"RogerT" wrote in message
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"zek" wrote in message
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On May 28, 6:31 pm, "RBM" wrote:
"zek" wrote in message

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On May 28, 6:13 pm, "RBM" wrote:

"zek" wrote in message

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my house has walls that are very thick and heavy. Cutting electrical
outlet holes and ceiling holes is very difficult. Using a saws all
with a big tooth demolition blade, I get maybe 20 inches before the
blade is flat. Ceramic blades are much worse. Am I doing it. Right?
I find finer tooth blades are worse.

Greg

What is the material that you're cutting? Other than outlet boxes, what
are
you cutting on the ceiling?

I have cut ceiling recessed lights and an attic entrance. The round
holes need a smaller blade which goes bad fast, there is no lath or
metal or wood. I'll see if I have a piece to take a photo.

Greg

I think what you have, is rock lath plaster, it's like a layer of 1/2"
sheetrock with holes in it, that's plastered over. The plaster keys into
the
holes. It winds up about an inch thick, and is often very hard. I usually
cut outlet holes in that with a hand keyhole saw. It's work, but you're
getting a clean rectangle with no big chips. For the recessed lights,
Lenox
makes carbide hole saws that work great. The only down side is the dust.
I
cut a basketball in half, and drill a hole in the center of one half,
slide
it over the hole saw, which helps to trap the dust and plaster particles.

Picture".........

http://zekfrivolous.com/wall/wall.JPG

Greg

+++++++++++

Wow, that's an interesting picture. I've never seen anything like that,
but I also never heard of rock lath plaster before.

In the picture, is the brownish top of the picture the inside of the wall,
or is it the wall surface that shows when standing in the room?

I own a property that was built in the late 1940's. It has regular
drywall/sheetrock throughout but all of the sheetrock is double layered --
two layers of regular 1/2-inch sheetrock. I don't know if it is true, but
someone said to me that they believe that sheetrock was a newer form of
finishing walls at that time and the old-timers didn't think 1/2-inch
sheetrock would be strong enough so they double-rocked everything. I
guess wall finishing was going through a transition in the late 40's and
early 50's. A house I grew up in was built in 1954 and it has what is
normal for today -- regular 1/2-inch sheetrock walls throughout.

**I've seen double layer sheetrock done in newer houses. The first layer is
nailed and the second layer is glued to the first. It's a clean smooth job
with no nail indents