Guys,
I'm a small 2 man shop that does small home theaters, plasma hangs, and whole house audio. This morning I went to quote a simple 5.1 system for a TV and a 3 room in ceiling audio system. The question is what is the easiest way to cut out for my 3 pairs of in ceiling speakers? I normally use a adjustable hole cutter with dust tray by Labor Saving Devices, in drywall works great, this house was built in the 20's and has about 1" of plaster with metal screen in the center. I know my hole cutter won't work, what do you guys use?

I hope you're well insured as plaster can crack/crumble from wall to wall. I have used Dremel with reasonable results but, you will eat through bits like crazy.

Razor knife (replace blade often), and tin snips for the screen.

Take your time, careful cutting the mesh, as being rough will affect the surrounding plaster area.....Also have a plaster repair person in mind when your doing this.

These take a lot longer than normal.

Mistakes happen and the crack can "walk" across the ceiling.

Good luck

CI

First, make a hole (about an inch in diameter) in the center of where the speaker will go. This does two things: It allows you to check around for joist or rafter locations AND when working with plaster, cracks will tend to head towards this center hole and not in the other direction.

To add onto this, after you make the hole take a coat hanger and bend it to the Radius of your speaker. Put it up in the hole and spin it around to make sure you clear any obstructions. If it's all clear then take a utility knife and use the blade to score the plaster. Do this slightly outside your cut line so that you don't have to go back to ream out the plaster. Any reaming could cause the plaster to crack or bust out. Then use a keyhole saw.

Otherwise rotozip with someone holding a vaccum when your cutting.

Good luck!

My suggestion, if the home owner can stomach it, use square speakers. Use a grinder and cutting wheels to cut as much of the straight line as you can without going outside the cutout. Use a dremel to finish the parts where you couldnt get all the way to the edge. Tape painters plastic to the ceiling sround your ladder and let it drape the floor, encase yourself, it will help with clean up. let the dust really settle for 30 minutes or so before removing the painters plastic. Dust suit, mask, and eye protection!

What I have the best luck with is, after checking for obstructions. Trace out the template, use a small masonary drill bit and drill holes around the pencil line, all the way around. Then you can use a razor knife or drywall saw and cut the remainder of the plaster out. This takes some time, but I have not had a plaster crack using this method. A second guy with a box and a vacuum is always a good idea.

This is exactly what I was going to suggest. I agree with others to first drill a hole in the middle and check for joists or other obstructions first, but as far as actually cutting, TBD Brian is correct that this works well and shouldn't cause any cracking.

AFun times ahead. I do a combo of what has been mentioned. Cut a hole in the center. Make sure it is clear. I use a roto zip with the fat tile bit to nibble away at the plaster. Make a few passes until you get to the mesh. Then snips to cut the mesh. You should be able to clean it all out to the wood....you did not mention if there is slats above the plaster? If so, rotozip again or sawzall....be careful. The biggest thing is to make sure the client understands that there is a chance of some collateral damage. And put a huge drop cloth down and drape the plastic all around you. Cleanup is a beeyotch!!!!


Also, I agree with the cutoff wheel idea. It is much faster and easier. But hard to do circles. :)

Everybody is talking about using a vacuum while cutting so I thought I would throw this in.

I bought a Aquair Filter for Homer's Depot a while back. I love it!

[Link: sandkleen.com]

I took off the sanding head and taped the hose to my rotozip (right beside the bit) when I'm doing drywall or plaster. I also use a hepa filter in my shop vac. It keeps my vac from getting clogged up with drywall dust. Very nice addition to the van. Everything fits nicely into the 5 gallon bucket when done.

I'd do two things...

1. Use a multi-tool & spec in square or rectangular speakers.
2. Charge by the hour (and figure extra clean-up time)!!!

I couldn't have explained this any better.  This is exactly the way I do it.  I use a 1/2" masonry bit and keep it on the inside of the line.  I drill holes all the way around so that there is only about an 1" of cutting with a drywall saw before I get to the next hole.  Like Brian said, it takes a bit longer but I've never had an issue with it.  

Like the others said prior.  Pop a hole in the center to make sure there isn't any obstructions.  

Are you EPA Certified. [Link: epa.gov]

If you are working on a building built before 1978 you will need to be certified.

Man, you guys are smart!

From what I read above, everybody who has written has done this before. They mention all the problems you can run into. I've only done this with around eight holes in my life, and they were the worst jobs I've ever had to do. Ever. That includes crawl under the house with silt and water under it, where I weighed twenty pounds more coming out, because of the mud caked up to my knees, and I had to get naked in the orchard to clean off. Did I say -- remember to bring a change of clothes?

You guys have improved on what I learned! Contain the dust and don't breathe it, ever.

It's REALLY important to use that coathanger or whatever to be sure your plan doesn't run you into wood. And don't draw any kind of outline on the ceiling until you've done that. There is NO WAY to totally remove any kind of ink or pencil from a ceiling.

And oh yeah -- the first time I did this, I was working for a guy who told the homeowner in advance that there is often more damage around the hole than there is hole with this kind of construction. He has to relax and know that it will be patched and painted. (Then you have to be sure to charge appropriately for that.)

A couple of points.
I'd allow a couple of hours for dust settling if possible. Also it's worth noting that this plaster may well crack slowly over time with speaker vibration. It's quite possible you could get a call in 2 years because it took that long. Your client needs to know in advance that this may be a problem and fixing it if it happens is at his expense.