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.