I am making a soundproofing partition just inside a bathroom brick
wall, not attached to it, and to save space, the partition is to be
solid 18mm plywood with no battens. Wall area is only about 2.5 x
2.5metres.
I want WBP plywood, but I can see softwood and hardwood ply at very
different prices. I need the plywood to be very stiff since no
battening is involved. It also needs to be very flat, and to not warp
or bend, since it will be tiled on. I may also clad with a cement board
before the tiles. What's the best ply to use ? Good suppliers ?
Cheers,
Simon.

sm_jamieson wrote:
I am making a soundproofing partition just inside a bathroom brick
wall, not attached to it, and to save space, the partition is to be
solid 18mm plywood with no battens. Wall area is only about 2.5 x
2.5metres.

Hm. Not at all sure about that. What's on the other side of
the wall? Won't a 2.5m square (how do you join it?) of ply
act like a giant wobble-board?

The message .com
from "sm_jamieson" contains these words:

I need the plywood to be very stiff since no
battening is involved.

That's taking quite a chance over a 2.5m span. Personally I'd get busy
with the battens.

--
Skipweasel
Pay no attention to that man behind the curtain.

The message .com
from "sm_jamieson" contains these words:

If 18mm ply is not stiff enough, is there any other board suitable ?

Ah, right, now I see what you're trying to do.

You could get away with 3/4" ply if you could stiffen it. A welded steel
frame would do nicely, 2" box round the outside, 1" angles running side
to side, with some steel noggins welded in between, the whole thing
screwed to the back of the ply.

Or - you could cut long strips of ply and glue then on edge to the back
of the board - if you could stretch to making the whole thing 3" thick
instead of 2, that'd stiffen it up a lot. Particularly if you ran them
crisscross interlocking.

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message .com
from "sm_jamieson" contains these words:

If 18mm ply is not stiff enough, is there any other board suitable ?

Ah, right, now I see what you're trying to do.

You could get away with 3/4" ply if you could stiffen it. A welded steel
frame would do nicely, 2" box round the outside, 1" angles running side
to side, with some steel noggins welded in between, the whole thing
screwed to the back of the ply.

Thats the kind of idea.
Edges will be screwed to battens anyway. Some kind of steel structure
sounds a good idea.
Cheers,
Simon.

sm_jamieson wrote:
The requirement is for a "camden partition" only 50mm
deep in all, in front of a normal 9" party wall.

What's on the other side of the wall, that can be heard
through 9" of it! A jet engine being tested?

Chris Bacon wrote:
sm_jamieson wrote:
The requirement is for a "camden partition" only 50mm
deep in all, in front of a normal 9" party wall.

What's on the other side of the wall, that can be heard
through 9" of it! A jet engine being tested?

You're curious now.
Its partly an experiment, since I'm doing the bathroom back to brick
anyway.
I'm a bit paranoid about the odd noises you get from next doors
bathroom, usually only audible a night. With a 9" wall, if someone is
sitting on the loo right next to the wall and, coughs or blows the old
nose, it can be heard. It unsettles me !
So I'm trying to make it totally silent. Thus a gap, some mineral wool,
some heavy boarding etc. Bathroom not huge, so needs to be a slimline
as possible.
The jet engine ?
Well, the overhead cistern I am removing does a fair impression of one.
As an aside, my (to be removed) chinawear has gone rusty ! I cut the
old cast iron bath into 3 with an angle grinder, and the iron dust that
had landed on the damp sink and loo went rusty almost before my eyes,
and somehow worked its way into the glaze. It can be removed, but with
a lot of elbow grease. I tried cracking the bath with a lump hammer but
nothing was happening, and the lady next door thought her time had come
!
Simon.

The message .com
from "sm_jamieson" contains these words:

I'm a bit paranoid about the odd noises you get from next doors
bathroom, usually only audible a night.

Can't you ask 'em to go easy on the beans?

I'd have thought most of the noise would come from the windows, anyway.
Certainly what happens in our terrace - in warm weather when everyone's
got their windows open you can hear bathtime gurgles all over the place.

--
Skipweasel
Pay no attention to that man behind the curtain.

On 13 Jun 2006 03:39:12 -0700, "sm_jamieson"
wrote:

I am making a soundproofing partition just inside a bathroom brick
wall, not attached to it, and to save space, the partition is to be
solid 18mm plywood with no battens. Wall area is only about 2.5 x
2.5metres.
I want WBP plywood, but I can see softwood and hardwood ply at very
different prices. I need the plywood to be very stiff since no
battening is involved. It also needs to be very flat, and to not warp
or bend, since it will be tiled on. I may also clad with a cement board
before the tiles. What's the best ply to use ? Good suppliers ?
Cheers,
Simon.

Hi,

Why ply? It's very strong but not that stiff, or dense. Something
heavy like moisture resistant MDF or a cement board like Fermacell
should be better. If space is tight a layer of heavy rubber like
stable matting could be used to damp vibration and resonance.

Check out what high end speakers are made out of, ply would be the
last material to use. Plenty of info on soundproofing out there on the
web too.

cheers,
Pete.

sm_jamieson wrote:
I am making a soundproofing partition just inside a bathroom brick
wall, not attached to it, and to save space, the partition is to be
solid 18mm plywood with no battens. Wall area is only about 2.5 x
2.5metres.
I want WBP plywood, but I can see softwood and hardwood ply at very
different prices. I need the plywood to be very stiff since no
battening is involved. It also needs to be very flat, and to not warp
or bend, since it will be tiled on. I may also clad with a cement board
before the tiles. What's the best ply to use ? Good suppliers ?
Cheers,
Simon.

Use Fermacell board for soundproofing, rather than messing about with
trying an unconventional ply construction.

dg