Wall construction problem

  • Thread starter Thread starter mshilarious
  • Start date Start date
mshilarious

mshilarious

Banned
In the process of tearing off drywall to replace with proper soundproof construction, I discovered that on the two interior walls of the room, the drywall has an underlayment of OSB :confused: I am loathe to tear it off, because maybe there is some code here in hurricane-land that requires such reinforcement.

So what is the best approach here? Slap on another layer of drywall and call it a day :confused: The other side of the interior wall can't be easily modified as it is a stairwell.
 
If it were me, I'd leave it up, and put the new drywall over it.

As it is, it gives you a wee bit of insulation value (even though it's an interior wall), it gives you a smooth level surface to attach the new drywall, and it will make the wall more "soundproof" in regards to the room on the other side.
It would also give you a really strong surface if you would ever want to attach heavy and not so heavy stuff to that wall. Stuff like shelves. etc.

Long story short... leave it up.
 
Joeybear said:
If it were me, I'd leave it up, and put the new drywall over it.

As it is, it gives you a wee bit of insulation value (even though it's an interior wall), it gives you a smooth level surface to attach the new drywall, and it will make the wall more "soundproof" in regards to the room on the other side.
It would also give you a really strong surface if you would ever want to attach heavy and not so heavy stuff to that wall. Stuff like shelves. etc.

Long story short... leave it up.
Click to expand...

Yes I'd gotta that far. The issue is the exact nature of the construction to put on top of the existing wall.
 
I've got at least two layers of OSB on every wall in my studio behind the drywall. Leave it there.

We mounted the drywall on resilient channel which was mounted to the OSB.
 
Sorry 'bout that. :rolleyes:
As for what to put over the OSB, I guess that depends on exactly how you're gonna use the room. If it's gonna be a full blown recording studio type set up, I'd wait until more knowledgeable members reply. I'm only a hobbyist, and thus, if I had to make the choice, I'd simply put up new drywall and just leave it at that. But if you're gonna be doing live recording, etc., you have a lot more options/choices, and the more knowledgeable members will be able to help you a lot more than I can.

By the way... while the OSB is exposed, take some pictures of the walls to have a rough record of exactly where the studs are, or mark chalk lines on the floor where the studs meet the sill. This way, if you run into a situation where you want to mount something heavy on the wall, you'll be able to anchor directly to a stud; cuz you'll know exactly where they're at.
It's just a thought.
 
Joeybear said:
By the way... while the OSB is exposed, take some pictures of the walls to have a rough record of exactly where the studs are, or mark chalk lines on the floor where the studs meet the sill. This way, if you run into a situation where you want to mount something heavy on the wall, you'll be able to anchor directly to a stud; cuz you'll know exactly where they're at.
It's just a thought.
Click to expand...

Sorry I wasn't clear--there is already drywall on top of the OSB. Even so, I pretty well know where the studs are, because I can find them from the other side :)

So the wall, right now, is: drywall-OSB-stud-drywall. Insulated in some places, not others :confused: Gotta love builders ;)

I guess the options are:

1) Another layer of drywall
2) RC, then drywall
3) Some sort of membrane, then drywall
4) Other :confused:

I need good isolation but not great. This will not be a large commercial facility, the room is only 17 x 15, it's mainly for mixing/mastering of remotely recorded stuff, and a few of my own unfortunate experiments with music :o

I might record soloists or vocal dubs or something like that, if the room ends up quiet enough. The issue there is the windows on the exterior wall though :( that face a road :( and there are no basements here :(

So mainly with these interior walls, I'm just looking to keep volume in the rest of the house quiet enough that I can work at 85dBSPL whenever I like, notwithstanding sleeping children. Nothing too taxing, I just wanna make sure I don't make anything worse :eek:
 
We mounted the drywall on resilient channel which was mounted to the OSB.
Click to expand...
NO NO NO NO NO!!!! How many times do I have to say it here....Especially YOU Sonic...I TOLD YOU DIRECTLY LESS THAN 2 WEEKS AGO...NEVER RC OVER EXISTING ANYTHING as far as a leaf is concerned. DAMN IT. :mad: I'm too tired right now to explain....AGAIN :rolleyes: for the 44th time here in 3 years! ARRRRRGGGGGGGGGGG !!!


I WISH THIS FUCKING OWNER WOULD GET A GRIP, cause NOW, his refusal to put up some STICKIES, is causing NET FACT to become a norm around here...FUCK. :mad: :mad:
 
MASS. AIR. MASS. Nothing more, nothing less. This isn't "internet fact", it's straight from the man who designed Galaxy Studios - Mr. Eric Desart. How does better than 100 dB isolation between rooms sound? (Answer - it doesn't sound at ALL...)

So whatever you end up with, you do NOT want mass in more than TWO places. Putting RC over existing "Normal" walls and adding more mass will only cost you time and money, and actually make your isolation WORSE. You would be better off just adding that mass DIRECTLY to your existing walls than to make yet another resonant system that will PASS SOUND thru your wall AT THAT RESONANCE.

(reiteration # 7,892 and still going.... :=) Steve
 
That's what I had suspected. So is there anything better than just slapping up another layer of drywall, or is that the way to go?
 
RICK FITZPATRICK said:
NO NO NO NO NO!!!! How many times do I have to say it here....Especially YOU Sonic...I TOLD YOU DIRECTLY LESS THAN 2 WEEKS AGO
Click to expand...

Ok, so maybe I shouldn't have given the advice, but settle down man, we built my walls 6 years ago. I didn't know what a leaf was then, and I'd die before rebuilding everything I've built. And on the walls I'm talking about, they're OK, you don't have to worry about them. Most of them have concrete on the other side with back filled earth.

As for the walls that do have something else on the other side, like my control room wall, it's so thick without glass in it already stops most bass from coming through into the live room. There's a support beam for the floor above that runs between the two walls, and we spaced an inch on each side of that before building the walls. The walls you talk about take up the smallest space possible, but this wall is over 2 feet thick, and most of it is mass. At a certain point, even if you're doing mass air mass air mass, it's going to start working in your favor because of how MUCH mass there is and how MUCH air and space there is. If you don't believe me come over to my house and you can hear for yourself. Plus, there's no way in hell I'd rebuild anything. I've already spent 6 years building and I'm not even DONE!! :D

I do appologize though for giving that advice, but being that most home studios are in the basement with the backfilled concrete on the other side of the wall, it's not the end of the world if you do it slightly wrong.
 
knightfly said:
MASS. AIR. MASS.
Click to expand...

Let me get this straight, because I've been yelled at before for this.

In this picture, it shows concrete, studs, osb, rc, and drywall. this is how most of the walls in my studio are. On the other side of that concrerte is tons and tons of back filled earth. The way I see this wall is, looking from the inside of the studio, mass (drywall), air (created by the RC), mass (the OSB). Then maybe 5 or 6 inches before the concrete.
crosssection.jpg


Please explain how this wall would be incorrect. Not that I'm going to change anything... remember, this was built in the summer of 2000 after I did some research but didn't understand everything enough. There'll be no rebuilding, but I'd just like to understand fully.
 
SonicClang said:
I do appologize though for giving that advice, but being that most home studios are in the basement with the backfilled concrete on the other side of the wall, it's not the end of the world if you do it slightly wrong.
Click to expand...

Mine is not, as I said there are no basements here. That's why I wanted to tear off the drywall and do it right. Well, I can still do the exterior walls and ceiling right :(
 
Still not correct.

Stud ->RC or preferably RSIC and hat channel -> drywall ->drywall. By having the space between the OSB and the drywall in the drawing above, you're still creating the extra leaf.

You want one and only one air space and that's where the studs are - and that should be filled with insulation.

Also, OSB is more expensive and less effective than standard drywall. If you must/want to use a solid wood layer for ease of mounting, use 3/4" MDF. At least it provides the mass you're looking for.

Bryan
 
bpape said:
Also, OSB is more expensive than standard drywall.
Click to expand...

Not if you got it all for free!!!!!!!!! :D That's why we used it!
 
Please explain how this wall would be incorrect.
Click to expand...
Good morning Guys. I'm in a better mood today. :D And I'm really sorry bout the no no no stuff.. But doggone it, I try to scan all the posts here to keep people from wasting time and money. And the owners refusal to listen to my pleas exasperates me!! :(


Sonic, please excuse me. Steve knows much more about this stuff than I do, but basically your wall is this.... MASS-AIR-MASS-AIR-MASS. This is a THREE LEAF SYSTEM. I don;t think me explaining the scientific underpinnings to the principle will offer any more help than this...

partitions2c_663_146.gif


MS, there are a couple of considerations here. But first I'm curious WHY you were removing the existing drywall in the first place. What were your motives? :confused:
As Steve said, it would be BETTER to simply add mass over the existing drywall(which was over OSB already...but now you've REMOVED IT, which in effect means you would be putting it back on again):eek:

But in my mind, there is more to consider than a simple decision. First, exactly HOW MUCH ISOLATION are you trying to achieve. Basically, this detemines the choice of methodology of iso system construction, although existing conditions has a bearing too. The thing to understand is assembly RATINGS. Here is what I mean.

If you WERE trying to achieve, say a 65db isolation, I doubt if a SINGLE layer of drywall ADDED to the existing leaf would meet your goal. Personally, just looking at the illustration will show you why. The system on the far right has an STC(which doesn't relate to music at all) of 63, and thats assuming all other flanking paths and assemblies meet the same criteria. Such as doors, HVAC, windows floor etc. The REAL problem is LOW FREQUENCY TRANSMISSION...and where you are trying to keep the transmission from OCCURING. Let me put it this way.

IF, you were trying to keep drums from bothering a neighbor 25 feet from an exterior wall, and your EXISTING FLOOR was a WOOD FRAMED assembly, personally, I believe you could add 5 layers of drywall to the existing walls and cieling, and you MAY STILL be able to hear it outside simply because the floor
becomes a flanking path for structural transmission to the exterior walls, as the walls are(usually) framed on top of the floor, which itself is supported by a foundation. This is the trouble with trying to give advice on this stuff WITHOUT knowing the WHOLE BALL OF WAX! :confused: ;) This is the WEAK LINK syndrome.
EVEN if you were able to use RC correctly, it may STILL not meet your goal as you can only fasten a maximum of TWO layers to it. And this includes the CIELING, which is ANOTHER little dilema. The existing ceiling and roof make up another TWO LEAF system, which may or may not be a problem. However, you still have to look at the WHOLE THING, including the floor, if high SPL isolation is what you are after. Even then, exactly WHAT are you trying to isolate from WHAT? :confused:

I can tell you this though. There IS a way to deal with the OSB IF you still want to use RC, assuming this type assembly/MASS will meet your goal. The way to address this problem of three leafs, is simply ELIMINATE the OSB from the leaf equasion by CUTTING HOLES in the OSB at EVERY STUD CAVITY. Either by a drill, hole saw, or skill saw/reciprocating saw...whatever. You MUST VENT this leaf. Only then, will the OSB disappear from the equasion. Once this is done, RC can be fastened OVER the OSB. However, one little tidbit of information. BECAUSE of the principle of how RC works, IF the flange that NORMALLY fastens to the stud, now is fastened to the OSB, in effect, you LIMIT its ability to DECOUPLE from the OSB, as the entire length of the fastening flange rests directly against a plane, instead of being free to vibrate, which is HOW it decouples. Therefore, NOW you need to nail some furring strips OVER the OSB, inline with the existing studs. This gives you the
the same thing as the edge of a stud to fasten the RC to. This also should preserve any SHEAR WALL requirement which is PROBABLY why the OSB is there in the first place. :eek: Yet, like I said, this senario may NOT meet your goal though. Thats why you need to tell us everything you can MS.

BTW, my disclaimer is in FULL EFFECT here, as usual. Remember, I'm only trying to be a good member. :D
 
Why did I sense an overly bloviated response from Rick was coming? :D
 
One other thing here in regards to RC. Once you decide to do this, REMEMBER, now, your door jambs etc must be extended and FLOAT free of the drywall. :eek: If you need it, I'll post some details how to deal with these little conundrums that no one mentions. They could totally negate the rc if not done correctly. SAME WITH FASTENING THE DRYWALL TO THE RC!! It HAS TO BE DONE RIGHT...ie NO structural connection via screws tharough the drywall touching the OSB!! :(
 
Sonic, YOU could improve your walls performance by doing what I said. CUT holes through your DRYWALL/OSB, and PATCH the holes in the drywall. I can't tell you the estimated improvement specs, but it MIGHT put it over the edge if you NEEDED IT. Just a suggestion.
 
, I'm just looking to keep volume in the rest of the house quiet enough that I can work at 85dBSPL whenever I like, notwithstanding sleeping children. Nothing too taxing,
Click to expand...
Nothing TOO taxing? 85 SPL? :eek: :eek: :eek: Hmmmmmmmm :D Well, I think we need to talk... ;)
 
You must log in or register to reply here.
Back
Top