Cutting Plaster on Wood Lath

[NewOnMyOwn]

I've been getting more and more jobs in houses with old wood lath and plaster. My method has always been to use a Rotozip with a tile cutting bit (I use the 1/4" bit hoping it will last longer than the 1/8" bit) to cut the plaster and then use a wood cutting Rotozip bit to cut the lath. Sometimes I burn the wood cutting bit up in the lath even if I go slow. This is a long process and the dust travels EVERYWHERE which isn't the customer's favorite thing to see.

What do you guys do? Tips or tricks appreciated!

 

[One-eyed Jack]

I've been getting more and more jobs in houses with old wood lath and plaster. My method has always been to use a Rotozip with a tile cutting bit (I use the 1/4" bit hoping it will last longer than the 1/8" bit) to cut the plaster and then use a wood cutting Rotozip bit to cut the lath. Sometimes I burn the wood cutting bit up in the lath even if I go slow. This is a long process and the dust travels EVERYWHERE which isn't the customer's favorite thing to see.

What do you guys do? Tips or tricks appreciated!

The newer rotozip have a vacumn port to attact a shop vac. Failing that it will take two people to hold a vac hose near the cutter. Once I have the plaster cut I don't have a problem burning bits on the wood lathe. Don't touch the plaster!!!! Same as a momentary dip in the dirt with a chain saw. Your Done!!

 

[jwjrw]

I've been getting more and more jobs in houses with old wood lath and plaster. My method has always been to use a Rotozip with a tile cutting bit (I use the 1/4" bit hoping it will last longer than the 1/8" bit) to cut the plaster and then use a wood cutting Rotozip bit to cut the lath. Sometimes I burn the wood cutting bit up in the lath even if I go slow. This is a long process and the dust travels EVERYWHERE which isn't the customer's favorite thing to see.

What do you guys do? Tips or tricks appreciated!

Are you talking installing boxes where just wires are now? Asking because I just did 5 in a 1870 house. Half K&T half newer romex. No boxes in the ceilings on 1st floor. I sread a dropcloth took my roto zip and vaccum cleaner hose up the ladder and went at it.

 

[jzadroga]

I also use a rotozip with a tile bit. But I use the tile bit on the lath as well. First I cut the plaster and knock it away. Then I use the bit to cut the lath slowly. I find there is less chance to burn out the tile bit with the wood.

I have also just purchased a Fien Tool. I have used it with a grout bit to cut into some very hard plaster. Then the wood blade to cut the lath. There is a lot less dust and following a straight line is very easy. I do have to remove some of the plaster in the corners by hand or I could roto zip that part as well. My employee loves the Fein tool as he butchers the plaster otherwise. (porbably saved his job).

 

[rich000]

I have the Craftsman version of the Fein tool. WHY? Because it is cordless. It is a very useful tool. The tool is only $99. Extra battery is $25. Flush cut blades are (2) for $12.

Yes the Fein is also a great tool. I wanted to try the Craftsman to see how it would work. I am happy to say it works quite well.

It is great for cutting in boxes, trimming 2x4's to get a box to fit, and just general cutting.

Plaster will chew up the wood blades, so yes, use a tile blade.

 

[rich000]

Oh, the Craftsman also has a vacuum port. I rarely use it though since it doesn't kick up a lot of dust.

 

[kbsparky]

You have to use a good shop vac when roto-zipping, or else the dust will be everywhere. The accessory head can be bought separately, with a nozzle for your vacuum hose:

 

[jjhoward]

We outline a square for the box with a drill 1/4" or smaller (many holes) then even off the edges of the plaster with a razor.

The wood lath is a PIA. We drill through the lath then snap off with needle nose.

The roto zip lost favor with us. We couldn't get the bits to last.

 

[NewOnMyOwn]

Hey guys, thanks for the replies.

I kinda lied in the first post to make it easier, I actually have the Dewalt version of the Rotozip, not the Rotozip brand. Because of that, the vacuum attachment doesn't fit (I bought one and had to return it).

However if the Rotozip method is what you guys think is the best tool, I'll go buy a Rotozip brand model and vacuum attachment.

jzadroga, that's interesting that you use the Tile bit for the wood lath, definitely easier than changing out hot bits halfway thru the job. The wood lath doesn't dull the tile bit? Anyone else have any experience with this method?

 

[rt66electric]

old fashion way

old fashion way

Ive allways used the 1/4 masonary drill bit through the plaster and sometimes through the lath. After the holes are cut and the plaster is knocked away, I use a hacksaw blade to cut through the lath. I have found through trial and error it is best to cut 7/8 of the way of both sides of openning before finishing a final cut, it keeps the lathe from slapping away from the hole. Vertical spacing between the laths can vary for house to house for a cut-in box. I usually remove 2 1/8 laths, to remove 1/8 of a lath, make two vertical cuts with the hacksaw blade and split off the middle with pliers.

 

[NewOnMyOwn]

Hey guys, I was hoping to use those Smartboxes in plaster this way the box is supported by the stud and not the (possibly) loose plaster and lath.

What ways do you use to find the stud in plaster and wood lath without making holes?

Thanks again for the help!

 

[jaylectricity]

Hey guys, I was hoping to use those Smartboxes in plaster this way the box is supported by the stud and not the (possibly) loose plaster and lath.

What ways do you use to find the stud in plaster and wood lath without making holes?

Thanks again for the help!

If you can't get a studfinder to work, (I know it's really tough with all the wood crisscrossing the studs) you can try taking a look at the baseboard. Usually every 16" (or 14" in some of these old houses) you'll notice small dimples in the paint where they drove in finish nails to keep the baseboard in place. I usually find them along the rounded top edge of the baseboard and they usually show you where the studs are.

Another way is to find another electrical box that is most likely mounted to a stud on the wall, or on the other side of the wall and measure from there.

I've done a lot of work on that kind of wall. I used to cut in metal old work boxes which was a pain, but those smart boxes are the way to go now. One thing I would do is draw an outline of the box I wanted to cut in. Then I would use my flat head screwdriver to gently punch out the plaster along my line. After you complete the outline you can just punch the middle plaster away. This is useful if you are just cutting in one box and don't want to carry yet another tool from the truck.

 

[jaylectricity]

Oh yeah, and a keyhole saw would cut the lathe. cut one side until there is about a 1/4" left to go, then do the other side. This way you're not pulling the entire piece of lathe back and forth once you've cut one side free.

On second thought, just go get that rotozip with the vacuum. :grin:

 

[danickstr]

for ceiling cans, the Lenox type 6L carbide hole drill followed by the wood drill works well for me, and I blue tape up a piece of painters plastic 3/4's of the way around the mess and stick my hand in the open hole, then hold it closed as I drill. sort of like the salad bowl approach, but I can throw it away afterwards.

For boxes in walls, I drill the corners and use a jigsaw with a carbide or regular blade, taping up the wall with blue tape to glide on. Those roto-zips annoy me with their whining and dust whirlwind. Plus finding a tip is not always easy.

 

[LarryFine]

I have found through trial and error it is best to cut 7/8 of the way of both sides of openning before finishing a final cut, it keeps the lathe from slapping away from the hole.

cut one side until there is about a 1/4" left to go, then do the other side. This way you're not pulling the entire piece of lathe back and forth once you've cut one side free.

One more thing to be wary of: If you're not careful, it's possible to push half of a slat in where you're working, and pop out a hunk of plaster on the other side of the stud due to the slat see-sawing.

Don't ask me how I know. :roll:

 

[electricguy61]

I use a small grinder w/ a diamond blade for cutting plaster & stucco.

Lot's of dust, so we use a shop vac right alongside.

Faster & cheaper then the rotozip blades that constantly break & burn.

 

[NewOnMyOwn]

Thanks guys, definitely a big help.

One thing that I noticed when I switched into the residential market is that plastic old work boxes are considerably bigger than metal gem boxes. Because of that, there is less room for error, unless you want to use an oversized plate that doesn't match the other ones.

 

[aline]

Here's a video of the fein multimaster in action on tile grout.
There are cheaper versions of this tool on the market as well.
http://www.fein.de/fein-multimaster/us/en/media/multimaster_video.php?vidname=muma_05

 

[dmagyar]

Fein Multi-master

Fein Multi-master

MeOnMyOwn, I use a fein multi-master for cuts into sheetrock or plaster and lath. I use the older blades for the plaster and newer to cut through the lath. I recently purchased a Festool vacuum for keeping the dust out of the air. The roto-zips just put too much dust in the air, but I admit I didn't have one of the dust attachments.

 

[realolman]

......(I use the 1/4" bit hoping it will last longer than the 1/8" bit) to cut the plaster and then use a wood cutting Rotozip bit to cut the lath. Sometimes I burn the wood cutting bit up in the lath even if I go slow. .

Just a thought... @ the same RPM, the outside edge of the 1/4" bit would run twice as many feet per minute as the 1/8" bit.


I don't know if it's possible that the larger bit would burn up quicker or not. Might be worth a try. Also the smaller bit wouldn't remove as much material (dust )


Do those Fein type things blades last very long?