John Sayers' Recording Studio Design Forum Archive

Gregwor wrote:

The down side of building the wall in small modules, is that you have a single vertical joint seal between the modules across all three layers which is more likely to fail than overlapped joonts.

Agreed, but with a lot of attention to the sealant, this risk could be minimized. The same precision should be applied to all sealing. Specifically, the ceiling inside out modules share this same risk.

I'm considering ways to mitigate this risk for my design atm. I'm coming up to internal wall framing time in my build. How do you guys plan on/usually go about sealing the ceiling modules to joist joint?

I'm weighing up a tight fit vs a 3-4mm gap all around. With a tight fit I wouldnt get such a good seal as the caulk doesn't go inbetween joist and module, but then again with a single seal, if it fails I have a larger gap for air to pass by, and reduce my spring. With a tight fit I could seal across the point they meet and then maybe put a second thin batten across and seal this too for a double seal.

So many choices...

At Waka: Oh yeah I put those(noggins) in after i took those screen shots lol.

Wouldn't the staggered edges form 3 different vertical seals? one between the frames, one between the first layer of 5/8's and another on the outside layer.

I started doing the math on how much one of these would weigh and I think it would be around 400 pounds( didn't do the math for the 2x4 weigh), the entire wall if one section would be close to 2000 pounds, possibly. Maybe a few chain blocks at different points but even then that's pretty scary. Definitely would rather do it in one piece but I'm really uncertain about trying to raise a 13' x 11' wall that heavy even with a crew of people. I haven't found too much in the way of raising these kinds of walls other the Lilith's thread but her walls weren't as thick I think. She had steel beams to attach the chain blocks to as well.

Can you post a link to your build I'd like to see how you did your walls?

At Greg: I thought about the doing the sole and top plate like you suggest a few hours after I posted

SunkenCity wrote:At Waka: Oh yeah I put those(noggins) in after i took those screen shots lol.

Wouldn't the staggered edges form 3 different vertical seals? one between the frames, one between the first layer of 5/8's and another on the outside layer.

I started doing the math on how much one of these would weigh and I think it would be around 400 pounds( didn't do the math for the 2x4 weigh), the entire wall if one section would be close to 2000 pounds, possibly. Maybe a few chain blocks at different points but even then that's pretty scary. Definitely would rather do it in one piece but I'm really uncertain about trying to raise a 13' x 11' wall that heavy even with a crew of people. I haven't found too much in the way of raising these kinds of walls other the Lilith's thread but her walls weren't as thick I think. She had steel beams to attach the chain blocks to as well.

Can you post a link to your build I'd like to see how you did your walls?

At Greg: I thought about the doing the sole and top plate like you suggest a few hours after I posted

I'm not really sure you would be able to stagger the edges, as it would be extremely difficult to get each layer to butt up tight to the corresponding staggered edge on the next module in practice, have you got a sketchup model showing what you mean? And remember as these are inside out walls you won't be able to seal the sheathing side once they're in place so the most important caulking will be inside the room between the studs.

They would weigh a ton it's true, but as long as your guys are safe you'll be fine. You won't be carrying the full weight though, as you pivot higher the weight gets less.

Me and my brother did my framing in a day and a half just the two of us, but mine wasn't sheathed until after the framing was up, which you can't do with inside out walls (well you can in theory, by fitting modules between the studs like you do with inside out ceilings, but it's not very practical).

My build: http://www.johnlsayers.com/phpBB2/viewt ... 10&t=21269

Those last pictures I posted show the edges of drywall at different lengths staggering the seams by 5/8's from the last layer kinda based off the zig zag approach to the ceiling to wall seams I have seen in other designs.

Is that just using one truck strap Stuart?

On the concrete wall i'm not sure how to attach a truck strap or chain block. The ceiling joists with be exposed but I can't wrap around it with the floor attached.
Probably want a couple points of attachment for safely and so all the weight isn't on one point right

The strap is a reinforced nylon strap, rated at 22,000 lbs breaking strain, 11,000 lbs safe working load. You could hang half a dozen Smart Cars (fully loaded) all together from that one single strap, and it would not even be close to overloaded. The framing would break long before the strap did, but the framing is also reinforced with temporary bracing. But even so, there are also wooden braces under the wall itself that side as the wall is raised, so even if something does give, the wall isn't going to fall.

Work safe. Don't EVER stand under any suspended load that could fall on you. Double-check and triple-check all your weights, loads, capacities, and hardware.

- Stuart -

Is it a ratcheting strap? if so where are you ratcheting it from?

I know at some point the spool on the ratchet would reach its limit of wraps, did you do it in stages of ratcheting, supporting the wall then resetting the strap length?

Thanks Stuart for helping me get my head around this process

also all the wall raising stuff I've looked at they put the sole down then toe nail the frame to keep it in place as the raise it but I don't see that in your photos.

What do you guys think about using one of these or rather 2 maybe to raise a wall?

https://www.harborfreight.com/1500-lb-c ... 96127.html

making progress
If you look you can see the sliver of the rigid foam, that wall is 5/8 drywall, rigid foam, hat channel, 5/8 drywall, studs, no insul, 5/8 drwall. like someone was trying to reduce sound transmission or something.

Ceiling joists

Alright so after really pushing myself to get in gear I've removed all the drywall(including the ceiling what a mess) and taken the room down to the outer shell. Now I'm ready to start beefing up and repairing the outer leaf. I had been putting off buying Greenglue for a while but when two five gallon buckets popped up on local Craigslist I jumped on it. One is brand new sealed the other had maybe a cup or two removed got both for just 125.00. With a lil bit of research I found out that applying greenglue with a trowel wasn't a good idea but saw a post about making pastry chef icing bags out of thick trash bags worked well.

I need to figure out exactly how much green glue is needed per sqft as the pieces of 5/8s that i'm putting inbetween the floor joists will be smaller than a full 4x8 sheet.

Anybody have greenglue application tips other than the bulk caulk dispenser gun? (inb4 buy the gun)

No point in not doing the recommended 2 24Oz tubes per 16sqft ratio, right?

Alright so after really pushing myself to get in gear I've removed all the drywall(including the ceiling what a mess) and taken the room down to the outer shell. Now I'm ready to start beefing up and repairing the outer leaf.

That looks awesome. A nice tall room. Nice and clean!

Anybody have greenglue application tips other than the bulk caulk dispenser gun?

I can't even buy the buckets here so I've only use the tubes. It comes out super easy so you can use any caulking gun with it. It's not difficult and I don't think you need to be super precise with the amount applied. As long as you are in the ball park so to speak, you will be fine.

No point in not doing the recommended 2 24Oz tubes per 16sqft ratio, right?

The stuff is super expensive where I live, so unless you take great care in all other aspects of the build, your efforts and money could be spent elsewhere. Or just do an awesome job everywhere and have a killer studio!

Greg

With a lil bit of research I found out that applying greenglue with a trowel wasn't a good idea but saw a post about making pastry chef icing bags out of thick trash bags worked well.

Just buy the proper applicator. Trying to save a few bucks with make-shift stuff that doesn't even measure the correct amount, doesn't seem like a good way of doing things. You can then sell the applicator again when you are done.

No point in not doing the recommended 2 24Oz tubes per 16sqft ratio, right?

Right! Actually, you can do three tubes per sheet for maximum performance, or two tubes, or even one tube if you are on a very tight budget. I don't recall exactly, but I think one tube per sheet gets you something like 50% of the effect of full coverage, and 2 tubes gets you 75%. But don't take those numbers as Gospel truth... that's just from memory, from years back... Search the GG website to find the actual numbers, or contact their tech support. They might even be able to tell you where to buy the applicator!

- Stuart -

if the ceiling joists are spaced 10 3/8" apart, should I just make the 5/8's drywall pieces an even 10"?

Will that be a proper amount of space for the acoustical caulk to fill?

How should my screws be spaced for a piece of this size? How far apart? Just around the perimeter of the piece or should there be a row down the center of the piece?

I think the ceiling is made of a 2-3 sheets layer of 5/8" plywood from what I can see at couple spots around the building.

info from http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=7264
says the plywood has a surface density of 9.0 kG/m2 so it's pretty close to 5/8" drywall.

So by adding one layer of 5/8"s inbetween the ceiling joists to the 2-3 layers of 5/8 plywood should be about equal to what my other leafs with be with two layers of 5/8"s and one of 1/2 osb, right?

one tube has 70% the effectiveness of two tubes, is what I've been reading.

The applicator wouldn't apply the correct ratio to smaller pieces of drywall.

Adding the pieces to beef up the outer shell every piece is going inbetween the studs a few different sizes I need to be accurate with the Greenglue as its really expensive. If I was using full sheets the tubes or gun would be the easiest way to go.

With the goo bag method you could measure the proper amount into the bag based on the sqft of the piece.

70-90 bucks for a caulking gun is pretty exorbitant.

Nobody else has found a cheaper gun or method? turkey baster?

the developer figured out that a random 3/8" bead was ideal, how hard could that be to do.

Thanks

if the ceiling joists are spaced 10 3/8" apart, should I just make the 5/8's drywall pieces an even 10"?

Will that be a proper amount of space for the acoustical caulk to fill?

Sure. That will give you some wiggle room. For the spots that are too wide, be sure to use backer rod.

How should my screws be spaced for a piece of this size? How far apart? Just around the perimeter of the piece or should there be a row down the center of the piece?

Don't use screws. You need to hold your additional 5/8" drywall up with cleats!

I think the ceiling is made of a 2-3 sheets layer of 5/8" plywood from what I can see at couple spots around the building.

info from viewtopic.php?f=2&t=7264
says the plywood has a surface density of 9.0 kG/m2 so it's pretty close to 5/8" drywall.

So by adding one layer of 5/8"s inbetween the ceiling joists to the 2-3 layers of 5/8 plywood should be about equal to what my other leafs with be with two layers of 5/8"s and one of 1/2 osb, right?

Download my MSM TL Calc Version 2.01 I released yesterday and it will tell you

Gregwor & audiomutt's MSM Transmission Loss Calculator Version 2.01

Poplar plywood is ~9 kg/m^2, so I used that. You can see at the bottom of the screenshot, the TL of your leaves will be very very close to one another! Greg

Do I really need backer rod in a gap that small and only 5/8 deep?

I under stand backer rod is there to fill up the space so you don't use as much caulk, right? but is it more costly instead of just using a bit much caulk?

Cleats? I don't understand, A quick google of drywall cleats didn't bring up much just drywall repair stuff

Nice, I was worried that one layer of 5/8's wouldn't be enough up there.

Is there anything I need to do to the edges of the drywall pieces after I cut them to get the caulk to stick properly?

Thanks