2nd floor studio, floor insulation?

[iiaannnnaaii]

Hello,

This is my first post on this wonderful site... after wading thru endless rabbit holes of poor information and product pitches I have finally found the right place. Thank you very much!

I will now apologize in advance for not posting a picture or diagram; I am still in the research process and while I have the space I plan to build in designated, the dimensions are flexible and I think a picture of an old barn isn't really going to add much erudition at this point.

General overview of my project:

space=

2nd floor of an old New England barn.

Use/volume=

I play drums and we like to play at a pretty high volume, not spinal tap 11 by any means but i like to play the drums full tilt and hear everyone else. There are houses close to us, but our neighbors are very cool.

materials=

My plan (so far) is to build a room within a room; staggered framing, rock wool insulation, walls to be hung with 5/8" sheetrock on on side and 1/2" sheetrock on the other side, vents for intake and outtake to feed into the unused portion of the barn with baffles. I plan to caulk the hell out of every nook and cranny,s I like what I have seen written about building floor to ceiling bass traps in the corners of the room, window, I have one, not sure if I will close it off or look to double it up, the door will be the densest wood I can find and I will make sure it's airtight.

I have chosen to forgo green glue double layered sheet rock for economic reasons and after reading "Sound Studio Construction On A Budget" by Everest in which he suggests it's ok to do without. My questions, which will come later, are about floors and ceilings.

I'm open to any suggestions, of course.

Floor questions=

I have "Home Recording Studio" by Gervais and while he goes into great detail about floors (as do many other sources and much more dubiously), as far as I can see, he only offers one idea for a 2nd floor studio that can not support the weight of concrete; which is in chapter 10 and is a DECOUPLING FLOOR SYTEM; which looks great but I wonder if any of you could help enlighten me further on a few points.

(Before I get to the questions; if the barn were mine alone I would be out there right now supporting the floor in order for it to bear a load of sand or concrete, however, my girlfriend (a city girl) is in love with the aesthetics of the old barn as it is and if I were to start lagging LVL's to the existing joists or running posts down the center to the first floor I might as well build a bedroom out there for myself. Compromises must be made in these delicate matters and I think I'll make do with the existing circumstance.)

ok, to the questions=

1) In Gervais's schematics the bottom most layer of the floor is labeled "concrete deck planking", my floor is 2 x 6 barn board; will this do?

I have looked into concrete planks and while they seem expensive I would be willing to bite the bullet and put them in if needed but I haven't been able to locate a NRC on them and not sure how much difference they would make or if my 2 x 6 wood is ok by itself.

2) also in Gervais's schematics, the 2nd most bottom layer of the floor is 2" pdf rigid fiber glass, I've priced that out and I'm ready to go on it. Question... will it alone support the plywood layers above it or should I frame a floor system? He does not show any framing in his drawing so I assume that the fiberglass will be fine alone but I don't want to make a misstep.

3) Does any one have any other wisdom to offer when it comes to 2nd floor sound absorption?
I live in a quiet area so sound coming in is not so much a concern; it's keeping the neighbors happy that I worry about most, but again my neighbors are pretty cool and a little bleed would be fine.


thank you so much if you have taken the time to read this and again, this forum is a godsend,

Ian

[iiaannnnaaii]

I forgot to mention that I will be using the studio as a rehearsal space as well as doing amateur recording projects. As I build up the arsenal of recording gear ( right now it will be directly to my laptop) I will move to doing more recording and I'd really like to get into mastering.

I know I mentioned before that my dimensions are flexible; I've read about the ideal ratios for sound waves inside a room and I'm sure that I can make that happen with the space available, I guess my first concern is getting a better idea about how to construct the floor, figure out material costs and then I will start playing with the layout.

I have all the framing material I need and some of the sheet rock already in store.

Again, any help will be greatly appreciated.

[iiaannnnaaii]

As my research continues I feel the need to rephrase and ask more questions... I have experience in construction but none in sound isolation so please bear with me...

first off, staggered wall is out, I've decided to move to doing a two leaf double wall.

Concrete planks seem pointless to me, I think I got hung up on an unimportant detail.

Rockwool (Roxul here in the US is the ubiquitous brand) is said to have much better absorption of sound than regular fiber glass insulation, is it true and worth the expense?

Do different thicknesses of gypsum board on either side of a wall really absorb different frequencies or is it better to just go thick on both sides? I've read both.

Floating walls= This I understand but I'm wondering if there is an effective alternative to using the Mason Industries ND isolators that I could fabricate and/or implement myself; I've seen chit chat about neoprene this and neoprene that in varying applications (strips, pucks, what have you) but I really don't know enough about the physics to decide what is a sound idea (forgive the very, very awful pun) and what is not.

I hope I'm not annoying you guys, just looking for a little direction.

[Soundman2020]

Hi there Ian, and welcome to the forum!

after wading thru endless rabbit holes of poor information and product pitches I have finally found the right place.

I have no choice but to agree with you there!

2nd floor of an old New England barn.

Do you have alternatives? 2nd floor studios are harder to isolate than ground floor...

walls to be hung with 5/8" sheetrock on on side and 1/2" sheetrock on the other side

Stick to 5/8 on both sides. Half-inch drywall is too flexible, too low in mass, and has other undesirable characteristics. Pay the extra few bucks, and get 5/8 only.

I have "Home Recording Studio" by Gervais and while he goes into great detail about floors (as do many other sources and much more dubiously), as far as I can see, he only offers one idea for a 2nd floor studio that can not support the weight of concrete; which is in chapter 10 and is a DECOUPLING FLOOR SYTEM;

Right. Rod gives only one option, because there just aren't many more for second-floor builds!

1) In Gervais's schematics the bottom most layer of the floor is labeled "concrete deck planking", my floor is 2 x 6 barn board; will this do?

I have looked into concrete planks and while they seem expensive I would be willing to bite the bullet and put them in if needed but I haven't been able to locate a NRC on them and not sure how much difference they would make or if my 2 x 6 wood is ok by itself.

I think you are asking the wrong questions first! The very first question you should be looking at, is how much isolation you need, in terms of decibels. Then based on that, you should be looking at materials and techniques that will get you the right amount of isolation. And based on THAT, yo should be asking your structural engineer what you need to do to beef up your floor structure enough to handle that amount of mass.

2) also in Gervais's schematics, the 2nd most bottom layer of the floor is 2" pdf rigid fiber glass, I've priced that out and I'm ready to go on it. Question... will it alone support the plywood layers above it or should I frame a floor system? He does not show any framing in his drawing so I assume that the fiberglass will be fine alone but I don't want to make a misstep.

If you were to frame it, you would lose the entire benefit that Rod is trying to give you! The fiberglass compresses slightly under the load of your floor, and acts as a resilient layer between your floor and the sub-floor. If you put framing in there, then the framing takes the weight, instead of the fiberglass, so you have no resilient layer, and instead you have a major and very direct flanking path from your floor to the sub-floor.

3) Does any one have any other wisdom to offer when it comes to 2nd floor sound absorption?

My most useful piece of wisdom on 2nd floor builds is this: If you possibly can, move it to the ground floor... If there is no chance at all you can do that, then be prepared to spend some big money on doing it right, if you need high isolation.

I live in a quiet area so sound coming in is not so much a concern; it's keeping the neighbors happy that I worry about most, but again my neighbors are pretty cool and a little bleed would be fine.

It's not your neighbors that you have to keep happy: it is the cops. Your current neighbors might not care at all, but who knows when one of them might leave, and a new not-so-tolerant guy moves in, and reports your noise violations every night...

Check your local legal requirements on how quiet you have to be, and build the studio to achieve that amount of isolation.

first off, staggered wall is out, I've decided to move to doing a two leaf double wall.

Smart move!

Concrete planks seem pointless to me, I think I got hung up on an unimportant detail.

Rockwool (Roxul here in the US is the ubiquitous brand) is said to have much better absorption of sound than regular fiber glass insulation, is it true and worth the expense?

Not true, because you didn't define what you mean by "much better absorption of sound". That can mean many different things, some of which are directly contradictory.

Both mineral wool and fiberglass insulation work really well in acoustics, when used correctly. Arguably the very best product for many acoustic applications is OC-703, which is semi-rigid fiberglass. What matters isn't who makes it, or what it is made of, but rather a characteristic know as "gas flow resistivity". If that is in the correct range for the type of acoustic effect you are looking for, then you are fine.

Do different thicknesses of gypsum board on either side of a wall really absorb different frequencies or is it better to just go thick on both sides? I've read both

No, they don't. If you are LAYERING two different thicknesses on the SAME side of the wall, in order to build up a more massive leaf, then yes there is a slight advantage to using different thicknesses: However, that advantage is offset by the lost isolation, due to the wall having a lower mass than it could have had if it were all 5/8", and the lost isolation due to the greater flexibility of the thin stuff, and the lose isolation due to other minor issues. Overall, you are better off just doing everything with 5/8" fire-rated drywall.

Floating walls= This I understand but I'm wondering if there is an effective alternative to using the Mason Industries ND isolators that I could fabricate and/or implement myself; I've seen chit chat about neoprene this and neoprene that in varying applications (strips, pucks, what have you) but I really don't know enough about the physics to decide what is a sound idea (forgive the very, very awful pun) and what is not.

You might find this thread informative. It is about floated floors, but the exact same principle applies to floating walls:

http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173

- Stuart -