JimmyD wrote:
Hello All,
I'm in the process of finishing my basement. The ceiling is (will
be) a drop ceiling. The rafters above the drop ceiling don't have any
insulation in them. The basement is where my home theater will be, so
sound insulation is of high importance. My local hardware store
carries Johns Mansville insulation, and I decided to get kraft faced
insulation for ease of installation. I was wondering what thickness
of insulation to buy. The rafters are 9 inches deep (and 15 inches
wide). The two thickness of insulation I was looking at are 8 1/4 and
10 1/4. I didn't know if it was better to go with the 8 1/4 and have
a small gap or go with the 10 1/4 and compress it a bit when I
install it. Here's the brochure for the insulation if that helps:
http://www.jmhomeinsulation.com/pdfs...28c77 7520642
. Also, I live in South Dakota, if that makes any difference.

Thanks.

Jim

If you want sound insulation, I suggest you don't bother trying to make
do with heat insulation.

Check out: http://www.soundproofing.org/

In general you want to block air exchange. Air caries sound very well.
(Try opening your car's window as a train is going by.)

Next you want weight. Heavy things (drywall lead sheets etc.) block
sound well.

You also want to prevent any direct solid connections. Stagger wall
studs or use special isolation devices to keep the sound from traveling
through the wall (remember the two cans on a string (well wire actuarially
worked) you want to break the wire).

Filling in wall cavities with sound absorbing materials (accustical
fiberglass bats) will do a little.

Point source control (special absorption material) at the source of the
sound will also help.

--
Joseph Meehan

Dia 's Muire duit