I need to cut out a 48″ by 48″ hole in the cieling of a clients kitchen. The house is around 70 years old with wood lathe and plaster. What is a smart way to cut this hole to get a clean cut and to minimize the mess. Thanx.
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You will need a lot of luck first, cutting lathe and plaster is a messy job.
First mark out the proposed hole, the take some 1 x stock and prop it with studs or jacks to the outside edge of proposed hole, then take your reciprocator saw and use the 1 x stock as a guide for the blade.
The 1 x stock will have prevented the lathes from ripping through the ceiling, leaving you with a reasonably clean hole.
Hope this helps
I'd be interested to see if anyone has a better idea, but if it wuz me, I'd be breaking out the angle grinder with a diamond blade and a shop vac to catch as much dust as possible. Score the outline, then use a hammer and flat bar to crack & ease out the plaster. Trim cut the lath last. Still, it'll be a mess. The biggest challenge is to keep the plaster from loosening up from knocking the lath around. Gotta be real careful with that.
That'll likely leave you with a bunch of unsupported lath/plaster around the margins tho'. My own preference is to NOT trim the plaster straight -- just bust a hole a little bigger than final size with a hammer & flat bar, with jagged margins. You can then trim the lath to size, install some framing to support the lath ends (which you can't really do if the plaster is still on it), and patch. (I prefer to patch jagged edges -- it's easier to hide the patch IMHO.)
Mike Hennessy
Pittsburgh, PA
Been there done that. I like the rotozip myself. To reattach the lath I wiggle blocking where needed and use plaster washers to reattach the loose ends.
Edited 11/10/2008 9:02 pm ET by ted
"Been there done that. I like the rotozip myself."
For a hole 4' square? For a J-box, yeah, but 16" of cut with a rotozip would take all day and burn up about 6 bits! ;-)
Mike HennessyPittsburgh, PA
No bits. Use the tile wheel it'll cut through plaster. Alternately if he could get an arbor adaptor he could plug in a 4" diamond wheel.
Before I had the cutting wheel and attachment I did once cut through about 8' of plaster. It was dusty and I did it in light passes. About 1/8" deep at a time.
"No bits. Use the tile wheel it'll cut through plaster."
Ah -- you must have the bells & whistles model. Mine lacks the wheel attachment, since I figure that's just a small angle grinder -- and I already have a couple of them, so I didn't spring for the accessory. So I think we're on the same page, only with different horsepower. ;-)
Mike HennessyPittsburgh, PA
Its a pita, but the cleanest cuts I have made in plaster & lathe are using a rotozip and two passes. The 1st pass is with the carbide bit to cut the plaster, then a 2nd pass with a wood bit.
Yes, you may want to attach a guide board, particularly for the 1st pass. Rotozip does have a dust catcher attachment, which helps.
Wear a dust mask anyway.
You will get a very clean cut, however.
Good luck.
I'd probably screw pieces of wood around the perimeter of the openning to reinforce the plaster. Then I would score the plaster with a knife (or even better get my helper to do it). Remove plaster with a flat bar or whatever. Then cut the lath with one of my japanese saws.
I figure the hand tools will make less dust etc. than the power tools would.
Covering everything in the kitchen and setting a fan to blow the dust out the kitchen window (with a plan for make-up air) is highly recommended.
Does the opening have to be exactly 48"x48"?
I little background on the project might help clarify the best approach.
Behind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people. [Theodore Roosevelt]
I've found an angle grinder to be the most effective way ... but it sure is dusty! Tent it off, use a respirator, and have a vacuum collecting the dust as you make it, as best as you can!
Once you've removed the plaster, then you can work on the wood. Here, do as much as you can with a circular saw; a reciprocating saw just shakes & breaks the plaster, making more trouble for you. Save the saws-it-all for the last corner cuts, and use a fine blade.
If you have to make small adjustments to the opening, "Paws Off" tools sells a rather pricey carbide grit file that fits in your saws-it-all, and works quite well.
Another tool that shows promise for this job is a Rotozip with one of the tapered bits they sell for working tileboard - but my experience is too limited to make a reccomendation.
Blue tape around the proposed cut. Adding a 1x just makes the stuff crack some more. Score cut with razor knife. Use small had held battery operated trim saw with depth set to about a half inch to complete score of plaster. Remove plaster gently.
Find ceiling joists and cut back more plaster to center or so of joists. Use trim saw with depth set at about a quarter inch to cut away lathe at center line. Remove lathe and use chisel to complete cuts if necessary. Re-attach other ends of lathe to joists.
Usual dust protection and tarps below cuts. Regards, Scooter"I may be drunk, but you're crazy, and I'll be sober tomorrow." WC Fields, "Its a Gift" 1934
I think in the past few days I saw someone mention using a Multimaster (or one of the knock-offs) with their carbide grit blade - usually used for cutting tile grout.
Might be a bit slower than the other options, but the dust should more or less just fall down rather than blowing all over the place.
Don
>>using a Multimaster (or one of the knock-offs) with their carbide grit blade<<I've done that pretty successfully. Their diamond blade works even better, but at 110 bucks it's a little pricey. Screwed a straightedge to the wall to guide the MM blade exactly.Would help to know what the end product needs to be. Are you looking for a very precisely sized cutout, our just a clean one with minimal plaster loss?Steve
i've had good luck with the angle grinder and diamond blade. if you can get some one to hold a vac nozzle as you go it will really help.
the peoblem with l&p is not shaking the plaster loose in what you want to save,my experence with a recip saw is ,it's a great way to rattle the plaster off.especially a clg.
if a man speaks in the forest,and there's not a woman to hear him,is he still wrong?
Milwaukee sells a plaster cutting recip blade that does a fine job of it.