Cutting into Lath and Plaster Without Cracking It!

Here are a couple different methods to successfully cut into lath and plaster without cracking it. This would be the same process if you were to cut in an electrical box or ceiling fixture.
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[@gko818]

Omgosh, this is the cleanest DIY ive seen, and that's what has been stopping me from tackling this! Thank you!

[@jimboxmeyer1964]

Very good. A recommendation to keep down dust in occupied homes: I bought a 20 by 20 inch box fan and also a good quality air filter, also 20 by 20 inch. plus a "prefilter" of lower quality. Tape the high quality filter to the intake side of the box fan. Then on top of that, right up next to it, tape the lower quality prefilter. Face the filter side of the fan near where you will be making lots of dust inside the house and turn it on a high setting. It will such the dust right into the filter and clean air will come out the other side.

[@precisionmachineshed]

I've used that trick before. I have a HEPA vacuum that I use now that is rated to suck up lead dust. Does an extremely good job.

[@user-pw9lw4uc2g]

The easiest way which also generates the least amount of dust is to use a diamond blade into your multi tool and slice through plaster and lath simultaneously. The diamond blades last a lot longer than any other blades you can use.

[@tblacker]

I followed your process and was able to get a new electrical outlet installed much more easily than I thought. Thanks!

[@precisionmachineshed]

Glad it helped

[@wattage2007]

Got quite a bit of this to look forward to. This was a reassuring watch!

[@Leoneidas]

I've been looking all over for that PVC cement!!!

[@sandradelgadillo9430]

😂🤣

[@sandradelgadillo9430]

And i was just gonna ask if i can borrow it! 😉

[@mikewinburn]

Excellent presentation

[@86_kazuki35]

Thanks for the demonstration. Doing some work at my house with the same issue.

[@precisionmachineshed]

No problem.

[@okawesome5596]

Excellent approach. This is just what I need to move my bathroom fan. Previous owners put sheetrock right on top of the lath and plaster, so I have to go through all three layers to cut my opening.

[@mariad4183]

Great info! Tyfs!

[@mdchaney]

For cutting the plaster, you can get a bit for a dremel that costs about $15 and will cut the plaster like butter. Figure out how thick the plaster is, set the bit to that depth, and cut it first. Then finish up the lath with the oscillating saw.

[@JR-ch8rt]

Thank you for this amazing tip!

[@precisionmachineshed]

You're so welcome!

[@ksparks689]

Super helpful. Thanks!!!

[@jasonhannsz]

Multi tool with a diamond grout blade works kinda like the grinder but is slow enough that it won’t throw dust everywhere.

[@jfarinacci0329]

Good information. Thank you.

[@precisionmachineshed]

Glad it was helpful!

[@johndinofrio6143]

Very nice and efficient

[@BurtBowers]

I like the idea of what you showed drilling holes first then using keyhole saw then finally a multi tool, I have plaster walls house was built in late 50's but have no idea what i am up against to get to the plumbing as with studs in the wall the problem area is where the hot cold & drain is behind bathroom vanity I for sure need to get one of them multi tools at one of the big box stores.

[@Bansheekilr]

Cool, you found yourself a jar of PVC cement too.

[@precisionmachineshed]

Amazing what's in those walls. No gold coins though!

[@vince6829]

Thanks for sharing

[@danwas44]

Nicely done!. Another option for cutting the wood lath would be cut several holes in the corner with a drill and then use a Jig saw.

[@mdchaney]

A jig saw will severely damage the plaster.

[@tinaeisenhart7620]

Thank you

[@Ink.johnny]

Great vid.

[@precisionmachineshed]

Thanks

[@threeheavensmusic]

Good ideas

[@granden2077]

Hey Thank You. 🍻

[@AlecGrinage]

Taking down all the walls in my bathroom down to the studs using a dremmel. How can I get through the metal lath in the corners of my ceiling without mangling the metal?

[@brianmoore5498]

nice, i ned to repipe a house with lathe. thanks

[@Adobo121]

If you are doing a lot of these, an angle grinder with a diamond blade is best for the plaster. Then hit it with an oscillating tool

[@User-vs1bz]

Great video, thanks. How did you repair the hole afterwards? Did you end up using drywall?

[@precisionmachineshed]

It's still there. My plan was to ether finish the wall with tongue and groove boards, or make a false panel with cabinet detents and hang a picture or art over it.

[@edbouhl3100]

I've used cement board instead of drywall. Once its done it feels like the original.

[@FranklySpeaking73]

Nice work and great video! How about the same thing but with metal lath that laster wall?

[@precisionmachineshed]

Oh boy. I remodeled a bathroom on an airforce base once that had that. Fairly certain it was bomb proof. That might break the plaster. You could try chiseling a channel and using side cutters (wire cutter) to cut the lath.

[@LexpressionKos]

The angle grinder with a diamond blade for the plaster, and then switch to a metal cutting blade for the metal lath. There might be strapping behind the metal lath, which you can go through with the oscillating tool. A circular saw with the right blade might go through everything in one go.

[@JBridgetMcCurry]

I saw another video where the guy said to use a grout blade on the multi-tool for the plaster.

[@davidmatejka3598]

I did it today and it's amazing. I can't believe how much I have struggled in the past in my 101 year old house. I am now going to add those wall plugs I was afraid to tackle before.

[@WadaGoodIdea]

I use grout blade with my multi tool and that creates very little dust...

[@WadaGoodIdea]

And thank you for the video!

[@precisionmachineshed]

No problem. Thanks for watching.

[@davidmatejka3598]

I did that today and it was like butter.

[@flacoblb]

I like this alternative. The angle grinder method is very messy.

[@precisionmachineshed]

Thanks, I learned it from my dad who worked as an electrician back in the day where they had to do this quite often for outlets.

[@ralvarado16]

What other tool/method is less messy?

[@Vincerama]

How about using a sabre/jigsaw to jut the lathe?

[@buddyfd912]

Why is there a can of maybe PVC glue or primer behind that panel But anyway yes my house is old with alot of plaster walls your way I like I will be trying that very soon thanks for the tip

[@precisionmachineshed]

I'll have to go back and watch it. I did just remodel the entire bathroom behind that wall, so maybe I left it in there. wouldn't have been in there for more than a week or two.

[@user-wn7ke9gd2x]

Who left the primer in the wall 😂😂😂

[@edog3558]

He didn't mention he likely wiped out his jab saw. Most of them aren't made to saw thru plaster, which is a masonry product.

[@precisionmachineshed]

Yeah, after cutting several holes, mainly electrical boxes, it will wear out the keyhole saw. They are pretty cheap though.

[@Layarion]

but how do you fill the hole you just made?

[@precisionmachineshed]

Sheetrock. and mud. or make a cabinet door, or hang a large picture/mirror.

[@df4196]

what kind of drill tip are you using?

[@precisionmachineshed]

mansonry bit.

[@poolahpot]

is there lead in the dust???

[@precisionmachineshed]

My house didn't have any lead paint on the inside surprisingly. To the best of my knowledge, plaster usually didn't contain lead or is not a known cause of lead dust.

[@josecanisales3491]

Why were the water valves off?

[@precisionmachineshed]

Bathroom is getting remodeled and the valves were not yet installed.

[@dankamp2872]

Try a multitool.

[@precisionmachineshed]

I don't think a Leatherman would work very well. You talking about an oscillating saw?

[@dankamp2872]

@@precisionmachineshed Yeah, an oscillating tool. I normally don't like using these but I've seen a few videos where they seem to be useful with plaster walls.

[@-CCdude]

who's the "plumber" that puts shut off valves inside a wall!!! I would install a access plate for those valves....

[@precisionmachineshed]

That's what the hole is for!

[@olliecrow3547]

Doh!