plastic or a sheet or something
  • with a nice utility blade, a straight edge, and a dozen or so blades on hand score the plaster all the way down to the lath. This will prevent the removal of the plaster from screwing up the plaster you want to keep
  • use old flat head screwdrivers and a small crowbar/wonderbar to remove all unwanted plaster
  • leave lath in place (this is wood lath I assume)
  • measure the thickness of the saved plaster. It should be about 1/4” thicker than your cement board
  • add spacers to lath that so that when you mount the cement board, it is even with saved plaster. New wood lath might be about the right thickness, you could strategically mount in perpindicular to existing lath
  • mount the cement board on the spacers

If you need to remove the lath for utility access, I’d advise taking it out to the studs, instead of trying to take out a section in the middle. Remember to add spacers on the studs so that the new wall lines up with the old

2
Angelsoho•

Wear a mask on demo day. That dust gets ya.

1