The No.1 Website for Pro Audio
How would you close this 2nd leaf warehouse build wall to prevent common area noise?
Old 15th February 2020
  #1
Here for the gear
 

How would you close this 2nd leaf warehouse build wall to prevent common area noise?

How would you handle this situation?

I'm trying to open a rehearsal studio in a warehouse. So let's make the following assumptions about the space:

The warehouse I'm building in is a simple box. The floors are thick heavy concrete that I won't be isolating. The warehouse ceiling heights are 14'. I will be building rooms with 10' ceilings. I can have several feet of air gap around all dimensions of the room. True room within a room design with a dual wall assembly.

I will have a common area outside of the rooms that I want to prevent sound from the rooms getting in to.

My question is how do I build the vertical wall on the common area side to prevent sound transmission without coupling it to the warehouse ceiling?

I want to use the warehouse ceiling as the 2nd leaf. I need to block sound from entering the common area from the rooms which means the common area wall needs to extend above the interior room walls towards the ceiling.

I want to decouple as much as possible though to prevent sound transmission to and from outside building. The 4' air gap between interior room and warehouse ceiling is great and I expect coupling the common wall to the warehouse ceiling will be alright. The flanking path it creates would still be several feet long.

See attached image. What would you recommend? Take this into consideration:
1. I am trying to go for value vs quality. How do I get as much performance for the lowest price?
2. This will be a commercial space in an area not likely concerned with sound being at residential levels. Main concerns are sound from rooms getting into common area and sound from outside getting into rooms. (Priority in that order)

I see possible outcomes would be:
1. Couple the common wall to the ceiling. It's not a big deal considering the air gap size and flanking path length.
2. Create a 3 leaf system by building a common ceiling above the rooms and the air gap from this to the warehouse will be large enough that it might still act like a 2 leaf system. Not desired for cost reasons and that it's 3 leaf
3. Build the common wall to something like 13'8" and hang a curtain from ceiling to top of common wall to seal.
4. Any other options?

Additional question:

With such large air gaps would I still want to place a layer of insulation on the warehouse walls that are acting as the 2nd leaf or is it not really necessary when air gaps are so large? I can even have several feet behind the interior rooms that I could see myself using as storage space. See attached image

Thank you.
Attached Thumbnails
How would you close this 2nd leaf warehouse build wall to prevent common area noise?-common-wall-question.jpg  
Old 15th February 2020
  #2
Lives for gear
I dealt with exactly the same issue in my build, except that the 'common area' is instead my wife's hair salon.

What I did was to simply view that dividing wall as part of the outer leaf and build it so it only acts as a single leaf. This way you still get a MAM system between and most importantly the decoupling is there so there are no flanking paths from the recording room(s) to the outer assembly- which then includes that wall.

In my build, there are no issues with isolation to the salon. At most you can *very* faintly hear deep bass from the control room that is closest to the dividing wall when the door is open. When closed you can't hear anything. This can easily be remedied by a door switch controlled relay that turns off the subs when the door is open- although I don't think that will be necessary.

In my build, those are 4 layers of 5/8 drywall for the control room, and 7 layers of 5/8, using scraps to fill all stud bays, for the dividing wall. This was done for two reasons, mass, and isolation to hallway, but more importantly to make the dividing wall only a single leaf.
Old 15th February 2020
  #3
Lives for gear
Oh and reading the text on the picture-

No, if I'm understanding this correctly, unfortunately you will need a decoupled ceiling on the room for the rehearsal space or isolation will be very limited.
Old 15th February 2020
  #4
Here for the gear
 

Quote:
Originally Posted by RyanC View Post
I dealt with exactly the same issue in my build, except that the 'common area' is instead my wife's hair salon.

What I did was to simply view that dividing wall as part of the outer leaf and build it so it only acts as a single leaf. This way you still get a MAM system between and most importantly the decoupling is there so there are no flanking paths from the recording room(s) to the outer assembly- which then includes that wall.

In my build, there are no issues with isolation to the salon. At most you can *very* faintly hear deep bass from the control room that is closest to the dividing wall when the door is open. When closed you can't hear anything. This can easily be remedied by a door switch controlled relay that turns off the subs when the door is open- although I don't think that will be necessary.

In my build, those are 4 layers of 5/8 drywall for the control room, and 7 layers of 5/8, using scraps to fill all stud bays, for the dividing wall. This was done for two reasons, mass, and isolation to hallway, but more importantly to make the dividing wall only a single leaf.
Not sure I'm understanding you correctly.

So you don't have the vertical common wall in your build? You simply had a single wall that you beefed up with effectively 11 layers of drywall for both the walls and frame stud bays. You can see the frame from one of the sides of the wall perhaps?

Thus your room is the studio and the other 'room' is the building itself. The hair salon essentially resides in the air gap between the 1st leaf, which is the studio wall, and the 2nd leaf, which is the exterior of the building. Is that accurate?

It sounds like your concern was isolating the sound to the exterior of the building and didn't care as much to sound bleeding into the salon, which you note as not being a problem considering how many layers of drywall you used to build the 1st leaf.

I don't think I'm understanding you properly though.
Old 15th February 2020
  #5
Lives for gear
 
Kyle P. Gushue's Avatar
The vertical wall should be connected to the warehouse ceiling. The warehouse is itself the 2nd leaf, the rehearsal rooms own independent walls/ceiling is leaf 1.

I would consider going 12ft high in the rehearsal rooms to help maximize cubic footage. Although depending on your HVAC the 4ft might be useful if using 24" ducting.
Old 15th February 2020
  #6
Lives for gear
 
Starlight's Avatar
 

Quote:
Originally Posted by matt2will View Post
Not sure I'm understanding you correctly.
If a picture paints a thousand words then look at posts 32 and 36 in RyanC's New commercial build in Denver topic.
Old 15th February 2020
  #7
Lives for gear
Quote:
Originally Posted by matt2will View Post
Not sure I'm understanding you correctly.

So you don't have the vertical common wall in your build? You simply had a single wall that you beefed up with effectively 11 layers of drywall for both the walls and frame stud bays. You can see the frame from one of the sides of the wall perhaps?

Thus your room is the studio and the other 'room' is the building itself. The hair salon essentially resides in the air gap between the 1st leaf, which is the studio wall, and the 2nd leaf, which is the exterior of the building. Is that accurate?

It sounds like your concern was isolating the sound to the exterior of the building and didn't care as much to sound bleeding into the salon, which you note as not being a problem considering how many layers of drywall you used to build the 1st leaf.

I don't think I'm understanding you properly though.
I do have a vertical common wall in the build, and am (was) very concerned about isolation to the salon. I'm not worried about it anymore, because the isolation is very good.

This common wall wall is built directly under the building's TJIs. It's built as a single leaf with framing under the TJI, and then drywall on one side, the entire stud cavity filled with drywall, and then drywall on the other side. So that is one single leaf, with 7 layers of drywall.

Then the actual studio rooms, which would be analogous to your rehearsal space, are built with their own independent framing, including their own ceiling joists, and 4 layers of drywall. All that drywall is 5/8. In final we used around 900 sheets of drywall and around 100 gallons of green glue.

What type of joists or trusses do you have? I think a pic here would help...
Old 15th February 2020
  #8
Here for the gear
 

Quote:
Originally Posted by RyanC View Post
I do have a vertical common wall in the build, and am (was) very concerned about isolation to the salon. I'm not worried about it anymore, because the isolation is very good.

This common wall wall is built directly under the building's TJIs. It's built as a single leaf with framing under the TJI, and then drywall on one side, the entire stud cavity filled with drywall, and then drywall on the other side. So that is one single leaf, with 7 layers of drywall.

Then the actual studio rooms, which would be analogous to your rehearsal space, are built with their own independent framing, including their own ceiling joists, and 4 layers of drywall. All that drywall is 5/8. In final we used around 900 sheets of drywall and around 100 gallons of green glue.

What type of joists or trusses do you have? I think a pic here would help...
I don't have anything yet, not even a warehouse location. I'm currently doing research and putting together a workbook that goes over the room construction techniques that I'm going to go through with a contractor friend of mine. This will hopefully enable him to give me a better estimate on how much this is going to cost me to build.

So if I'm understanding you correctly, your divider wall is my common wall. You took yours straight to the ceiling. The difference is that you needed both sides of your divider wall to look finished as they're visible on either side. Thus, to act as one leave it had to be nothing by mass and no insulation. Or at least that's how I'm reading it.

My question then would be about what considerations you had when coupling the divider wall to the ceiling. No concern around flanking paths with it?

I'm more concerned about the coupling of the common/divider wall to the ceiling rather than building it as solid drywall. All of my common and rehearsal room walls are only visible from one side and don't need to be a solid mass through the frame.

It sounds like I shouldn't worry about the common wall coupling as the actual rehearsal walls will still be decoupled.
Old 15th February 2020
  #9
Lives for gear
 
Kyle P. Gushue's Avatar
Your rehearsal room is the "inner shell" the warehouse/common wall is the "outer shell". The only time to be concerned about flanking is if the inner shell and outer shell are physically connected. As long as they remain separated flanking isnt an issue.

You do not have to worry about flanking the outer shell to itself. Its by definition connected to itself.

Drywall is located on the interior of the rehearsal room, and interior of the common area. Both wall frames get insulated.

If you don't own build it like the pros by rod gervias its highly reccomended great info and illustrations that show the construction details your contractor needs to do it right.
Old 16th February 2020
  #10
Here for the gear
 

Quote:
Originally Posted by Kyle P. Gushue View Post
Your rehearsal room is the "inner shell" the warehouse/common wall is the "outer shell". The only time to be concerned about flanking is if the inner shell and outer shell are physically connected. As long as they remain separated flanking isnt an issue.

You do not have to worry about flanking the outer shell to itself. Its by definition connected to itself.
That makes sense. The warehouse walls are the 2nd leaf and my new common wall is essentially just adjusting where that 2nd leaf is for this system. It's of not much consequence in relation to the rehearsal room and common area.

The consequence will be when I build rooms on the opposite side of the common area and construct a common wall over there that couples with the ceiling. At that point the two common walls would couple the rooms as part of the same system under the same 2nd leaf.

See attached crude image. Note - this is a side shot. So those common walls are vertical and the top horizontal line is the warehouse ceiling.
Attached Thumbnails
How would you close this 2nd leaf warehouse build wall to prevent common area noise?-coupling.jpg  
Old 16th February 2020
  #11
Lives for gear
 
Starlight's Avatar
 

You want the walls for rooms 1 and 2 to not touch the outer walls at all. See how I have added a gap so they do not touch the bottom wall.
Attached Thumbnails
How would you close this 2nd leaf warehouse build wall to prevent common area noise?-coupling2.jpg  
Old 16th February 2020
  #12
Here for the gear
 

Quote:
Originally Posted by Starlight View Post
You want the walls for rooms 1 and 2 to not touch the outer walls at all. See how I have added a gap so they do not touch the bottom wall.
I'm sorry. I should have specified. That was a side shot I just posted. So the bottom wall you just added is actually making the room levitate in air.

I don't have the budget for that.
Old 16th February 2020
  #13
Lives for gear
 
Starlight's Avatar
 

Sorry, I am so used to seeing plan views that I thought yours was, too.
Old 16th February 2020
  #14
Lives for gear
Quote:
Originally Posted by matt2will View Post
It sounds like I shouldn't worry about the common wall coupling as the actual rehearsal walls will still be decoupled.
Exactly. The only spaces then where sound isolation is compromised is when you are in an area that doesn't have the mass-air-mass assembly from one side to the other.

In my build, this is only the hallway, bathroom and lounge areas of the studio. Today the guys were hanging drywall in the salon and I was doing sessions in the studio. The rotozip and impact drivers especially put a lot of flanking energy into the building's outer shell. On the studio side in those spaces, you can hear it, although actually less than when you're outside. Once you go in a (fully decoupled) room in the studio and close the door, you can't hear any of the tools at all.

To that end you should consider locating all your doors as far away from the common wall as possible, and as far away from each other as possible- when the door to the room is open, it will significantly reduce iso. I have one control room where I will likely use a door actuated relay switch to shut off the subwoofer when it's open.

Your common wall will need to be sealed up airtight against the ceiling, outer walls and floor, and you will need a door that matches the mass per sq ft and has good seals. The individual music rooms will need 4 walls, a decoupled ceiling (could be joists or iso hangers) and a similar door.

Both of the rehearsal rooms will also need isolated HVAC and don't forget about the V, you need ventilation. I can turn mine off and the rooms get very uncomfortable quickly...Once everything is sealed up tight for sound iso, this really becomes a must.
Old 16th February 2020
  #15
Lives for gear
 
Kyle P. Gushue's Avatar
Quote:
Originally Posted by matt2will View Post
That makes sense. The warehouse walls are the 2nd leaf and my new common wall is essentially just adjusting where that 2nd leaf is for this system. It's of not much consequence in relation to the rehearsal room and common area.

The consequence will be when I build rooms on the opposite side of the common area and construct a common wall over there that couples with the ceiling. At that point the two common walls would couple the rooms as part of the same system under the same 2nd leaf.

See attached crude image. Note - this is a side shot. So those common walls are vertical and the top horizontal line is the warehouse ceiling.
Right. You've got the idea. Your pics are proper design.

Technically speaking each wall/mass panel counts as a leaf unless directly connected ie sandwiched on the other. So a wall frame with drywall on either side if it is 2 leafs. A wall with 2 layers of drywall on the SAME side, is just 1 leaf. A two leaf wall system like yours goes MAM. Mass Air Mass. So in your case your assembly (common area and practice rooms) as a whole would be two two leaf systems, ie 4 leafs. Leafs being the mass seperated by air. Depending on on the permiter of the common area is the buildings wall, the buildings walls with sheathing on the interior, or another wall like the ones in front of the rooms, your leaf count for that section would be either 1 or 2.

I point this out not just to confuse you, but to make you aware that the outer building isn't always just the 2nd leaf, in some cases its the 3rd or fourth.

Not trying to be persnikety. That's why i sometimes find it easier to speak of innner and outer shells with regard to room in room, because leafs can add up and things get confusing when the same outer shell can be part of a two leaf system and multiple leaf system at the same time.

The two main design goals for isolation are each rehearsal room gets its own 4 walls and ceiling, which don't touch the outer shell, and that whenever possible you stick with 2 leaf systems, ie one set of walls and ceiling for inner shell, one set for outer.

In cases like corridors for example 3 and 4 leaf systems can be unavoidable, its OK, there are compromises to every design. Its just the goal to mimimize these things, be aware of them ahead of time, and compensate accordingly.

I cannot +1 ryans HVAC considerations enough.

I would also add electrical considerations to be of equal importance.

In the case where your commercial, Fire inspections and code adherence is especially important.

Ive had to install extra fire safety devices (alarm sensors and extinguishers) in commercial studios that did not have sprinklers, which would be a source of flanking via the pipes.

In another case we had to install special locks which the fire dept had keys for in case of emergency. This particular case was a studio in a practice facility in an old mill.

I hope not to confuse you, you seem to have the basic principle down as relates to the main question of the thread.

Ps.

I meant to add that you may find the 4 foot airspace between the rooms to be too much. You maybe be better off using much less airspace, like 1-4", and using the space "gained" for more income generating rooms. Drywall is often the cheapest way to gain isolation, and cubic footage is often the cheapest way to make things acoustically easy to treat.

Considering its a rehearsal space and presumably loud anyway, i would shoot for "decent" isolation, and maximize the number of rooms that generate income. To me 4x drywall layers (or 2x with green glue) on every surface, equates to a good balance between cost, and performance in general for a place like yours.
Old 17th February 2020
  #16
Here for the gear
 

Quote:
Originally Posted by Kyle P. Gushue View Post
Right. You've got the idea. Your pics are proper design.

I cannot +1 ryans HVAC considerations enough.

I would also add electrical considerations to be of equal importance.

In the case where your commercial, Fire inspections and code adherence is especially important.

Ive had to install extra fire safety devices (alarm sensors and extinguishers) in commercial studios that did not have sprinklers, which would be a source of flanking via the pipes.

In another case we had to install special locks which the fire dept had keys for in case of emergency. This particular case was a studio in a practice facility in an old mill.

I hope not to confuse you, you seem to have the basic principle down as relates to the main question of the thread.

Ps.

I meant to add that you may find the 4 foot airspace between the rooms to be too much. You maybe be better off using much less airspace, like 1-4", and using the space "gained" for more income generating rooms. Drywall is often the cheapest way to gain isolation, and cubic footage is often the cheapest way to make things acoustically easy to treat.

Considering its a rehearsal space and presumably loud anyway, i would shoot for "decent" isolation, and maximize the number of rooms that generate income. To me 4x drywall layers (or 2x with green glue) on every surface, equates to a good balance between cost, and performance in general for a place like yours.
Thanks for the advice. I was simply getting hung up on the fact that I will be coupling two rehearsal rooms '2nd leaf' to the same ceiling surface. I wasn't sure if that was something I could avoid or not. As you put it, sometimes it's impossible to avoid and trying to avoid it could actually end up hurting me if I'm adding more leafs.

As far as HVAC, this is where I'll still need some help. As you have noticed this isn't a 'high quality' build and is more focused on value. I haven't determined what is the most cost effective solution. I'm hoping I can use some of the larger gaps I have available to implement something easy and effective.

Electrical - I have some basic guidelines I'll give to the electrician around groundloops, wiring to panel, etc.. See attached image for the type of electrical outlet situation I'd like. I'm fine with the outlet connections being exposed such that I hope it all the power enters through as few wall holes as possible. Durable and dependable is what I am going to recommend here.

Fire safety - I'm plenty happy with installing additional sensors and extinguishers as I expect that is not only easier and cheaper to implement, but also better for the sound isolation as you point out. I will not be placing locks on the rehearsal spaces or even door knobs. Push plates and pull handles only. Simple and all that is needed.

In regards to your p.s., the 4 foot gap is between the rehearsal room ceiling and the warehouse ceiling, not between the rooms. Between the rooms I would like to do a 12" gap. Each wall would be the 2X4 wall (3.5"), and an additional 4" gap (5" gap) of air. This would be filled by 2 layers of insulation 6" thick or 3 layers that are 4" thick. I expect cost savings in using the 6" thick insulation.

I am planning on doing 2 layers of drywall with green glue for 2 reasons. The first is I would like to use light gauge steel framing as it's recommended in Rod's book as having higher sound isolation properties than heavy gauge. So putting as little weight on the frame is desired. The second is that since I'll be contracting the work out I expect the cost to be lower if they don't need to hang as many sheets of drywall.

How does all that sound? Any recommendations or thoughts on HVAC systems and the 12" between rooms?

Thanks for your help.
Attached Thumbnails
How would you close this 2nd leaf warehouse build wall to prevent common area noise?-outlets.png  
Old 17th February 2020
  #17
Lives for gear
 
Kyle P. Gushue's Avatar
Quote:
Originally Posted by matt2will View Post
Thanks for the advice. I was simply getting hung up on the fact that I will be coupling two rehearsal rooms '2nd leaf' to the same ceiling surface. I wasn't sure if that was something I could avoid or not. As you put it, sometimes it's impossible to avoid and trying to avoid it could actually end up hurting me if I'm adding more leafs.

As far as HVAC, this is where I'll still need some help. As you have noticed this isn't a 'high quality' build and is more focused on value. I haven't determined what is the most cost effective solution. I'm hoping I can use some of the larger gaps I have available to implement something easy and effective.

Electrical - I have some basic guidelines I'll give to the electrician around groundloops, wiring to panel, etc.. See attached image for the type of electrical outlet situation I'd like. I'm fine with the outlet connections being exposed such that I hope it all the power enters through as few wall holes as possible. Durable and dependable is what I am going to recommend here.

Fire safety - I'm plenty happy with installing additional sensors and extinguishers as I expect that is not only easier and cheaper to implement, but also better for the sound isolation as you point out. I will not be placing locks on the rehearsal spaces or even door knobs. Push plates and pull handles only. Simple and all that is needed.

In regards to your p.s., the 4 foot gap is between the rehearsal room ceiling and the warehouse ceiling, not between the rooms. Between the rooms I would like to do a 12" gap. Each wall would be the 2X4 wall (3.5"), and an additional 4" gap (5" gap) of air. This would be filled by 2 layers of insulation 6" thick or 3 layers that are 4" thick. I expect cost savings in using the 6" thick insulation.

I am planning on doing 2 layers of drywall with green glue for 2 reasons. The first is I would like to use light gauge steel framing as it's recommended in Rod's book as having higher sound isolation properties than heavy gauge. So putting as little weight on the frame is desired. The second is that since I'll be contracting the work out I expect the cost to be lower if they don't need to hang as many sheets of drywall.

How does all that sound? Any recommendations or thoughts on HVAC systems and the 12" between rooms?

Thanks for your help.
Overall that sounds good, i do have a few comments.

You might want to consider using 2x6 @24" o.c, instead of 2x4. You can decrease the air space between the wall frames to 1-2" so your using the same amount of floor space. 2x6 walls will perform better with regard to isolation vs 2x4.

There is also no need to fill the entire cavity with insulation. Simply insulate the frames from drywall to edge of stud. There is no test data to support that filling the airspace is beneficial, so its not worth spending on. Keep in mind the insulation will likely stick out into the air gap a bit, this is fine. The other consideration is if the insulation is packed too tightly in the air gap, it can bridge the walls causing flanking. In my experience its best to let contractors do what they are used to whenever possible, and in this case its insulating the frame only.

I would verify that light weight steel studs are capable of supporting an in independently framed ceiling of the weight your intending.

Also its worth investigating how much additional load it can support, if for instance you decide to add more drywall after the fact, should you need to.

Also with regard to wood vs steel, its important to note what frequencies the assemblies are better or worse at. With music its good to pick assemblies that are most superior in the low frequencies since this is hardest to isolate, and will be very loud in a practice space with PA systems often having subs, mic'd kick drums and bass amp full stacks. I think rod uses wood studs in his build.

Its also often common in rods builds to use OSB as the first layer of sheathing. This adds structural rigidity to the assembly which is good acoustically in this case.


I attached ir761 which is a bunch of wall assembly tests, and i believe usg also has a construction manual or gypsum construction manual that tests many wall assemblies.

Its worth getting test data from a reliable source for the assemblies your considering to compare the costs and performance.

If you look at the two screenshots you see double wall assemblies. One with 90mm wood studs and a 25mm air gap, the other with 40mm steel and a 65mm air gap. You can see differences in the low end performance. Although not identical stud widths and air space the wood studs perform better under 200hz except at 80hz where they it is .4db less effective.

Either way use 24" spacing for the studs. Its a bit cheaper and performs better. My basic line of thinking would be 2x6 wood walls, with a 1" or 2" airspace.

You may want to consider running cat6 data wires to the room for networking, or other auxiliary uses that might arise in the future.

With regard to HVAC, that's my area of weakest knowledge. Ive never installed or designed a ducted hvac system. Ive either used existing systems or used thru wall or mini split systems.

What might make sense, is the use of a multi split system. This keeps wall penetrations tiny, and let's you/clients remotely control them, so you could turn them off when rooms are not occupied, or at least run them at a more energy efficient temp. Fresh air is still necessary with these in air sealed rooms and a Broan hrv or erv unit would accomplish this.

When it comes to actual designs of the system this is an area where id just call Rod, and hire his services.
Attached Thumbnails
How would you close this 2nd leaf warehouse build wall to prevent common area noise?-screenshot_2020-02-17-15-01-48.jpg   How would you close this 2nd leaf warehouse build wall to prevent common area noise?-screenshot_2020-02-17-14-59-42.jpg  
Attached Files
Old 17th February 2020
  #18
Here for the gear
 

Quote:
Originally Posted by Kyle P. Gushue View Post

You might want to consider using 2x6 @24" o.c, instead of 2x4. You can decrease the air space between the wall frames to 1-2" so your using the same amount of floor space. 2x6 walls will perform better with regard to isolation vs 2x4.


Why would the 2X6 offer better isolation? Not sure I understand why using 2X6 would allow me to decrease the space between the wall frames. In the end the floor space is determined by how far apart the drywall leafs are and not the frame size, right? Even then, wouldn't a 2X4 technically be able to minimize the air gap which is something I don't want to do? I want a 12" minimum gap between walls.

This also sounds like one of those things that if it does provide better isolation, the difference it makes doesn't overcome the increased cost to do so.


Quote:
Originally Posted by Kyle P. Gushue View Post
There is also no need to fill the entire cavity with insulation. Simply insulate the frames from drywall to edge of stud. There is no test data to support that filling the airspace is beneficial, so its not worth spending on. Keep in mind the insulation will likely stick out into the air gap a bit, this is fine. The other consideration is if the insulation is packed too tightly in the air gap, it can bridge the walls causing flanking. In my experience its best to let contractors do what they are used to whenever possible, and in this case its insulating the frame only.
Yea, I was going to recommend to my contractor to use 2 layers of R-rated insulation that's 6" thick and let it spill into the air gap. Do not compress. 12" total between leafs.


Quote:
Originally Posted by Kyle P. Gushue View Post

Its also often common in rods builds to use OSB as the first layer of sheathing. This adds structural rigidity to the assembly which is good acoustically in this case.


Either way use 24" spacing for the studs. Its a bit cheaper and performs better. My basic line of thinking would be 2x6 wood walls, with a 1" or 2" airspace.
Are you saying I would build the walls where it goes frame, layer of OSB, then 2 layers of drywall? Wouldn't the 2 layers of drywall provide enough rigidity here? The OSB might be another item of cost vs benefit where cost trumps again.
Old 17th February 2020
  #19
Lives for gear
 
Kyle P. Gushue's Avatar
Quote:
Originally Posted by matt2will View Post
Why would the 2X6 offer better isolation? Not sure I understand why using 2X6 would allow me to decrease the space between the wall frames. In the end the floor space is determined by how far apart the drywall leafs are and not the frame size, right? Even then, wouldn't a 2X4 technically be able to minimize the air gap which is something I don't want to do? I want a 12" minimum gap between walls.

This also sounds like one of those things that if it does provide better isolation, the difference it makes doesn't overcome the increased cost to do so.




Yea, I was going to recommend to my contractor to use 2 layers of R-rated insulation that's 6" thick and let it spill into the air gap. Do not compress. 12" total between leafs.




Are you saying I would build the walls where it goes frame, layer of OSB, then 2 layers of drywall? Wouldn't the 2 layers of drywall provide enough rigidity here? The OSB might be another item of cost vs benefit where cost trumps again.
This is what i responding to about as far as 2x6.

You:
"Each wall would be the 2X4 wall (3.5"), and an additional 4" gap (5" gap) of air. This would be filled by 2 layers of insulation 6" thick or 3 layers that are 4" thick. I expect cost savings in using the 6" thick insulation."

Instead of 7" of studs filled and a 4" empty space, 2x6's give you 11" of studs and 1" empty space, if 12" total space is the goal.

The 2x6 gives you a deeper insulated cavities, and the thicker studs, which both increase isolation at low frequencies.

Filling the cavity of a 2x4 wall pair equally to a 2x6 requires more labour, increased materials cost, and a higher likelyhood of the workers screwing it up.

Rod reccomends 2x6 over 2x4 here.

Questions for Rod Gervais about his book, Build it Like the Pros

2x4 or 2x6 Wall Construction

wall to slab isolation


Sorry i should correct myself you don't save floor space, just make more efficient use of it in your case. Misunderstood your post i thought you were thinking a 4" + 5" airspace, sorry.

As far as OSB goes, if your intent is 2x mass layers with GG in between, then it is equal cost (roughly) to use OSB as the first layer, instead of a drywall sheet. So frame-osb-GG-type X drywall.

The OSB creates a more rigid assembly, doesn't require the seam taping (less materials/labour) just caulking, is more forgiving if a worker misses a stud when screwing in layer 2, and is much more resistant to impact from musicians bumping things into the wall, errant drumsticks, headbangers, and easier to hang finished treatment, surface mount electrical ect.

You'll find Rod's methods never have costs that trump benefits. They are always the most cost effective way to gain the desired acoustic result. I love the efficiency of his methods, and minimizing of diminishing returns.
Old 17th February 2020
  #20
Here for the gear
 

Quote:
Originally Posted by Kyle P. Gushue View Post
This is what i responding to about as far as 2x6.

You:
"Each wall would be the 2X4 wall (3.5"), and an additional 4" gap (5" gap) of air. This would be filled by 2 layers of insulation 6" thick or 3 layers that are 4" thick. I expect cost savings in using the 6" thick insulation."

Instead of 7" of studs filled and a 4" empty space, 2x6's give you 11" of studs and 1" empty space, if 12" total space is the goal.

The 2x6 gives you a deeper insulated cavities, and the thicker studs, which both increase isolation at low frequencies.

Filling the cavity of a 2x4 wall pair equally to a 2x6 requires more labour, increased materials cost, and a higher likelyhood of the workers screwing it up.
Ahh, that makes sense. 2X6 seems more like the option to go especially, as Rod notes in one of your links, that US regulation dictates a max of 16" OC when using 2X4 in load bearing walls. Since this is a commercial build, might as well go for the beefier stuff anyways.

So 2X6" (5.5" actual depth)wood or heavy gauge framing depending on cost, each filled with one layer of 6" insulation. 1" air gap for a total of 12". If you have any info handy that demonstrates how much additional isolation I gain by adding more to the air gap let me know. I.e. using the same materials but moving to a 14" or 16" wall.



Quote:
Originally Posted by Kyle P. Gushue View Post
As far as OSB goes, if your intent is 2x mass layers with GG in between, then it is equal cost (roughly) to use OSB as the first layer, instead of a drywall sheet. So frame-osb-GG-type X drywall.

The OSB creates a more rigid assembly, doesn't require the seam taping (less materials/labour) just caulking, is more forgiving if a worker misses a stud when screwing in layer 2, and is much more resistant to impact from musicians bumping things into the wall, errant drumsticks, headbangers, and easier to hang finished treatment, surface mount electrical ect.

You'll find Rod's methods never have costs that trump benefits. They are always the most cost effective way to gain the desired acoustic result. I love the efficiency of his methods, and minimizing of diminishing returns.
Not doubting your advice, but then why is the OSB as the first layer not more commonly suggested when using more than one layer in a leaf? Maybe I'm just not noticing it, but everyone seems to just talk about drywall for the most part.

A quick google search puts weight of 5/8" OSB at around 2.06 lb per sq foot and 5/8" drywall at 2.31 lb per sq foot depending on brand. Perhaps this is why it's not the de facto suggestion since it weighs less.

You're saying this slight mass difference is overshadowed by the benefits to rigidness, durability, ease of future work such as electrical, and reduced cost of construction.

Good to know. Adding it to my notes.

Question I have would be, if I were to use a layer of OSB and still use 2 layers of drywall, how thin could I make the OSB layer? In this scenario I want it there more for the side benefits you outlined, rather than adding mass to the system. I'd go thinner on OSB here for cost savings. Is a 1/4" OSB layer too thin?

I expect the thinner sheets wouldn't be so much cheaper than a 5/8" OSB that I would still just go with a thicker OSB layer with single drywall layer.

Just confirm, the OSB doesn't need mud/tape. It only needs caulking in the corners where faces meet. It does not need caulking on the same face where two sheets butt up against one another.
Old 18th February 2020
  #21
Lives for gear
 
Kyle P. Gushue's Avatar
Quote:
Originally Posted by matt2will View Post
Ahh, that makes sense. 2X6 seems more like the option to go especially, as Rod notes in one of your links, that US regulation dictates a max of 16" OC when using 2X4 in load bearing walls. Since this is a commercial build, might as well go for the beefier stuff anyways.

So 2X6" (5.5" actual depth)wood or heavy gauge framing depending on cost, each filled with one layer of 6" insulation. 1" air gap for a total of 12". If you have any info handy that demonstrates how much additional isolation I gain by adding more to the air gap let me know. I.e. using the same materials but moving to a 14" or 16" wall.





Not doubting your advice, but then why is the OSB as the first layer not more commonly suggested when using more than one layer in a leaf? Maybe I'm just not noticing it, but everyone seems to just talk about drywall for the most part.

A quick google search puts weight of 5/8" OSB at around 2.06 lb per sq foot and 5/8" drywall at 2.31 lb per sq foot depending on brand. Perhaps this is why it's not the de facto suggestion since it weighs less.

You're saying this slight mass difference is overshadowed by the benefits to rigidness, durability, ease of future work such as electrical, and reduced cost of construction.

Good to know. Adding it to my notes.

Question I have would be, if I were to use a layer of OSB and still use 2 layers of drywall, how thin could I make the OSB layer? In this scenario I want it there more for the side benefits you outlined, rather than adding mass to the system. I'd go thinner on OSB here for cost savings. Is a 1/4" OSB layer too thin?

I expect the thinner sheets wouldn't be so much cheaper than a 5/8" OSB that I would still just go with a thicker OSB layer with single drywall layer.

Just confirm, the OSB doesn't need mud/tape. It only needs caulking in the corners where faces meet. It does not need caulking on the same face where two sheets butt up against one another.
Rod says here he's never had to use more than a 1" airspace between wall frames.

https://recording.org/threads/soundp...p.57026/page-2

I dont have any data on spacing off hand. I know ive seen a chart before. If i remember correctly there was a rule of thumb where you gain some improvements (notably at Low Freqs) with a wider space and 4" was the point of diminishing returns.

I dont know for sure about rods reasoning, but i would speculate he would use only 1" to maximize the internal volume of the room, and tackle isolation with mass. Again that's just my speculation.

Not sure why OSB isn't suggested more as the base layer. Perhaps people dont all study Rods builds ultra closely (im not sure if he mentions it in his book i was on ed1 for over a decade, just got ed2 recently). I also haven't seen test data on it in any of the common references for wall assemblies, so maybe that's part of it? I never doubt Rod or his methods, because they have never, ever failed me.

Again not knowing Rods reasoning i can only say that he reccomends it, so must feel that the merits of 5/8" drywall outweigh the slight difference in mass. If i understand it correctly the more rigid structure is more effective at Low Frequencies, so there's gains in isolation even with a difference in mass when the assembly is looked at as a whole.

I would go with 5/8" or 3/4" osb unless there was an enormous jump in price from 1/2", which there isn't up here in New England. 5/8" OSB cost about the same as 5/8" drywall, and is barely more than 1/2" osb. Then add GG/drywall as needed.

As i understand it the caulking is only required at the perimeter. I recall max's build thread of dark pines studio where he caulked anyway despite rod saying its unnecessary. I am unsure of the reasoning behind this. Ive not seen him note that the osb has to be tounge and groove. I have seen him state that the first layer of sheeting should be vertical orientation, next layer horizontal, next layer vertical.... Ect.

Since its vertical orientation the seems all land on studs, so perhaps this is the reasoning, i can't claim to know for sure.

The drywall gets taped but doesnt need to be sanded unless its a final layer.

With regard to the finish, you may find it cheaper in the long run to use plasterboard and a rough plaster finish. The plaster dries very hard and its much more resistant to dings and dents than drywall. The rough finish is faster to apply, and easier to fix should dings occur. The plaster adds a slight bit of mass.

I found a guy to do most of a 900sft commercial studio, with 10ft ceilings in 2 days for 1k plus the materials we bought. This was walls and ceilings. For a 200sqft home studio, it cost $500 plus materials we supplied for two guys to tape the seams only, and took 3 days (not full days) because the mud needed to dry in between coats and it required sanding. These were back in the early/mid 2000's. But based on those numbers the plaster was cheaper, faster, and more resilient.

I apologize for not having quotes for rods reasoning for everything, i know data is king. He is one of the masters so even if i dont know his reasoning i still apply his methods, as i said they've never let me down. Hes one of the few people i would follow blind, even tho my curiosity always wants to know the "why"
Attached Thumbnails
How would you close this 2nd leaf warehouse build wall to prevent common area noise?-screenshot_2020-02-17-17-52-16.jpg  

Last edited by Kyle P. Gushue; 18th February 2020 at 01:38 AM..
Old 18th February 2020
  #22
Here for the gear
 

Quote:
Originally Posted by Kyle P. Gushue View Post
Rod says here he's never had to use more than a 1" airspace between wall frames.

https://recording.org/threads/soundp...p.57026/page-2

I dont have any data on spacing off hand. I know ive seen a chart before. If i remember correctly there was a rule of thumb where you gain some improvements (notably at Low Freqs) with a wider space and 4" was the point of diminishing returns.

I dont know for sure about rods reasoning, but i would speculate he would use only 1" to maximize the internal volume of the room, and tackle isolation with mass. Again that's just my speculation.
No worries. If you happen to find anything around the gap distance improving isolation let me know. I could foresee moving from a 1 to 4" gap if the increased isolation is noticeable. This could be easy for me to do in a warehouse setting. I don't want two bands playing at 110 db having their experience degraded because their neighbor is so loud. I know I shouldn't expect perfect isolation, but the air gap could be an easy way to really improve isolation over the cost of mass.

Quote:
Originally Posted by Kyle P. Gushue View Post

Not sure why OSB isn't suggested more as the base layer. Perhaps people dont all study Rods builds ultra closely (im not sure if he mentions it in his book i was on ed1 for over a decade, just got ed2 recently). I also haven't seen test data on it in any of the common references for wall assemblies, so maybe that's part of it? I never doubt Rod or his methods, because they have never, ever failed me.

Again not knowing Rods reasoning i can only say that he reccomends it, so must feel that the merits of 5/8" drywall outweigh the slight difference in mass. If i understand it correctly the more rigid structure is more effective at Low Frequencies, so there's gains in isolation even with a difference in mass when the assembly is looked at as a whole.

I would go with 5/8" osb unless there was an enormous jump in price from 1/2", which there isn't up here in New England. 5/8" OSB cost about the same as 5/8" drywall, and is barely more than 1/2" osb. Then add GG/drywall as needed.
I am going off of Rod's first edition book. I have his second edition arriving tomorrow. If he goes into detail around OSB in that then I am excited to read up on it.


Quote:
Originally Posted by Kyle P. Gushue View Post

As i understand it the caulking is only required at the perimeter. I recall max's build thread of dark pines studio where he caulked anyway despite rod saying its unnecessary. I am unsure of the reasoning behind this. Ive not seen him note that the osb has to be tounge and groove. I have seen him state that the first layer of sheeting should be vertical orientation, next layer horizontal, next layer vertical.... Ect.

Since its vertical orientation the seems all land on studs, so perhaps this is the reasoning, i can't claim to know for sure.

The drywall gets taped but doesnt need to be sanded unless its a final layer.
That is now my understanding too. It is not clear to us newbies what is defined as a seem. I regard it now as any corners with 2 or more surfaces meeting. Two sheets on the same surface is not a seem.

To that though, is it correct to say that layers should have their sheets oriented differently? For example, the first layer should hang sheets vertically and then the 2nd layer horizontally? This would cut down on the direct airflow between where air would flow between sheets and be better at hiding any imperfections in sheets.

Quote:
Originally Posted by Kyle P. Gushue View Post
With regard to the finish, you may find it cheaper in the long run to use plasterboard and a rough plaster finish. The plaster dries very hard and its much more resistant to dings and dents than drywall. The rough finish is faster to apply, and easier to fix should dings occur. The plaster adds a slight bit of mass.

I found a guy to do most of a 900sft commercial studio, with 10ft ceilings in 2 days for 1k plus the materials we bought. This was walls and ceilings. For a 200sqft home studio, it cost $500 plus materials we supplied for two guys to tape the seams only, and took 3 days (not full days) because the mud needed to dry in between coats and it required sanding. These were back in the early/mid 2000's. But based on those numbers the plaster was cheaper, faster, and more resilient.
Thanks for pointing out. I'm not familiar with building materials so correct me if I'm misunderstanding. Walls need to be finished. Painting directly over drywall will look rough and ugly. They need to be taped, mud applied, and then sanded to smooth.

You're suggesting instead of taping and mud I instead apply plaster which, while won't look as smooth, doesn't require taping/mud/sanding sanding and thus reduces build cost. Watching some videos of plaster walls now and it looks like it will look smooth enough for me. I was worried when you used the word 'rough' that it would look and feel like popcorn ceiling. That could help with cost a lot. Thank you.


Quote:
Originally Posted by Kyle P. Gushue View Post
I apologize for not having quotes for rods reasoning for everything, i know data is king. He is one of the masters so even if i dont know his reasoning i still apply his methods, as i said they've never let me down. Hes one of the few people i would follow blind, even tho my curiosity always wants to know the "why"
No worries. I'm not looking to get too into the weeds with data and numbers. If I was trying to build a world class studio then sure, but I'm looking for value and quantity over quality. You're being more than helpful. I really appreciate it. Thank you.
Old 18th February 2020
  #23
Lives for gear
 
Kyle P. Gushue's Avatar
Quote:
Originally Posted by matt2will View Post
No worries. If you happen to find anything around the gap distance improving isolation let me know. I could foresee moving from a 1 to 4" gap if the increased isolation is noticeable. This could be easy for me to do in a warehouse setting. I don't want two bands playing at 110 db having their experience degraded because their neighbor is so loud. I know I shouldn't expect perfect isolation, but the air gap could be an easy way to really improve isolation over the cost of mass.



I am going off of Rod's first edition book. I have his second edition arriving tomorrow. If he goes into detail around OSB in that then I am excited to read up on it.




That is now my understanding too. It is not clear to us newbies what is defined as a seem. I regard it now as any corners with 2 or more surfaces meeting. Two sheets on the same surface is not a seem.

To that though, is it correct to say that layers should have their sheets oriented differently? For example, the first layer should hang sheets vertically and then the 2nd layer horizontally? This would cut down on the direct airflow between where air would flow between sheets and be better at hiding any imperfections in sheets.



Thanks for pointing out. I'm not familiar with building materials so correct me if I'm misunderstanding. Walls need to be finished. Painting directly over drywall will look rough and ugly. They need to be taped, mud applied, and then sanded to smooth.

You're suggesting instead of taping and mud I instead apply plaster which, while won't look as smooth, doesn't require taping/mud/sanding sanding and thus reduces build cost. Watching some videos of plaster walls now and it looks like it will look smooth enough for me. I was worried when you used the word 'rough' that it would look and feel like popcorn ceiling. That could help with cost a lot. Thank you.




No worries. I'm not looking to get too into the weeds with data and numbers. If I was trying to build a world class studio then sure, but I'm looking for value and quantity over quality. You're being more than helpful. I really appreciate it. Thank you.
Your correct about the orientation of the osb/drywall. Vertical for the first layer, horizontal for the next, and keep alternating per layer.

You would probably want to price out 3/4" OSB in case its close in price to 5/8".

By "rough" plaster finish i meant that you can see the trowel marks and lines, as opposed to a smooth finish which may require some sanding and more careful application.

With drywall you have to tape the seams to cover gaps where sheets meet and corners, then sand the seams smooth so you can't tell their there, the wall looks like one uniform sheet. The difference between plaster is you cover the entire wall, where with seam tape you hit just the seams. Drywall can be painted directly, the idea is to hide the seams.

Both plaster and taped seams can be finished smooth. I suggested rough simply because its the fastest and doesnt require sanding. And because its more resistant to dings than drywall. And rough doesnt require much skill to fix if it does get dinged.

All the best!
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump