View Full Version : Plaster Cutting 101

09-26-2005, 10:16 AM
How do you all cut plaster walls for vents or electrical boxes, etc? I've tried the following options.

Drill series of holes in a line and cut out between holes -- works well, doesn't damage surrounding walls, kills drill bits, takes forever

Sawzall -- fast, sometimes pulls out large chunks of plaster around wall and breaks/loosens lath

repeatingly Score with a knife -- best result if knife doesn't get away from you. Takes forever, go through a few blades, arm gets tired

Drywall saw -- hard to get started, can damage lath like sawzall, gets stuck

Any other idears?


09-26-2005, 10:25 AM
I use a RotoZip rotary tool (basically a Dremel on steriods) with the angle wheel attachment and a cutoff wheel. You can be fairly precise with this, as I have trimmed rough edges off demo'd plaster walls where they need to meet up with drywall. Lots of dust and noise, but it doesn't take forever and you can make a clean cut if you take your time. Cuts through plaster, lath, and wood with no problem. If I had to do what you are describing, I would reach for the RotoZip.

Another idea would be to use the RotoZip with the masonry cutting bit. Similar concept but with the cutoff wheel you are using it like a grinder, and with the masonry bit you are using it like a router.

09-26-2005, 04:54 PM
rotozip sounds good. havent tried it, yet. usually i hit it with the skill saw then finish top and bottom with a sawzall and a metal blade. dirty job but does it fast.

09-27-2005, 07:06 PM
Was in Home Depot tonight and saw that diamond blades are available for the RotoZip. That might be another option for cutting the plaster walls. Just an idea. I know for a fact the masonry cutoff wheel will do the job. I was just thinking the diamond blade might make less dust, but I have not tried it before.

09-28-2005, 09:11 PM
i just posted a similar question but i need to make long cuts (the entire length of the wall). for my job i was thinking either circular saw (can mount an edge guide to the wall and control depth of cut) or angle grinder w/ diamond blade.
for short cuts a masonry cutoff wheel will suffice but if it's more than a rare occurrence go for the diamond. not sure what'll happen if you try to use the diamond blade to cut through the entire thickness of the wall, lath and all. probably a better idea to cut and remove the plaster, then go back for the lath w/ a different blade/attachment.

09-29-2005, 09:59 AM
Another idea for long or many cuts is a masonry cutoff wheel in a circular saw. I have been cutting alot of cement board this way with great results. Set the blade depth and go. Cutoff wheels are cheap. I agree a diamond blade might not like the wood or metal lath. But the cutoff wheels will take out everything in its path, assuming we're not talking about ceramic or porcelain tiles.

A hammer and demo bar will also git r done. Depends on the specific room/situation. For precise cuts, I would go with the RotoZip/cutoff wheel. For lots of long straight cuts the circular saw with cutoff wheel. For stuff you don't know what's under there, knock a hole in the wall and sawzall a few inches at a time.