plaster repair

What’s the best way to cut a somewhat nice straight line thru plaster without cutting the lath? I’ve got some plaster washers to pull the loose plaster back to the wall, but some of the plaster has been removed, and I want to replace it with drywall. I want to leave the lath in place because it’s holding up a bunch of blown in insulation.

I use a utility knife. You’ll probably go through a bunch of blades, because the plaster has sand as a component. Take a light cut at first to establish the line, then take a couple more passes to cut through. Try not to flex the lath behind too much as you’re pressing, or you may find yourself turning sound plaster, nicely keyed into the lath, into unsound plaster.

And you probably know this, but the plaster buttons should be screwed into the studs, if at all possible.

That’s what I ws thinking. I’ve got a few spots that are about a foot by a foot, and the scraper I’ve been using to remove the wallpaper (buried under at least two coats of paint, the top one textured), does a decent job. But one spot is 3 feet by 2, and on the inside of a valley (this is in the attic), and was hoping of an easier way to cut such a long line.

A rotary tool will make quick, albeit dusty, work of it.

It’s actually not that arduous. And I would make sure to go stud-to-stud when cutting such a large bit of plaster out, so that you’ll have something solid to fix the patch to. I would also use mesh drywall tape over the seam between the patch and the existing plaster.

I like this carbide scoring tool for cutting into plaster. It’s designed to score cement board, it’s tough and will make short work of plaster. I used it to widen some hairline cracks for filling, it runs rings around a utility knife.

Start with a straightedge, once you get a shallow groove cut, the tool will stay in it, and you’ll cut through in just a few minutes.

So, I’m starting to use the washers, and I’m not sure if they go concave out or in. They look like nipple shields, so if I put them in, I have to make a deeper hole, breaking the skin of the plaster. Nipple out, I have to hope that the screw pulls it in far enough to not stick out too far. I’m thinking out.