"ashroyer" wrote in message
...

I'm going to be blowing cellulose in my attic today (renting the
machine).

Additionaly, I would love to add some sound-proofing to the wall
between the master bedroom and bathroom (standard 2x4 sheetrock wall).
Does anyone know if blowing cellulose in the wall would help in cutting
down the bathroom noise?

How would I do that? I'm guessing just make some holes at the top of
the wall and put the hose in there?

Andy


--
ashroyer

It will mitigate some of the sound (particularly high frequencies) but will
not be anything like sound proofing. Low thuds will get through just fine.
The density of typical insulation is insufficient to stop sound, it simply
contains too much air and moves around too easily. Anything dense enough to
stop sound will begin loosing insulation effectiveness. Closed cell foam
would work better for sound dampning but is impractical to install unless
the wall is open.

Packing insulation in the plumbing wall is not advised because if it gets
wet, it will get moldy (particularly cellulose).

Sound proofing usually requires several modifications to the wall structure
to be successful. Leaving that hole open at the top of the wall space will
actually reduce transmission of low frequeciues by allowing the air
compressed by one wall to escape rather than transmitting to the opposite
wall for example.

Don't waste your time insulating an interior wall unless it is easy.