Are we avoiding a triple leaf, or messing up?

Hello All, We just started demolition at our new studio site. The existing walls around us are comprised of 5/8" sheet, Steel studs, pink fluffy insulation, 5/8" sheet (Standard indoor wall construction here). Our intention is to build double frame walls within this room. My question is this: Would it be best to remove the INNER layer of sheetrock and the pink insulation on the existing walls all around the room, re-fill between the studs with rockwool and use this as the FIRST leaf of our double frame? ***OR*** shoud we leave the existing wall as is, then build the first frame of our double frame wall directly on the existing wall, leaving the orginal wall AS IS? Would this be creating a triple leaf system? We can do it either way. In theory, which option is best? Thanks! Adrian

Rip the inner sheets, leave the pink stuff. Add a new frame in front (but not touching) the old wall, fill it with pink and add sheets. You'll end up having a double studd wall, with pink and NO mass within the wall. This will be a Mass-Spring-Mass wall, which is what you want. OR you could hang extra sheets of GB on existing wall. You'll have less isolation (transmission loss) with this "single" wall. But it's cheaper tho..

Thank you, Ro. That is what we were hoping to do (possibility "B", below). What I was curious about was if building the outer frame of our double frame wall ON the sheetrock of the existing wall is a bad idea (possibility "A," below). I THINK this would qualify as a 3 leaf structure and should be avoided. Can you (or anyone) confirm this? Thanks again, Adrian

As mentioned... Rip off the 5/8 sheet on the exterior leaf..beef it up between the studs with the sheetrock you removed (carefully) or new rock, 2 layers would be best for TL. Replace with mineral wool or pink stuff, then your new wall with at least 2 layers rock. Remember you will also be flanking noise through the ceiling and floor so if this room is next to any other areas where you don't want noise to go, you will have to float a floor and definately have a good ceiling design.

Yes, I understand. I guess I'm not being clear (happens a lot! :roll:) I'm specifically asking if we stand to go gain or to lose, isolation-wise, by attempting possibility "A" (pictured above). ie: Is possibility "A" inferior or superior to "B". Thanks!

I believe "B" is better. Adding insulation to the face of an existing two leaf wall, and then building another frame with two layers of drywall, would definitely be three leaf, and the key is that the maximum distance between the leaves is lessened by the middle leaf. But there's not a whole lot to go on here. The only thing we know so far is that your building a studio. We don't know what level of isolation you're going to need, who your neighbors are, or even what floor you're on. I don't have time to identify all the questions we need answered before we can be of the substantial help you need... Please review the sticky threads in this forum for insights into the level of detail we need to have. Thanks, --Keith :mrgreen:

Aloha, Try these :wink: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=7572 http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231 http://www.johnlsayers.com/phpBB2/viewtopic.php?t=2125 Aloha 8)

Hello All, I've read the stickies. It was just a quick question about whether or not one of our options was a three leaf system, so I didn't think I had to include all the details. Thank you, Keith, for the succint answer. Details about the project can be foundHERE. Thanks so much, Adrian

Forget "A", it's tripple leaf indeed. "B" is sure the way to go concerning walls (and even ceiling/floor)

Study this report: IRC-IR-761: Gypsum Board Walls: Transmission Loss Data by the Institute for Research in Construction --Keith :mrgreen: