Well, the day I was waiting for finally arrived....deconstruction. Just in case you are new to this thread, I previously added a layer of 1/2" OSB and 1/2" drywall with Green Glue to the existing house framing back when I was going to build a high-value theater. Enter scope creep and...well...here I am.
The primary reason I am removing the decoupled framing is to remove these two layers of sheet material from the original framing and avoid the Triple Leaf Effect which can dramatically reduce soundproofing effectiveness and potentially introduce resonances. Quite literally, there is a 10 STC improvement by going with a double leaf wall vs. triple leaf. The Green Glue Company has an excellent white paper explaining this effect HERE
. With the LFE firepower I have going into the room, I wanted to do the best job I could with sound containment.
The other reason is to recapture about 5-6 inches of usable room width I left behind because I didn't want to trim down all the closed cell spray foam on the right wall. The rookie installer mistakenly sprayed 6-7 inches of foam depth vs. the 2" I paid for. Cutting down the foam and recapturing this room width will allow me to use 4" deep acoustic treatments vs. 2" without any loss of finished room width.
I was fortunate to have
help me with today's deconstruction. This was a two-person job almost every step of the way, without question, and I GREATLY appreciated his skilled help. He'll be back tomorrow for day 2. Now on to the pictures.....
Today we focused ONLY on the rear wall. This is how the back wall looked this morning with the drywall/GG/OSB sheet material behind the decoupled wall.
I had used a bit of Liquid Nails under the bottom plate and was very concerned that cutting through this adhesive was going to be difficult and take forever. With Kevin on the Sawzall, I was using a series of pry bars to lift the bottom plate as much as possible to make the cutting easier. To our surprise, I was able to pop the bottom plate off the subfloor using only prybars. Loosening the entire wall only took about 15 minutes. What a relief!!
Since I used screws, the wall disassembled fairly quickly.
With me working the prybars and Kevin working the Sawzall, we were able to cut through all the screws that were holding the OSB to the back side of the framing. It was slow going, but we kept at it.
We ended up removing the entire stud at the vertical OSB seams.
I bought a thin-kerf Sawzall blade and was able to run it right down the seam, with the factory edges of the OSB as a guide. You can see the light poking through.
Here you can see the same cut (with flash) and you'll notice I removed all the screws holding the drywall to the OSB. The Green Glue has permanently bonded the two layers and I will be going through both layers with a single 2" drywall screw when reinstalled on the back side of the rear theater wall.
First perfect 4'x8' piece removed!!
Here you can see just how cleanly we were able to remove the pieces in-tact for reuse.
Here's a close-up look at the carnage after removing all of the sheet material from the rear wall. You can see I ended up with four full 4x8 sheets plus a small extra piece. Each 4x8 is HEAVY!
Another view of the rear wall
We reinstalled the studding we removed and shifted all four pieces onto the backside of the wall, ready for re-installation.
There wasn't enough room to get these 1" thick sheet sandwich pieces behind the HVAC unit, so we has to improvise with removing the surrounding framing, cutting a path through blocking and working together to move the entire HVAC unit about 2 inches, pictured below. It took a little work, but we were able to get the needed room to install the sheet material. I'll have to figure out something fancy to get everything reattached properly, including all the studding we had to remove.
Studding around the HVAC needs to be reinstalled...I'll probably get to that tonight or tomorrow morning.
Tomorrow's goal is to remove ALL the remaining framing, plus the sheet material along the left wall. I think it's doable now that we've worked out the process. From there I will be cutting down the foam to the proper height, re-framing, adding decoupling brackets to the wall framing, insulating and then skinning the room. Today was the spark I needed and I look forward to keeping up the pace and have a finished shell over the next few weeks.