Basement recording studio in Columbus Ohio Build Diary

[Esco]

I just found out through private messaging with Glenn that I build the walls incorrectly. I nailed the the walls to the joists above using neoprene as the barrier between the two walls. After searching a similar construction diary I see a post from john Sayers that states "This is the correct way to build a wall" (see below)

building walls.jpg

So now I have to tear all of the walls down and take about 2 inches off then put them back up right?

So what is the neoprene for if the walls don't connect to the joists? Does the neoprene go on top of the walls?
Glenn you said a tight fit. So how close should the neoprene be from the joists above? Touching... almost touching?? I want to do this right.

[RJHollins]

Hi Esco,

I checked out your build video ...

Something that caught my attention ... it had looked like you had a stud frame wall
built against the concrete wall [red ??]. Couldn't tell if you had an 'air gap' there.
I know 'my' instructions were to build an inch or two away from the foundation wall.

It was hard to tell from the vid ... but just mentioned it for clarification.

Sorry to hear of the 're-build' ... glad it was spotted before it was too late !

[Esco]

Your right! It's my fault though. I had a contractor friend come over and he recommended that I build it that way. The issue is that I have never build a wall before so I just took his word for it and now I'm paying the price. So yeah, back to square 1

I will try to tear the walls down and fix then asap. I'm still trying to figure out what "neoprene and lag screws with neoprene tubing and washers" for the walls means! lol

[xSpace]

I just found out through private messaging with Glenn that I build the walls incorrectly. I nailed the the walls to the joists above using neoprene as the barrier between the two walls. After searching a similar construction diary I see a post from john Sayers that states "This is the correct way to build a wall" (see below)

building walls.jpg

So now I have to tear all of the walls down and take about 2 inches off then put them back up right?

So what is the neoprene for if the walls don't connect to the joists? Does the neoprene go on top of the walls?
Glenn you said a tight fit. So how close should the neoprene be from the joists above? Touching... almost touching?? I want to do this right.

The picture you show is one of >several< ways to correctly build a framed assembly. ISO clips/track applied to the joists above with the sheetrock attached to the ceiling going to the interior side of the new framed walls.

But if you have a true decoupled, e.g. framed walls and joists on the the top of these walls, you still have a correctly framed assembly, with a better transmission loss.

As to neoprene, if you use it at all, it would be on the rat sill (sometimes call a sole plate or bottom plat) to seal an uneven floor. I have glued plates and caulked plates, which ever I had handy, in the event of an uneven floor. But sealing up the bottom plate is still a good idea, but neoprene isn't something I would even waste my time trying to purchase since caulking is a better overall seal.

[Esco]

Thanks for the help xspace. I have seen your posts on the forums and you seem to know what your talking about. So nailing the walls to the joists is the wrong way to do it right?

[xSpace]

It creates a direct flanking path which will allow vibration/sound a direct path into and out of the environment.

The second issue is that the deflection of the existing upper floor system will become rigid, your floor upstairs will loose the flex it currently has and the potential for upward thrust (from the basement floor thru the framing to the upper joists) can create a problem with the stability of the structure( in the event of upward thrust)

I suggest to people to install 1/2" or 5/8 inch OSB plywood to the interior of the newly framed room(s) to allow the frames to stand by themselves.

It is always assumed that a joist ceiling will be placed on top of the newly framed walls when this is recommended since the walls can stay erect with the OSB sheathing but the length of the wall runs require framing joist members at standard layout per the room width, nailed directly to the top of the wall to ensure that the wall framing isn't or rather doesn't have ability to be pushed in or out of alignment an subsequently create something that could collapse.

[Esco]

Ok I see what your saying. Thanks for the help. I'm pretty new to the whole thing.

[Esco]

I have a question for everyone. I built the walls then at the top of the walls I applied a layer of neoprene as a sound barrier between the joists and wall. I then nailed this into the joists.....

Why does this not work. Wont the neoprene act as a sound barrier?

[xSpace]

two things...the nails create a flanking path(already said that).

The scope of your job is to create a decoupled environment.

Second is that the neoprene is not a sound barrier but a filler. A filler for a void, an empty space, nothing more and nothing less.

Vibration will take the path of least resistance, given that path, vibration can channel a 12D nail into a low frequency issue.

[Esco]

Xspace. Sorry for making your repeat yourself. I see what you mean. However Glenn has me using rubber bolts to connect to the joists. Wont the vibration still occur with bolts? I guess I'm very confused. To me it seems as if I should not have the walls connecting to the joists at all.

I am not questioning Glenn's knowledge because I know hes spot on with his designs. I am just trying to understand the theory behind using rubber bolts to connect to the joists.

[xSpace]

You will have to ask Glenn what he has in mind but any direct connection will be a negative.



Just because there is a supposed break via a neoprene slip, the direct hard connection you make with the fastener will couple the two assembles together.


Rubber bolts:? Do not exist!!!

[Esco]

I will be working on using rubber bolts to decouple the walls tomorrow night. Per Glenn

1/4" bolts, 3 1/2" long, 1" diameter washers, wrap 1/8" around the bolt so a 1/2" hole. the bolt allows you to selectively tighten until you get the balance between hard contact/stability and decoupled. space them about every other joist or 32"

And here's more detail on how it will work from Glenn

the bolt is metal, there is a rubber washer under the metal one and a tube around the bolt long enough to keep it from contacting the runner. the neoprene should be just snug enough not to move and loose enough not to form a connection to the upper joists.

Makes sence to me once I thought about it. I will post pictures to make sure I am doing things correctly.

I will also be moving the walls out a inch from the concrete walls. Hopefully this will get me back on track.

[rod gervais]

the bolt is metal, there is a rubber washer under the metal one and a tube around the bolt long enough to keep it from contacting the runner. the neoprene should be just snug enough not to move and loose enough not to form a connection to the upper joists.

I can see how this would work, however there is a certain challenge that exists doing this...

In any case where there is a rubber member that cushions an (otherwise) hard connection, the compression of the cushion is critical to assure isolation......

If the rubber is compressed either too much or too little - the isolator becomes a transmitter......

It is for this reason that items like the WIC isolators sold by Mason Industries are manufactured "pre-loaded" - with exactly the right amount of compression to assure their center frequency is 10Hz.

I would seriously suggest that you consider purchasing a mechanics stethoscope in oder to make certain that there is no transmission between the various assemblies.........

Install everything loose fit - then begin to draw everything into place - in much the same manner as you would as drum head - while checking with the stethoscope to determine exactly when you have reached your goal.

In order to determine that you can have someone tap on the existing structure with a 2lb hammer while you "listen" through the stethoscope to make certain the taps are not being transmitted into the isolated room's structure.

Rod Gervais
GIK Acoustics
Director of Education
http://www.gikacoustics.com (USA)
http://www.gikacoustics.co.uk (Europe)
Tel.(US)1.888.986.2789
Tel.(UK)+44(0)20.7558.8976

[Esco]

Hey Rod,

Thanks a ton on the reply!
Where would I get a mechanics stethoscope? It makes perfect sence what you are stating and I would hate to just tighten the bolts until it "Feels right" LOL.

I want to build this recording studio the correct way so any advice is welcomed and I can assure you that I will take the time to read the comments and document the progression of things as I learn.
I have your book, Glenn referred it to me. Amazing stuff. I'm very much a newb so it's sort of difficult to wrap my head around things but this community and yuor book helps to get me on track. Thanks again!

[rod gervais]

Esco,

You can pick one of those up at any auto parts store - they are not expensive. I own a couple of them - use them all the time when doing framing inspections on (local) studios I design........

Rod Gervais
GIK Acoustics
Director of Education
http://www.gikacoustics.com (USA)
http://www.gikacoustics.co.uk (Europe)
Tel.(US)1.888.986.2789
Tel.(UK)+44(0)20.7558.8976