Time to put the new wiring in my latest rental, the problem is that I dont intend to gut this one. I know this was recently discussed but whats the best way to cut the plaster & lath to get the boxes in with out shreding the walls?
Were starting this tomorrow. Running the wire shouldnt be a problem I just need a clean way to cut my holes.
Replies
Rotozip with a plaster bit on it set to depth to cut the plaster and then a jigsaw to cut the lath. Done hundreds of them that way.
We use remodel boxes. Trace out the hole, use a spade bit to drill out two opposing corners( stay inside the lines), Use a a recip saw with a carbide granual blade ( Hitacchi makes nice ones), now cut to fit. The spade bit should be 3/4 to 1 in. in size. Good luck and go easy, there wire hidin in them thar walls. Yes this burns up bits, but is faster than having to patch plaster. Tim
Thanks for the suggestions. I looked for plaster bits for the Roto tonight and didnt see any. I'll try both tools and see what happens. At least I dont have to worry about hitting any wires in the walls.
If you have hard plaster then the tile bit is probably what you want.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I think I have one. I'll try it.
Maybe its me, but have a bag of Durabond handy just in case.
Oh yeah, there will be durabond. We cut some today and it went okay, but between the cracks in the walls and this "retro wire" job there's some patch repair.
They do make plaster bits, I've bought them from lowes, home depot and even sears. The bits are a lot like a tile bit but more aggressive and come in a 1/4" shank. They aren't cheap though, $12 at $15 for one bit. They are thick so they tend not to break but they can get gummed up if you hit the wood lath so keep a baby food jar of acetone around a clean the bit when necessary.
good luck
day
EDIT:
Just looked on Rotozip's website and the bit is the Duracut DC1
http://www.rotozip.com/Shop/CategorySubBrowse.htm?IID=66586&BID=18&HID=188064
Edited 3/22/2007 9:55 am ET by restorationday
Must've just been the depot I was at. They didnt have any.
If you lack the RotoZip as suggested - you can just cut the whole mess with a jigsaw. Plaster is hard on the blades - maybe 2 boxes to the blade.
Have had best luck using fine tooth blades (hack saw type fine).
I have usually probed around a bit to find out where the lath is in that particular section of wall before cutting the box outline; lets you figure out the best elevation for the particular box. The fewer pieces of lath you have to cut, the less chance of major plaster blow outs. However you do it, if the lath catches on the saw blade and starts bouncing against the back of the plaster ............oops.
Covering the area to be cut with that blue painter's masking tape helps protect the wall from the saw foot.
Good luck!
Jim
Never underestimate the value os a sharp pencil or good light.
I use an angle grinder with a diamond blade to cut the plaster. RotoZip to cut the lath. The diamond blade does a great job on the plaster without chipping or grabbing a lath and breaking out more than your desired hole.
The grinder is a really dusty way to go so use a shopvac to catch most of the Plaster dust.
Your the winner! We used the grinder attachment on the roto then went back with a jigsaw to cut the lath. Now we just have to figure out how to get all the wires through. Luckily we have tall base moulding so if need be we can run behind it.
A tape measure with the end hook removed and filed or ground to a smooth radius makes a great fish tape for running wires in walls.
Just don't let it retract all the way!
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Thanks for the idea. It may come in handy.
If you mean remove the baseboard and bore the studs, you will still need to repair the plaster to get the baseboard to lay flat. However, they do make a replacement baseboard that actually has a channel in it for wire. I think it is plastic and designed for painting.The best way to fish most wire is either from below or above if possible. Use the long flex bits to drill holes. The one place this does not work is switch legs. There most often you have to cut a trench at the top plate.
Most places will be wired from top or bottom. I have three places in this house that have no access to either though.
I'll just bore holes and then shim behind the trim. Its all original trim and I dont want to replace it just to hide wires.
If you do many of these with any form of reciprocating type saw (and wood lath), sooner or later you the saw will grab a piece of lath and vibrate it until half the plaster comes off.
I use a multimaster on the lath. I cut the plaster with a utility knife. But if I had to do a bunch, I would make up a jig, hot glue it to the wall (or painters tape on the wall) and use a rotozip.
We've had some luck with the jigsaw. I agree a sawsall would shake the house down.
Yet another reason for the one tool I dont have yet.
We did make a jig but the roto was no good (of course I couldnt find the plaster bit).
Multimaster with the grout-cutting blade for the plaster, & E-cut for the lath. I only wish I had gotten my multimaster when I bought the house, instead of several years on!
Or the all-time favorite: shaped explosives.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
That appears to be what they used in a few spots in my house!
I'm now a fan of a minigrinder and diamond wheel for plaster cutting of all kinds. The lathe is best cut with jigsaw or fine toothed blade in sawzall at low speed.
Plaster can also be cut with the jigsaw and normal blades, but the speed must be kept slow to prevent burning the blade.
As for tough pulls through walls in inaccesible areas, that's a great excuse to put in an extra box or so to help drilling from spot to spot, especially near a corner.
There simply isn't anything close to a normal fiche/fish tape for ease of use and making the most challenging pulls. That's an entire post in itself.
Good fiching.
Beer was created so carpenters wouldn't rule the world.
I am in the process of rewiring an 1800s house with knob and tube being changed to romex, so I feel your pain! A good fishtape and a diversibit are a good investment here... There was a video on this site a while back with Clifford Popejoy using the diversibit. I am much more comfortable using that bit in a lath and plaster wall than with a sheetrock wall!