Owens Corning sound wall

Ok guys & gals. The Owens Corning Rep/Installer was here tonight and here’s the scoop.

Both my wife and I agree that this product is by far, hands down, easily the absolute best possible wall system that anyone could ever put in their home theater or music room. No ifs, ands, or buts. Especially so if it’s in a basement. It’s as close to mold and mildew proof as you can get, and at the same time allows your cement walls to breath. It’s “no to low maintenance” and is highly resistant to staining from accidental spills of liquids, Crayon marks, etc. Acoustically, your room will be as dead as dead can possibly be. It’s like having wall to wall and floor to ceiling acoustic panels covering every square inch. NRC = 95%. Very very cool stuff to be sure.

The catch ? You need cubic $$$$$$$$$$$$$$$$$$$ to have it installed. It runs about $22 per sq/ft of wall space. OUCH ! Even this rocket scientist was able to figure out that $30k to have one big room paneled (there’s still the floor and ceiling left) is something only high income people can afford. Bummer.

PS: The insulation/backing appears to be a slight derivative of 703. It's a little lighter in color, and slightly more dense. It's about 2 1/2" thick.

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.

I'd advise against doing any kind of waterproofing or sealing drywall/sheetrock, particularly the edges. You won't get a good joint between 2 pieces and it would be difficult to apply to the crumbly edges anyway. I doubt it would look good when it's sanded.

If you're that worried about potential mould and mildew and don't want to use regular drywall or cement board and want to save money, use the green type of water-resistant drywall that's meant for bathroom walls. It handles exactly like drywall but it has that extra coating to resist moisture damage (not submersible, mind you!). It goes without saying you must also have a vapour barrier, whoops I said it.

Another important mould prevention trick if you're using wood studs in the basement is to put a moisture barrier between the concrete floor and walls and the wood. They should not touch because the concrete is porous. You can easily get mould and mildew forming on the wood studs from condensation before it starts to affect the drywall. Think about that.

I had an end roll of roof felt (tar paper) left over from another job that I cut into strips the width of a 2 X 4. I laid this down underneath the studs before screwing down the baseplate and all points where it contacts the concrete basement wall. This should prevent water wicking up into the wood studs. If I was using drywall I would then keep the bottom edge at least a 1/4 inch off the concrete (level at the top of course) to avoid contact with the cold floor. This gap will eventually be hidden by the sub-floor.