[elawton]

Just a suggestion - as an alternative to the Owens Corning Sound Wall, you could use 4X8 sheets of 1/2" cement board on the interior walls and ceiling. This is a new product that came out in the last year, I think, in these dimensions, which are the same as a regular sheet of drywall. I've seen it at Home Depot for $36/sheet.

Because it's cement, it's a very very hard product, won't dent or scuff. Mind you it's a bugger to put up because you can't drive screws into it as easily as regular drywall or cut holes in it as easily. To drive a screw in, you have to tap the drill quite hard to get it started. You also have to use a diamond blade on the skillsaw to cut that stuff. Makes a ton of dust. I cut it in the garage to contain the dust. You can't cut it with a utility knife. And it's heavy - 75 pounds per sheet. Good workout for the arms! I used 38 sheets!

It's finished just like regular drywall. However, in terms of sound-deadening properties and durability, it can't be beat, except probably by the Corning product at a much higher price.

I used the cement board in my HT and am very happy with the results. I put the green Safe-n'-sound bats between the studs and joists before putting up the cement board for extra sound-proofing. I'm very satisfied with the results. Good isolation from the rest of the house.

One thing I noticed with the cement board is it has tiny bubbles on the surface that are revealled when it's primed. But that can be fixed when it's mudded, or in my case, I'll be applying some acoustic panels to reduce the liveliness caused by the hard surface so the small voids won't be noticeable anyway. Just an aesthetic issue.

To save a few $$ you could use regular drywall for the exterior walls, but of course then you run the risk of mould and mildew. I went the whole hog and applied the cement board on every wall and ceiling. When it's finished, you can't tell by looking at it that it's not drywall.

Now, one other word of caution: I'm not sure how a contractor or tradesman would react to a request to use cement board everywhere. I did mine myself. A contractor would probably charge an arm and a leg to work with this stuff for the reasons mentioned above.