Help with Planning & Building of my Recording Studio

How thick should my walls be, should I float my floors (and if so, how), why is two leaf mass-air-mass design important, etc.

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Gregwor
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Re: Help with Planning & Building of my Recording Studio

Post by Gregwor »

Ok noted! When you refer to "the place" do you mean either the outer or inner leaf? because I fairly confident that the density of my inner leaf will likely be higher than the outer leaf.
Stuart is referring to the area of your room in general where your resonant frequency is the highest. As an example, say you have four walls and a ceiling and your walls have a 3 foot gap between sheathing. Your ceiling only has a 1 inch gap between sheathing. Assuming your sheathing surface density all around is equal, your ceiling MSM system will have the higher resonant frequency that Stuart is referring to. Since the resonant frequency is directly related to the transmission loss, he's stating that the amount of transmission loss your ceiling is offering is now defining your rooms isolation limit.
When the construction was done, I had no choice to install a vapor barrier so yes the vapor barrier is currently on the warm side of the outer leaf. (inside the house) I know that's the code around here. I don't see how putting it up against the inner leaf will change anything? Do you mean on the warm side of the inner leaf? If that's the case then my HVAC ducts would be exposed to the cold as well no? It would also introduce cold air in between the two leafs no? I'll have to check with local building codes but I'm curious to know how this is done. I'm also wondering how this would work with inside out walls/ceilings...I can't see having two layers of drywall then the stud cavity filled with insulation and then the vapor barrier. I'm sure I'm missing something since having the vapor barrier on the warm side of an inside out inner leaf would defeat the purpose of doing inside out no?
If your walls are built inside out, your vapour barrier is ALMOST in the right spot. If your insulation is pushing out your vapour barrier the same distance as your required "gap", then the vapour barrier will be pressed firmly against your inner leaf sheathing. This is fine. Chances are it's not pushing it out though. If that's the case, rip down the vapour barrier, try to add the correct thickness of insulation to fill your "gap", hold that insulation up with something like string stapled to the outer leaf studs. Then as you build your inside out walls on the floor, install the vapour barrier to it and stand up the wall. The vapour barrier will be directly against the cold side of your inner leaf drywall. That's where it should be.
So really when we talk about "the air gap or space between leafs" that's really the distance from surface to surface correct?
Correct.
So when using and filling out Greg's spreadsheet...the input box for the gap is actually the distance from the stud to stud and not what you're referring to from surface to surface correct?
Correct. And when you choose inside out configuration, the calculator eliminates that leaf's contribution to the gap. Example: If you chose both leafs as inside out, even if you chose 2x6 wood studs, the total gap size would only be the value that you entered into the gap cell.
note that I'm using a 1/2" fiber board vapor barrier and not the conventional 6mm polyethylene.
That's the weird part of the discussion. That needs to be touching the cold side of your inner leaf drywall. Either move it or ditch it and use conventional barrier.

Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
Gregwor
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Re: Help with Planning & Building of my Recording Studio

Post by Gregwor »

Still trying to find some duct liner so I'll be shopping around this week.
The cheapest and best (absorption coefficients) I can find around my area is the Owens Corning QuietR Rotary.

I can get 100 feet of it at Alltherm Services Inc here in Edmonton for:

47” $292.41
48” $298.63

Hope you can find some in Ontario!

Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
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Re: Help with Planning & Building of my Recording Studio

Post by Soundman2020 »

When you refer to "the place" do you mean either the outer or inner leaf? because I fairly confident that the density of my inner leaf will likely be higher than the outer leaf.
Neither! As Greg noted, this is not about your inner-leaf or your outer-leaf, but rather about your MSM SYSTEM! The two leaves do not just act alone: they also act together, as a resonant system, and that's what matters most: the frequency of that resonant system. That's far more important than the resonant frequencies of the individual leaves.

You really do need to do the math here, to make sure that your MSM resonant frequency is low enough that you will get the isolation you need, for the frequency range where you need it.

Don't guess or assume!
yes the vapor barrier is currently on the warm side of the outer leaf. (inside the house) I know that's the code around here.
There is no "warm" side of the outer leaf! The outer leaf is exposed to the weather on the other side, so it is ALWAYS cold in winter. It's the INNER leaf that is warm.

You don't seem to be getting the point here: I'm sure what you have there is correct for your building code FOR A NORMAL HOUSE, but it is not correct for a studio. With a normal house, you would just put drywall on the studs, directly in contact with the vapor barrier, and that would be your inner-leaf. No problem, because the vapor barrier will then be warmed by that inner leaf, since it is direct contact. But when you build a studio, your inner leaf is a long way away from that vapor barrier, and is NOT touching it: it is not going to keep it warm.... That's the problem here.
I don't see how putting it up against the inner leaf will change anything?
The leaf itself will keep it warm, because the barrier is in direct contact with the leaf. If you just leave it hanging in the middle of the cavity, then NOTHING keeps it warm... it will get very cold... and thus the warm moist air that diffuses through your inner-leaf into the cavity, will condense on the nice cold surface of the vapor barrier... that liquid water then creates the perfect conditions for mold to grow... inside your wall, where you won't even know it is there, .... until the damage is already done.
Do you mean on the warm side of the inner leaf?
The inner leaf IS the warm side of the cavity! That's why the vapor barrier needs to be up against it, in contact with it, so it can be kept warm. If it is warm, then the humidity in the air that diffuses through the inner-leaf will NOT condense on it.
If that's the case then my HVAC ducts would be exposed to the cold as well no?
Your HVAC ducts are not vapor barriers!
It would also introduce cold air in between the two leafs no?
I don't understand that: How would the vapor barrier "introduce cold air in between the two leafs"? I don't see how that is possible.
I'm also wondering how this would work with inside out walls/ceilings...
Simple: you apply the vapor barrier in such a way that it will be in contact with the inner-leaf. That's all.
.I can't see having two layers of drywall then the stud cavity filled with insulation and then the vapor barrier.
Neither can I! That would be the WRONG way to do it. The vapor barrier MUST BE I CONTACT with the leaf itself, not separate from it.
I'm sure I'm missing something since having the vapor barrier on the warm side of an inside out inner leaf would defeat the purpose of doing inside out no?
Why? I don't understand that.
Ok right! I wasn't referring so much to the cavity depth but more the fact that my roof cavity is only 90% insulated versus 100% like a wall would be. I think I'll be fine with using an in between figure.
OK, then use a number that is a bit lower than the constant for insulation. The relationship is not linear, though.
So really when we talk about "the air gap or space between leafs" that's really the distance from surface to surface correct?
Correct. If you could shrink yourself down small enough to fit in the cavity, then it is the distance you would see as you look around you: sheathing surface to sheathing surface, across the cavity, regardless of any studs, insulation (or vapor barriers!) that might also be in there.
I'm using a 1/2" fiber board vapor barrier
Do you have a link to that product? fiber board by itself is not a vapor barrier: it would only be a vapor barrier if it had some type of semi-permeable coating on one face.


- Stuart -
Studio45
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Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Thanks for the replies guys!
Stuart is referring to the area of your room in general where your resonant frequency is the highest. As an example, say you have four walls and a ceiling and your walls have a 3 foot gap between sheathing. Your ceiling only has a 1 inch gap between sheathing. Assuming your sheathing surface density all around is equal, your ceiling MSM system will have the higher resonant frequency that Stuart is referring to. Since the resonant frequency is directly related to the transmission loss, he's stating that the amount of transmission loss your ceiling is offering is now defining your rooms isolation limit.
Thanks Greg! This all makes sense now.
Neither! As Greg noted, this is not about your inner-leaf or your outer-leaf, but rather about your MSM SYSTEM! The two leaves do not just act alone: they also act together, as a resonant system, and that's what matters most: the frequency of that resonant system. That's far more important than the resonant frequencies of the individual leaves.

You really do need to do the math here, to make sure that your MSM resonant frequency is low enough that you will get the isolation you need, for the frequency range where you need it.

Don't guess or assume!
Thanks Stuart! I'll make sure to do the math as you said! Once I run the numbers for the ceiling, slopped ceiling/walls, side walls, front and back walls as well as the floor and will post results.
If your walls are built inside out, your vapour barrier is ALMOST in the right spot. If your insulation is pushing out your vapour barrier the same distance as your required "gap", then the vapour barrier will be pressed firmly against your inner leaf sheathing. This is fine. Chances are it's not pushing it out though. If that's the case, rip down the vapour barrier, try to add the correct thickness of insulation to fill your "gap", hold that insulation up with something like string stapled to the outer leaf studs. Then as you build your inside out walls on the floor, install the vapour barrier to it and stand up the wall. The vapour barrier will be directly against the cold side of your inner leaf drywall. That's where it should be.
So if I understood correctly, doing everything right would mean for example that my attic slopped ceilings and inner leaf slopped wall composition would be as followed (Outside to Inside):

-----------------------------------OUTER LEAF ----------------------------|------REQUIRED GAP---------------------|--------------INNER LEAF -------------------------------|
Asphalt Shingle -> 5/8 OSB sheathing -> 2x16" open web scissor roof trust (insulated) -> required gap of MSM system (insulated) -> vapor barrier -> double 5/8" drywall -> 2X4 stud wall (insulated)

Here's a quick picture to show what I think is required. I used a random gap just to show the insulation filling out the gap space but the pics show what I'm understanding in the composition above.
S45-C1.png
S45-C2.png
Now if I remove the vapor barrier (enermax) from the current walls and ceilings of the room and put it up against my inner leaf wall....this would mean that my main hvac trunk and ducts would be exposed to some cold air and I guess now that means that I would need to insulate my ducts with duct liner?

This leaves me with the question and please don't shoot me...but what would be the impact of leaving the vapor barrier where it is now and just add the gap and insulation directly against the vapor barrier and then the inner leaf wall? It just seems like a crap load of work for me to do just to have more insulation before the vapor barrier. I've done some research about double stud wall construction and as pointed out by you guys, there's usually some OSB sheathing that's taped and sealed on the cold side of the inner wall and that basically replaces the vapor barrier. I'm just having a hard time understanding the difference of leaving it on the warm side of the outer wall. I'm also wondering doesn't having the vapor barrier against the inner leaf add another/extra leaf?

Again thanks for you patience and time

Francis,
Studio45
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Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Doh!! I posted too quickly...I wrote my last post before I saw Stuart's response. Sorry about the confusion...here's my response to Stuart's post.
There is no "warm" side of the outer leaf! The outer leaf is exposed to the weather on the other side, so it is ALWAYS cold in winter. It's the INNER leaf that is warm.

You don't seem to be getting the point here: I'm sure what you have there is correct for your building code FOR A NORMAL HOUSE, but it is not correct for a studio. With a normal house, you would just put drywall on the studs, directly in contact with the vapor barrier, and that would be your inner-leaf. No problem, because the vapor barrier will then be warmed by that inner leaf, since it is direct contact. But when you build a studio, your inner leaf is a long way away from that vapor barrier, and is NOT touching it: it is not going to keep it warm.... That's the problem here.
I apologize for not wording it properly. I should have used wall instead of leaf...I keep thinking they're the same but I understand that the leaf is only a surface. I should have said the inside of the outer wall.

If I understand correctly the vapor barrier has to be in contact with the inner leaf (for either single or double wall construction) correct? So if I end up building my slopped ceilings or walls normally (not inside out), then my vapor barrier would need to be on the studs inside the room and the double drywall (inner leaf) would go directly over it right?
The leaf itself will keep it warm, because the barrier is in direct contact with the leaf. If you just leave it hanging in the middle of the cavity, then NOTHING keeps it warm... it will get very cold... and thus the warm moist air that diffuses through your inner-leaf into the cavity, will condense on the nice cold surface of the vapor barrier... that liquid water then creates the perfect conditions for mold to grow... inside your wall, where you won't even know it is there, .... until the damage is already done.
Ah ok! This explains it very well Thanks! I suppose this confirms what I said just above where the vapor barrier has to be in direct contact with the inner leaf to keep it warm.

Im curious though...wouldn't building say an inside out room be harder to heat that inner leaf? I only say this because the inner leaf would be "hidden" under/behind the insulation.

I won't lie...finding out all of this really sucks haha. Just when I thought things were going smoothly... :( Oh well....part of the adventure I guess lol This basically means I need to remove all the enermax panels in that room.
The inner leaf IS the warm side of the cavity! That's why the vapor barrier needs to be up against it, in contact with it, so it can be kept warm. If it is warm, then the humidity in the air that diffuses through the inner-leaf will NOT condense on it.
Got it! 8)
Your HVAC ducts are not vapor barriers!
Ok, so all this has me thinking what this means for my HVAC ducts. The original plan was to run everything in between the inner and outer walls. Does this change anything the fact that the ducts will be behind the vapor barrier? I was planning on having all ducts surrounded in roxull insulation so I suppose the colder area in between the walls wouldn't be that bad if the ducts are insulated on the outside.
How would the vapor barrier "introduce cold air in between the two leafs"? I don't see how that is possible.
Sorry I was thinking about the cold in general and not really air. I know it's not the vapor barrier that cause/introduce cold but more the fact that because the barrier is further away on the inner wall that the area between the two would get colder since the barrier in my case is what seals the room. So taking away the barrier is un-sealing the room but now understand that I'd be re-sealing everything but just further away on the inner leaf.
Simple: you apply the vapor barrier in such a way that it will be in contact with the inner-leaf. That's all.
That sure is simple! lol Got it! The vapor barrier would still need to be directly against the insulation right? no air gaps anywhere?
Quote: I'm sure I'm missing something since having the vapor barrier on the warm side of an inside out inner leaf would defeat the purpose of doing inside out no?

Why? I don't understand that.
Bad explanation from my part. I was thinking that in inside out wall/ceiling the vapor barrier needed to go on the inside of the room therefore I thought the barrier would act as another leaf. Again, I hadn't understood that the barrier would be directly part of the inner leaf.
OK, then use a number that is a bit lower than the constant for insulation. The relationship is not linear, though.
Excellent will do and will post results. I've added new materials (asphalt shingles) and wood structure item/sizes (roof truss) to the spreadsheet and looks to be working but I will do the calculations manually as well just to confirm the math is good. Say Tunned! 8)
Do you have a link to that product? fiber board by itself is not a vapor barrier: it would only be a vapor barrier if it had some type of semi-permeable coating on one face.
Sure thing,

Here is the link to the product https://bpcan.com/produits/enermax-insu ... ier-panel/
and this is the link to the product's installation instruction. https://bpcan.com/wp-content/uploads/20 ... ioneng.pdf

I have a few questions regarding how to properly calculate the density of my outer leaf (referring to Fc=c[(m1+m2)/(m1m2d]^.5)
My outer wall composition of the roof is: Asphalt Shingles (2 layers) -> 1//2" OSB Sheathing -> 18" open roof truss. Question is do I include the Asphalt Shingle as part of the density of my outer leaf? or is the OSB the only material surface I should use?

I'm wondering the same about my outer walls. The composition is 3/4" Pine Board & Batten siding -> 1x3 furring strip -> House Wrap -> 1/2" OSB Sheathing -> 2x6 stud wall. Do I just use the sheathing or the pine siding should be part of it?

Again, I can't thank you both enough for all this help! Wouldn't be able to plan this properly without you guys! I really hope to be able to pay it forward someday!

Cheers,

Francis,
Gregwor
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Re: Help with Planning & Building of my Recording Studio

Post by Gregwor »

I apologize for not wording it properly. I should have used wall instead of leaf...I keep thinking they're the same but I understand that the leaf is only a surface. I should have said the inside of the outer wall.
I think we use the term leaf kind of loosely around here. I personally use the term to refer to the wall assembly as a whole. The way I see it, the "leaf" consists of the framing and the sheathing.
If I understand correctly the vapor barrier has to be in contact with the inner leaf (for either single or double wall construction) correct?
This is weird to word, but I think you get it. Let me try and word it this way: For a wall that is at the perimeter of a home you need the vapour barrier tight up against the cold side of the drywall that is inside of the home. :-| For inside out ceilings, that also applies to your ceiling skeleton lumber.
So if I end up building my slopped ceilings or walls normally (not inside out), then my vapor barrier would need to be on the studs inside the room and the double drywall (inner leaf) would go directly over it right?
Correct.
Im curious though...wouldn't building say an inside out room be harder to heat that inner leaf? I only say this because the inner leaf would be "hidden" under/behind the insulation.
Sure the sheathing won't be as warm as if it were exposed directly to the super warm room, but I think the difference on both sides of the vapour barrier is what makes it work.
I won't lie...finding out all of this really sucks haha. Just when I thought things were going smoothly... :( Oh well....part of the adventure I guess lol This basically means I need to remove all the enermax panels in that room.
There is a reason one of the few smilies on the forum is :horse: Let me put it this way though -- aren't you glad you learned this now before you built your room and had to tear it all down because of mold?!!
Ok, so all this has me thinking what this means for my HVAC ducts. The original plan was to run everything in between the inner and outer walls. Does this change anything the fact that the ducts will be behind the vapor barrier? I was planning on having all ducts surrounded in roxull insulation so I suppose the colder area in between the walls wouldn't be that bad if the ducts are insulated on the outside.
The entire cavity between your outer leaf sheathing an your inner leaf sheathing (where your ducts run) should be filled with insulation. This insulation will keep your duct work insulated from the brutal Ontario cold! That's what matters.
Got it! The vapor barrier would still need to be directly against the insulation right? no air gaps anywhere?
Ideally.
I have a few questions regarding how to properly calculate the density of my outer leaf (referring to Fc=c[(m1+m2)/(m1m2d]^.5)
My outer wall composition of the roof is: Asphalt Shingles (2 layers) -> 1//2" OSB Sheathing -> 18" open roof truss. Question is do I include the Asphalt Shingle as part of the density of my outer leaf? or is the OSB the only material surface I should use?

I'm wondering the same about my outer walls. The composition is 3/4" Pine Board & Batten siding -> 1x3 furring strip -> House Wrap -> 1/2" OSB Sheathing -> 2x6 stud wall. Do I just use the sheathing or the pine siding should be part of it?
Since the shingles and siding have gaps and aren't completely fixed to the sheathing, I personally wouldn't count it in your leaf surface density.
I really hope to be able to pay it forward someday!
Francis, I have learned so much on this forum. Of course as you learn something, it typically opens up more curiosity and then you have more questions. There are some great books out there such as this one that is very well written: http://www.roletech.net/books/HandbookAcoustics.pdf

I'd suggest reading it and others in your spare time and then try to be active on the forum helping people when you can. There are always new users that have questions you can answer. I feel that you are far along on your studio design journey and are more than capable of helping others on here. Having more contributing forum members is a great help for guys like Stuart and I that try to assist people every day!

Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
Studio45
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Location: Ontario, Canada

Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Thanks for the quick response Greg!
Since the shingles and siding have gaps and aren't completely fixed to the sheathing, I personally wouldn't count it in your leaf surface density.
Thanks! I've calculated everything and I guess I'm somewhat happy with the results...sort of.

Assuming that I'm only using the OSB as the density of my walls and roof here are my MSM calculations for each individual composition:

Ceilings (Inside Out): 16Hz
Composition: Shingles (2 layers) -> OSB 5/8" -> 18" roof-truss -> 33" gap -> vapor-barrier -> double 5/8" drywall) -> 2x6 inner wall rafter (insulated)

Side-Ceilings/Wall (Inside Out): 26Hz
Composition: Shingles (2 layers) -> OSB 5/8" -> 18" roof-truss -> 2" gap -> vapor-barrier -> double 5/8" drywall) -> 2x6 inner wall rafter (insulated)

Front/Back Walls Exterior Walls (Normal): 30hz
Composition: OSB 5/8" -> 2x6" stud wall -> 4" gap -> 2x6 stud wall -> vapor-barrier -> double 5/8" drywall)

Interior Walls Between CR and LR (Inside Out in CR only): 22hz
Composition: 2x6" stud wall -> double 5/8" drywall -> vapor-barrier -> 11" gap -> 2x6 stud wall -> vapor-barrier -> double 5/8" drywall)

As you can see @ 30hz the Front and Back Exterior Walls of the room is my limit in terms of isolation. While I was hoping for better numbers I suppose that's good enough since I already know that my floor is the worst of the worst.
Speaking of the floor, it's just a basic non-MSM 2 leaf wooden floor. [1/2" drywall -> 14" open-joist (spray foam insulation) -> 5/8" AdvanTech OSB Sheathing). I wondering I should be doing the same calculations? Can I still use the same formula for this type of floor structure? I've mentioned before that the plan for my floor is to build a damped deck style of floor in both rooms. 1-2" rigid insulation -> 3/4" MDF -> GG -> 3/4" OSB -> 3/4" Hardwood or Laminated
The entire cavity between your outer leaf sheathing an your inner leaf sheathing (where your ducts run) should be filled with insulation. This insulation will keep your duct work insulated from the brutal Ontario cold! That's what matters.
Ok! This is good news! I was getting nervous about having to redo all the HVAC design had I needed to put the ducts inside the rooms. I was planning on filling the cavity with insulation so that's good.
There is a reason one of the few smilies on the forum is :horse: Let me put it this way though -- aren't you glad you learned this now before you built your room and had to tear it all down because of mold?!!
Yeah! No kidding! I have to say though, I did frame my structure box that covers my main HVAC trunk. I can still remove the enermax/vapor barrier on that wall but I'll have leave whatever is behind that box there. I don't see that being a problem since 90% of the wall will still be open. The plan now is to have the vapour barrier over the structural box and behind the drywall of the inside out wall. I'll post some pictures of this tomorrow to show what I mean.
Francis, I have learned so much on this forum. Of course as you learn something, it typically opens up more curiosity and then you have more questions. There are some great books out there such as this one that is very well written: http://www.roletech.net/books/HandbookAcoustics.pdf

I'd suggest reading it and others in your spare time and then try to be active on the forum helping people when you can. There are always new users that have questions you can answer. I feel that you are far along on your studio design journey and are more than capable of helping others on here. Having more contributing forum members is a great help for guys like Stuart and I that try to assist people every day!
Well I'm sure learning a lot on here thanks for you guys! I will for sure do my best to help any newcomers to this site in the future...it's the least I can do! Thanks for sharing the books! I'll def be reading more on the subject, as I will need more knowledge as I progress. Building the studio is one part....I know that treatment is an entirely different monster. I won't lie though, I can't wait to start moving some instruments and gear up there haha. :yahoo:

Cheers!

Francis,
Gregwor
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Re: Help with Planning & Building of my Recording Studio

Post by Gregwor »

Speaking of the floor, it's just a basic non-MSM 2 leaf wooden floor. [1/2" drywall -> 14" open-joist (spray foam insulation) -> 5/8" AdvanTech OSB Sheathing). I wondering I should be doing the same calculations? Can I still use the same formula for this type of floor structure?
No because this isn't a decoupled MSM system.
Building the studio is one part....I know that treatment is an entirely different monster.
The book I gave you the link to goes into treatment too. It's a very cool read!

Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
Studio45
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Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Hey guys,

Can someone help me out with the type of insulation I need to use. I know for the outer walls the insulation required is for the added R value but what should I be using in the empty cavity between the two wall structures and also within the inner wall cavity.

I can only assume that in an Inside Out configuration I would use "R value" insulation (for lack of better term) up until the inner leaf and then use Safe & Sound within the inner wall cavity? What if I'm NOT doing inside out? Should I use normal insulation everywhere?

I've read many different posts where people say Safe & Sound is not much different from the regular Comfort Batt type. Is that true?

Thanks again!

Francis,
Gregwor
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Re: Help with Planning & Building of my Recording Studio

Post by Gregwor »

Can someone help me out with the type of insulation I need to use. I know for the outer walls the insulation required is for the added R value but what should I be using in the empty cavity between the two wall structures and also within the inner wall cavity.
In your MSM cavity, you want an insulation that will dampen the resonant frequency of the cavity. This is usually a nice low frequency. So, you basically want insulation that has favourable absorption coefficients for low frequencies. Since these cavities are usually quite deep and cover a very large area, the price to fill your cavities can get out of control.

I called both Johns Manville and Owens Corning who both told me their products are basically twins of one another. I wanted fibreglass insulation as it's easy to work with and usually cheaper. So I asked them what model of fluffy fibreglass was around 20-25 kg/m^3 and they both said their R24 batts (which are 5 1/5" thick) was the heaviest they made. This is the cheapest way to fill your cavities. Obviously R24 is great thermally as well.

Fibreglass in kg/m^3
High Freq = around 40 (others say 60-80)
Mid Freq = around 35
Low Freq = 20-25

Mineral Wool in kg/m^3
High Freq = around 65 (others say 90-120)
Mid Freq = around 55
Low Freq = around 30 (others say 40-45)

As an example
OC705 is 90 and OC703 is 45
OC EcoTouch R24 or Johns Manville R24 is between 20 and 23 (this is the heaviest pink fluffy they make)

In general
Lighter is better for bass (light fluffy fiberglass insulation)
Heavier is better for higher frequencies (heavy mineral wool)
I can only assume that in an Inside Out configuration I would use "R value" insulation (for lack of better term) up until the inner leaf and then use Safe & Sound within the inner wall cavity? What if I'm NOT doing inside out? Should I use normal insulation everywhere?
Inside of your inner leaf, you should choose your insulation and devices based upon the acoustic response of your room.
I've read many different posts where people say Safe & Sound is not much different from the regular Comfort Batt type. Is that true?
They aren't crazy different for sure, but Safe & Sound does perform well. Check out their website and compare the absorption coefficients.

Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
Studio45
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Joined: Thu Feb 04, 2016 12:47 am
Location: Ontario, Canada

Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Thanks for the info Greg, this is perfect!

Looks like I'll be going with Rockwool R22 or R24 Comfortbatt. I looked at the specs and the density of the comfortbatt product is 32kg/m3 and the Safe & Sounds stuff is 40kg/m3. That's pretty close to my 30hz limit. I have to say I really like the properties of Rockwool insulation versus Fiberglass. I used Rockwool everywhere during out house build and it was a breeze to use. Sure it's going to cost me a little more but in the end I think it'll be worth it.

I still need to post some pictures of the work that's been done so far and that's coming soon. I've been doing a big clean up of the studio since that area had been used as a workshop for the longest time. Lots of stuff has accumulated over time so I'm taking all the stuff I don't need out so I have enough room for bring in some building materials in there and still have the room to work and build. Hope to post something before the weekend.

Cheers and thanks again for the help.

Francis,
Studio45
Posts: 97
Joined: Thu Feb 04, 2016 12:47 am
Location: Ontario, Canada

Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Wow! Over a year since I last posted any progress of my build. I've said it a few times already on this forum but I'll say it again, Time sure does fly!

Well first off, I hope that everyone is doing ok considering this global pandemic situation. I've been well and fortunate to be able to work from home. I've taken advantage of the situation and have spent lots of time on my build. A lot has happened since I last posted and have lots of pictures to share. This post will be the first of many to come as I explain the work and progress since last year.

Here's a quick summary of the things I'd done and worked on to date:
- Built HVAC Silencers for Control Room
- Taken all the furrings and Enermax Panels off for the Control Room.
- Relocated Fire-Alarm and taken all existing A/C outlets and lights out of the Control Room area.
- Opened up the floor above the Garage and strengthened 2 out of 3 required section areas of the floor by adding plywood on each side of the floor joists and solid bridging between affected joists. This was required do to the fact that my inner leaf walls that will be supporting my ceilings are running parallel to my floor joists. Spoke with the structural engineer that designed my house plans.
- Built some custom braces and custom struct system to support the silencer boxes.
- Built a custom winch and pulley system to raise and secure these HUGE boxes to the ceiling

More to come but for now enjoy the progress :). I'll be more than happy to answer any questions about details etc. I will have some questions for Stuart and Greg if they're still around ;). I'm excited to be back at it and hope you're all doing well. :yahoo:

HVAC Silencer Boxes
I'll start with the famous HVAC silencer boxes. I was really excited about building these so I started with the first two needed for my control room. I really wanted to get a sense of how much room I was going to use up for these. :shock: :shock: :shock:

Here are various progress pics of the process of building these HUGE silencers. They sure are HUGE!!

This was the original design
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Overall I'm pretty happy with the way they turned out. I was able to reproduce pretty much what I had drawn in sketchup initially with the exception of a few adjustments I had deal with along the way. I'm taken down some notes for when I build the other two down the road for my Live Room. For now I will be focusing on putting my Control Room together and will leave the Live room for last. Note that in these pictures below I don't show the additional 1/4" MDF that was glued and stapled all around each box. You'll be able to notice that later on in the next coming posts.

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I have plenty of other pictures if anyone is interested. Next post will be about the De-Construction of the room and Part 1 of 3 of strengthening up my floor. Stay Tuned :)
Studio45
Posts: 97
Joined: Thu Feb 04, 2016 12:47 am
Location: Ontario, Canada

Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Deconstruction and Part 1 of 3 of Strengthening Floor Joists
This was lots of fun! :horse: :horse:

After working out the framing details for the studio, I was faced with a situation that required me to do some extensive work on my floor. Basically, the walls that support my ceilings run parallel to the floor joists and are sitting almost right in the middle of two joists. I knew this was going to require that I consult with a structural engineer so I reached out the same person who did the structural engineering work for our house. Good thing he had my plans on his computer and was able to suggest options. He recommended that I glue and screw 3/4" OSB on each side of the 2 floor joists affected by the lightly-loaded wall.

You'll see that I'm basically taking apart the original room by taken off the Enermax panels, HVAC box and insulation around it. It was such a mess up there while I was doing all of this. I'm basically stripping the section where the Control Room will be and where I can start fresh. I can't describe how much it sucked ripping off the sub-floor and taking all the spray foam out of there. I think I ended up filling about 25 large garbage bags for this first section alone. The entire sub-floor was glued with PL premium to the floor joists so once I finished ripping off the sub-floor I had to scrape all the PL glue from the joists to keep things smooth and level. Remember, I have a total of 3 sections like this I need to do. This is only the first section and I've completed the biggest middle section which I will show with pictures in another post. Enjoy!

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That's it for tonight but I will continue and add more later this week.

The next post will show all the work I did to support and raise the first box up against the big support truss at the top of the ceiling. That was also a lot of fun :)

Cheers!
Last edited by Studio45 on Sat Jun 06, 2020 1:52 am, edited 1 time in total.
Stadank0
Senior Member
Posts: 396
Joined: Fri Aug 29, 2014 2:34 am
Location: Zimbabwe

Re: Help with Planning & Building of my Recording Studio

Post by Stadank0 »

Can't see most of your images. Not sure why.I'm logged in.
Studio45
Posts: 97
Joined: Thu Feb 04, 2016 12:47 am
Location: Ontario, Canada

Re: Help with Planning & Building of my Recording Studio

Post by Studio45 »

Hey Frank! Good to hear from you dude! Hope you're going well and that you're enjoying your studio :)

Sorry, I'm not sure why the pics aren't showing up...they are showing up fine for me. I am using img tags with links to my shared google drive so may be related to a permission issue. I'll check permissions and confirm they should be shared.

Could anyone else please confirm if they're seeing the pictures in my last two posts or not? There should be near 25-30 pictures.

I'll be creating a new other posts later today or tonight so I'll read up on why google pics might not be visible to others...

thanks for the heads up Frank!

Cheers!
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