New holes in old plaster for electrical
joeshome3
| Posted in General Discussion on
Hello,
Updating the electrical. removing the knob and tube and installing new receptacles and switches.
What are the easiest, quickest and neatest ways to make new holes in the old, dry plaster? The Rotozip bits I have found wear out before finishing one hole. I need to make 15 new holes.
Thank you,
Joe
Replies
If you're talking about holes to snake wire, I use a sharp blow or two with a framing hammer. The rotozip is good for the lath (assuming you got wood lath). No point in being too dainty about it.
If you're talking about holes for new receptacle boxes, score the plaster as best you can with a sharp utility knife and use the hammer -- just be a little more ginger about it. Rotozip the lath. You'll have a little patching to do, but no matter haw you make the hole, there's always at least a little bit of patching.
I've seen people do it with the dry diamond blade in an angle grinder, but that can get pretty dusty.
Guess it's your preference for how you do it. I've gotten pretty good at plastering, so I don't spend a lot of time making the holes.
"Let's get crack-a-lackin" --- Adam Carolla
use the tile cutter or backer board bit for the rotozip...
if you smack a plaster wall with a framing hammer all kinds "I really wish that hadn't happened" will happen...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
if you smack a plaster wall with a framing hammer all kinds "I really wish that hadn't happened" will happen...
I hear ya, but I tend to do it on a mass scale. If I'm too ginger about, all kinds of "where'd the day go" stuff happens. If the existing plaster is still tight to the lath, I've had good luck with popping a hole with a sharp blow without breaking adjacent keys. But like I said, I've gotten pretty good at plastering (and not necessarily by choice). ;-)
"Let's get crack-a-lackin" --- Adam Carolla
what happens when you oscilate the lath with that BFH and....
me... I rather not go there....
broken plaster = repairs...
repairs = painting...
painting = I AM NOT GOING THERE NO MATTER WHAT!!!!!!Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
>>"what happens when you oscilate the lath with that BFH and.... . . . I AM NOT GOING THERE NO MATTER WHAT!!!!!!
OK, OK, you have a point. If the blow isn't sharp, the lath will move and a big chunk of the plaster succumbs to gravity, or you just get a big nice expansion crack when the plaster has to move out of the way to accept the hammer tearing through it. Maybe the risk isn't worth the reward. When I do it, the plaster under the hammer head tends to pulverize, but I won't lie and say I've never had an "oops" moment or a crack longer than I 'xactly intended. I prefer fixing the plaster to being real careful with the holes 'cause I find I have a lot of repair to do anyway for a rewiring job. Just my preference. ;-)
OP, listen to IMERC. If you do it the way I suggested and luck isn't smiling on you, you will lose a good chunk of plaster off your wall. Maybe you don't want that. ;-)
PS: just occured to me why I usually have a lot of repair to do anyway for a rewiring job. ;-) Still hate the dust from cutting. I can taste it just thinking about it. Better vac? ;-)
"Let's get crack-a-lackin" --- Adam Carolla
Edited 4/17/2006 1:11 pm ET by philarenewal
are you the kind guy that passes up on the sawzall with the "Mega Death Terminator" blade for the Sthil 99.089 with the nothing is safe in this nieghborhood chain????
I never did DW till sometime in the middle to late 60's... 10 years or so prior to that it was wood or rock lath and plaster... I'm stil good at it and can match most work out there... but why???
the root thing here is I don't need to paint or even have to dicuss painting when I'm done...
repairs are cake and pie... but why do it if ya don't have to???
depending on the lay up.. diamond bade or a gorrilla bit in a rotozip... a hammer can cause the paster to pop loose half way down the wall (that you won't see right then) and it cracks or just falls off untill sometime in the future...
can we spell call back...
tip of the day.. don't use your coffee bean grinder to grind coco beans... uck...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
are you the kind guy that passes up on the sawzall with the "Mega Death Terminator" blade for the Sthil 99.089 with the nothing is safe in this nieghborhood chain????
Yup. But my last demo job I burned up the chainsaw (had smoke pouring out of it), so had to go back to the (boring) sawzall for the duration. Takes all the fun right out of it. Now if they'd only make a chainsaw blade that could slice nails without consequence, that chainsaw would travel to every job. ;-)
>>"but why do it if ya don't have to???
OK, OK, you convinced me.
Next time I will try your way. You have a convert. ;-)
"Let's get crack-a-lackin" --- Adam Carolla
I have had to put loads of new outlet boxes, switch boxes, etc., in our old real-plaster walls. Here's my approach: With a carbide tipped bit in my drill, drill a hole near where the center of the box will go. With the drill running, move it up and down, enlarging the hole, until it goes through between the lath boards. Where it goes through will end up being where the box in centered vertically: at least on my walls, the lath are spaced so that I remove completely the one above and the one below the center hole that I just made. The mounting ears of the box then screw to the lath that are one above and one below the one that I removed (may have to make those last two lath a bit narrower to get the box inserted --- use manual keyhole saw). Reverse the ears so the box protrudes far enough to be flush with the wall surface, screw it in (drill pilot holes or lath will split). Oh yeah, pull wire in before screwing in the box! I must have put in 50 to 100 boxes this way. A little mud or plaster closes up the small hole around the box.
Bob Chapman
use the dust pick up attachment gizzmo for the rotozip and hook it to your shop vac... Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
First off let me tell you I am NOT and electrician, as you can see by my screen name.
I do a lot of work in older homes with plaster and lath. Usually after new electical is installed we are left to repair the damage around new boxes. One electrician was using a hand grinder to cut the hols perfectly. No shaking the plaster away from the lath. Perfect edges, little dust keeping a vacuum by the cutting wheel and no damge for us to fix.
He said he saw a guy on This Old House doing it this way.
Good luck,
Jon
I've done about 50 new outlets in my old house, and they best I've found is to use a template out of MDF, etc. taped to the wall, drill a couple holes and then use a sharp jigsaw blade to slowly cut the hole. Holding a vac close as you do all this helps a ton. Tried the spiral bit in my router, worked terribly, was way too dusty and awkward.
I also went around with a little setting compound to even out some of the inevitable cracks and chips. Used a razor blade to remove small bits for a tight fit.
PJ
Just for your info, there are two types of spirals -- left and right. One (forget which) is intended to blow the crud into the wall cavity, while the other pulls it out. The standard DW bits blow in, but the ones for tile/plaster pull out. If you need to control dust better you may want to try a DW bit, even on plaster.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
I have the "up" spiral bit, never heard them referred to as left and right though. I figured the more rpm, the more dust, so I abandoned the idea quickly. A good sharp jigsaw blade worked well, you just go through them pretty quick. Still cheaper than a cheap spiral bit.
PJ
He's usin a jigsaw on a plaster wall. . . .
I'd rather the chainsaw. ;-)
Waddaya think?
"Let's get crack-a-lackin" --- Adam Carolla
I'm so fond of plaster... let's make it plan "B" before Mr T gets here with plan "A"...
I tried to find an old CS demo chain FYI.. we cut CC, rebar, CI, PVC, copper anything, rigid pipe, simpsons, steel window casings, steel jambs, any kind of roofing and, and, and....
I'll keep looking...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
T uses plan N
- napalm
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I saw this thing at a toolstore, very stout, and very $$$...the chain was over $500, but the mfr. listed demolition under uses. http://www.partnerusa.com/..
.
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'Wer ist jetzt der Idiot?'
that's us....
It'll do more than advertised...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
you got one?.
.
.
'Wer ist jetzt der Idiot?'
yes ... I'm not the owner... Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
is it as badazz as it looks ?.
.
.
'Wer ist jetzt der Idiot?'
badder...
think we now have two choices to cut those holes in OP's plaster???Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
Yeah, the fire departments around here use a chainsaw with a special demo blade. It has guards for the teeth that will knock nails, etc out of the way. They can cut straight through several layers of asphalt shingles with the thing.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
(Actually, a mini chainsaw would make sense for plaster demo. Less vibration than a recip, would be able to make shorter cuts than with a circ saw, the right chain design could probably handle just about anything in the way of cement plaster, wire lath, etc.)
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
I like the idea of a itty bitty chainsaw,
just one more goofy tool too ownand that Partner chain was Diamond impregnated.....at least I thought it was,Crap the whole damn saw was almost $2K.
.
.
'Wer ist jetzt der Idiot?'
An alternative to taping a template to the wall is to put painters tape on the wall and hot glue the template to the tape.But if the template is staying in place for you with tape, and you are not pulling paint off the wall - that's great.As to the original question, it is best (if you have wood lathe) to end up with an intact piece of lathe at both the top and bottom of the hole, presuming you are using old work junction boxes. By intact, I mean a notch out of each piece of lathe. This allows the 'ears' something more solid to grab onto. The best way to do this is to remove the plaster first, starting with just a small section, and see where the lathe lines up regarding your junction box.If you use any type of reciprocating blade, sooner or later it will grab a piece of lathe and shake a big section of plaster loose from the wall.
Just regular painters tape changed every other hole did fine, the hole itself took a few minutes, then I move on.
Never paid much attention to where the lath was. I've found that a really good sharp jigsaw blade won't rattle the teeth out of the wall like you mentioned, as long as you move slow. Using the orbiting action on my Bosch helped too.
Once in awhile I'd have to trim back the little flaps on the old work box so I could get behind a thick piece of lath/plaster, or at least back out the screw to the last thread to get the most possible depth.
PJ
I went through dozens of demolition blades removing 50 year old wire lath plaster. It was like trying to break out of jail. I tried a diamond blade on the circular saw...nearly killed the bearing in the saw and myself with the cloud of dust it generated. I new there had to be an easier way. I found this
http://www.hitachipowertools.com/product/files/specs/728795.jpg_prod_mx.jpg
This carbide grit blade will cut for hours. It leaves clean lines and a moderate amound of dust. I am unsure about wood lathe but can guarentee you that this works like all get out in wire lathe. They make them for jig saws too. They are also sold under the name remgrit at HD...Lowes carries the hitachi brand.
PS...you have to drill a starter hole
>>I went through dozens of demolition blades removing 50 year old wire lath plaster.
If you're talking about plaster demo, this works pretty good too. Often faster than cutting:
View Image
[pic of a sledgehammer] ;-)
I think the OP is adding some wire and boxes. Not demo.
"Let's get crack-a-lackin" --- Adam Carolla
Edited 4/17/2006 4:11 pm ET by philarenewal
That sledge hammer doesn't work so well when you are trying to preserve adjacent walls.
The carbide grit blades work well for all tasks, including cutting out openings for electrical boxes.
Don't get riled. I'm partly joking. ;-)
Using a sledge by poking it at the wall to break the plaster rather than wacking away at it can actually be pretty precise.
Your carbide blade to cut the interface between what goes and what stays in a steel lath wall is just the ticket there.
"Let's get crack-a-lackin" --- Adam Carolla
I am not riled...wire lathe plaster is an entirely different animal than wood lathe plaster. without a cutting tool it becomes a exercise in frustration. wire lathe and plaster is one badass combination
you know what is really nice about the blade. you can remove the plaster in sheets instead of piles of rubble. run the blade down each side of the stud bay, knock a hole in the side with a hammer to cut across the bay...and you have nice 14in X whatever size you want sheets ready to carry out.
what is really nice about the blade. you can remove the plaster in sheets instead of piles of rubble
That is nice -- if you're doing surgery. ;-)
If you can't tell from some of my previous posts, I'm no gentleman when in demo mode (or the rest of the time either). ;-)
(this is all tounge in cheek if you don't know me so good already)
"Let's get crack-a-lackin" --- Adam Carolla
Make two passes with the Rotozip.
1st pass is a carbide bit set to cut the plaster. It works very well, but the carbide bit is lousy on wood.
2nd pass is with a wood bit to cut the lath. Sort of slow going, unless you have two Rotozips, but it will give you a real clean hole. You could use a dremel for the lath cut and keep the Rotozip setup for the plaster.
Rotozip has an accessory so a shop vaccum can be used to get all the dust up, it works pretty good.
Beware of any reciprocating sort of saw, they tend to set the lath a flopping, which tears up the wall. Makita makes a small circular saw of about 3" diameter. If you can get a blade that will cut the plaster, this will work also. But with a lot more mess than the Rotozip.
You can have them cut well, or quick, but not both.
So no one uses a Ultra high pressure Hydrofluoric acid cutting jet?
Edited 4/17/2006 5:33 pm ET by MarkH
So no one uses a Ultra high pressure Hydrofluoric acid cutting jet?
Used too but my doc told me my calcium levels were getting too low from the splash. Had to stop. ;-)
"Let's get crack-a-lackin" --- Adam Carolla
So no one uses a Ultra high pressure Hydrofluoric acid cutting jet?
not that I know of... but I did get my hands on a water lazer fer a week un chaperoned...
ewwwwww baby.....
cut the wall rebar back fill 4' solid granite and french drain in a wink of an eye like it wasn't even there...
guess I had it turned up a might too far on that one....
cut over 200' of trench in solid granite in abot 5 hours...
back cut the trees from the house and resawed them into lumber or firewood.... 36" doug fir..
cut a 24"WF into manageable pieces... drilled bolt hoes in the same..
cut up a F350 into nothing....Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
I did get my hands on a water lazer fer a week un chaperoned...
Man, I NEED one of those!
when I played with it at first you could turn it down till you would THINK you drink from it like a water fountain but even then it was cutting rocks and RR ties like nothing to it...
full power was awe inspiring.... nothing withstood it...
using it for resaw gave ya dead nut 4s product...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
For a gag, could you loan it to somebody and tell 'em it's a pressure washer? ;-)
How about a make/model/website?
-- J.S.
it's mounted on desert sand colored transport / hauler truck... big mother at that...
and comes with an articulated arm....
Capnmac will know it...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
I cut the plaster with a diamond blade hand grout saw, from a tile place. Then carefully break out the middle of the plaster, exposing the lath. It's quick and easy enough, completely cordless, and you never have to recharge the batteries. Sometimes doing it by hand is the best way, especially if the potential for damage is an issue.
Then I cut the wood lath with the 3" battery Makita circular saw, much less damaging vibration than any recip or jig saw. For a single gang, cut both sides, then a few kerfs towards the top and bottom, and break out the little pieces. For two gang and up, you have room for the circular saw all the way around. Be sure to relieve that first vertical kerf, or it might bind up and do some damage.
-- J.S.
The best way I've found for cutting holes in lath plaster is with my multi master, I take a worn out blade (one of the ones with the Japanese style teeth all knocked off)and cut some new big teeth in it with a saw file, about 4 or 5tpi works well.
For best results give it a retouch after every each hole and it'll cut the plaster and lath in one pass without chipping the surface.
Easy way with existing tools:
1/4" masonry bit. Drill until you hit the wood lath in the pattern of the old work box you want to install. With bit through the gaps in the lath, tilt bit to cut along the line you want. Drill wood lath with twist bits or try cuting with jig saw, but this can lead to ripped loose lath as others have said. Drill some holes in the lath and then follow with jig saw or hand saw. Holes are not as neat as diamond blade on a grinder, but they can be servicable if you get the hang of it, and a lot less messy than diamond blade in grinder. I have used this masonry drill method to put in can lights overhead and used pie plates and other things as dust catchers to keep the mess down and plaster out of my drill.
Frank DuVal
You can never make something foolproof because fools are so ingenious.
I have done a lot of electrical upgrades in wire lath walls lately... Here's what works well. Mark out all openings,use a 1 inch paddle drill bit in two opposing corners, then a carbide sawzall blade to cut out opening. Cleaner than rotozips and very accurate. I can get 10 to 15 holes out of a single drill bit and the cut with a sawzall type blade is very straight and requires minimal patching. Iburnt up many roto blades in the wire, this is more cost effective given time involved thru finish. Tim