On Fri, 8 Jan 2010 14:07:32 -0500, "Jay-T"
wrote:

dadiOH wrote:
Jay-T wrote:

I understand the issues about sound reduction and the limited amount
that can be achieved without building detached isolated walls or
barriers etc. I bought the property as an investment and will be
renting it out. Since I am in the process of finishing repairs, I
thought maybe I could do "a little" to help make it a little quieter
for my next door neighbor by slightly cutting down on noise coming
from my future tenants.

Do the next door neighbors *say* there is a problem?

Yes. The neighbor menioned that while I am doing work on the house, if
there is anything that could be done to cut down the noise transmission
between the two properties, that would be great. He said that it is easy to
hear between the two properties -- that the sounds seem to go right through
the walls. He's right about that -- it does. He wasn't complaining, and he
was completely polite about it. He just said that if while I was doing the
work anything along those lines that might help would be great. I said I
wasn't sure what could be done, if anything, or what might work.

Since it is going to be a rental, I am reluctant to put any soft surface on
the walls -- such as acoutic tiles or whatever -- and my reading and
experience says that soft surfaces may not do much anyway. Soft surfaces
apparently reduce echo/in-room issues but don't do much for transmission
issues, contrary to popular opinion. For transmission issues, apparently
the best approach is using one of the isolated wall techniques, and the
second best option is increasing the density of the walls.

You wrote,

I ask because I
lived for 16 years in a condo. The walls between units were poured
concrete and each side had a layer of 1/2" drywall. I never heard a
sound from the neighbors.

I think that is the density concept at work.

In my case, the party wall is an old-time strange type of setup. They seem
to have created some kind of stud, lathe, and plaster-like combination wall,
and then just filled in the spaces using stacked mostly vertical (and some
horizontal) red bricks in between. It's not really a brick wall as in, lay
the bricks on top of each other with mortar in between, the way that a
typical brick wall is made. Instead, the bricks are just there filling up
the space with a few touches of mortar here and there. I never saw
construction like that before. I think maybe there was some concept that
the bricks served as some kind of fire wall or barrier rather than being a
typical structural brick wall. I really don't know what the story was with
that, but the space is "mostly" filled with bricks piled on top of each
other and also a LOT of gaps between the bricks.

It's like the old post and beam rubble infil houses of the early 18th
century. Grandad's house had basically a barn frame with gravel and
lime over loose stone and rubble infil, covered in stucco on the
outside and plaster on the inside. Colder than a cave in the winter!!!