Do I really need to float my walls???

Posted: Fri Feb 09, 2007 8:10 pm

Ok i've been over the floating floors debate over and over, and concensus is that unless you have exact engineering and data to construct the right floor, doing it improperly will actually make things worse. And for it seems, %95 of people building studios in the garage conversions like me, it is unnecassary for general garage band use.

But, how about those walls?? Do i really need to float those too?? If so, why and how much of a difference will it make in a room in room design???

Posted: Fri Feb 09, 2007 8:40 pm

4tuneit1 wrote:

Ok i've been over the floating floors debate over and over, and concensus is that unless you have exact engineering and data to construct the right floor, doing it improperly will actually make things worse. And for it seems, %95 of people building studios in the garage conversions like me, it is unnecassary for general garage band use.

But, how about those walls?? Do i really need to float those too?? If so, why and how much of a difference will it make in a room in room design???

While I'd be interested to hear what people over at John Sayers have to say about it, I personally question the veracty any claim that imporperly floated floors would make things "worse". At best, I believe, it would be unity gain... As a lower performance bound, you would get no benefit... but it wouldn't actually make things worse.

Floating a floor properly hinges primarily on one major criteria, other than making sure the floor doesn't get accidentally "shorted" to the wall - there has to be a uniform 1-4 to 1/2 inch gap seperating the plywood or OMB floor from the wall.

That primary criteria being loading the neoprene to the exact percentage of compression, which isnt even an exact amount anyway, because nobody has eve determined the exact amount. It is merely a generalized range of optimailty, give or take 15 percent.

If you screwed up your loading calculations and under or overloaded the pucks, causing too much or too little deflectuion... its not going to make the decoupling worse, I dont believe. Its just going to be a waste of time and money.

Secondly.... by "floating" walls.... do you mean:

(a) actually floating the "base plate" of the wall (thats the 2x3 or 2x4 plate which your wall studs are attached to,

(b) or do you mean making sure the inner wall is decoupled from the preexisting house wall?

The inner wall should absolutely, positively, be decoupled.

Whether you choose to float the base plates of the wall is optional depending upon what kind of isolation you are realistically looking to achieve. Its certainly easier and much less costly and less time consuming than floating a whole floor... so its optional. Its not a question of if its necessary. The operative question is.. do you want to do it. The fact that you dont want to float the floor kind of indicates that your not looking to make a big deal out of the project, hence floating the wall plates is likewise may be overkill for your purposes.

Do however check your design repeatedly, to make sure the inner wall is decoupled as best as possible from the existing house wall.

Posted: Fri Feb 09, 2007 9:54 pm

4tuneit1 & Mises,

Welcome to RO!

Pretty spot on advise there Mises... for a particular case. Which therein lies the rub.

The real issue is not whether to float or not float... at this juncture. Not being at smart-ass, but I don't think there's enough detail to make any kind of advice valid... other than to say it's a generality.

There's a couple of minor details (NOW I'm being a smart-ass Very Happy

) to answer first...

How loud will it be in the recording space?
How close are your neighbors?
How much you willing to spend?

Just a couple of comments on the above... If you're recording thrash bands and your neighbor is 25 ft away... no amount of money is going to seem like enough to stop problem frequencies.

However, folk guitar and vox with neighbors 25 feet away... no need to do much other than seal the room from outside noise.

It's an obvious drill, but you really do need to supply more details before accurate advice can be given as to any particular construction method.

Max

Posted: Sat Feb 10, 2007 9:01 am

Mises wrote:

[ I personally question the veracty any claim that imporperly floated floors would make things "worse". At best, I believe, it would be unity gain... As a lower performance bound, you would get no benefit... but it wouldn't actually make things worse.

Mises,

actually the quote isn't that you "would" make things worse - but (rather) that you "could" make things worse. (I know this to be the case because it is I who made the statement in question).

You can take this up at John's if you wish - and will find that they are in agreement with me - as is Mason Industries - one of the leading companys in the field of isolation supplies who wants to sell you those special isolating pucks and other iso gizzmos.

What you are essentially doing is creating a drumhead - and it's very possible that this head could (if it's improperly constructed) amplify certain frequencies in addition to not isolating well.

Quote:

Floating a floor properly hinges primarily on one major criteria, other than making sure the floor doesn't get accidentally "shorted" to the wall - there has to be a uniform 1-4 to 1/2 inch gap seperating the plywood or OMB floor from the wall.

That primary criteria being loading the neoprene to the exact percentage of compression, which isnt even an exact amount anyway, because nobody has eve determined the exact amount. It is merely a generalized range of optimailty, give or take 15 percent.

If you screwed up your loading calculations and under or overloaded the pucks, causing too much or too little deflectuion... its not going to make the decoupling worse, I dont believe. Its just going to be a waste of time and money.

I assume the statement "other than making sure the floor doesn't get accidentally "shorted" to the wall" refers to coupling with the existing structure - and not the inner wall of a truly isolated "room with a room" -

if my assumption is correct - then yes I agree completely. If (on the other hand) it's the 2nd - then not really - the greatest isolation is acheived by floating the walls on top of the isolated floor itself.

BTW - just for the record........ - if it's airborne sound you're concerned with - and you don't design your floor to a center frequency of somewhere around 10Hz - then you may as well not bother to build it at all.......

Floated wooddecks are pretty handy at isolating sounds that are impact in nature - but lousy for loud airborne noise - especially low frequencies - AND - seeing as low frequencies are the ones that are the most difficult to isolate - your styatement about a "waste of time and money" applies even if the pucks are loaded properly.

For real isolation you require mass - lots of it - and a rigid structure. Yo can get pretty good with a lift slab of concrete around 5" thick.

Quote:

Secondly.... by "floating" walls.... do you mean:

(a) actually floating the "base plate" of the wall (thats the 2x3 or 2x4 plate which your wall studs are attached to,

(b) or do you mean making sure the inner wall is decoupled from the preexisting house wall?

The inner wall should absolutely, positively, be decoupled.

Whether you choose to float the base plates of the wall is optional depending upon what kind of isolation you are realistically looking to achieve. Its certainly easier and much less costly and less time consuming than floating a whole floor... so its optional. Its not a question of if its necessary. The operative question is.. do you want to do it. The fact that you dont want to float the floor kind of indicates that your not looking to make a big deal out of the project, hence floating the wall plates is likewise may be overkill for your purposes.

I would not necessarily agree with the statement you make above. More specifically "The fact that you dont want to float the floor kind of indicates that your not looking to make a big deal out of the project, hence floating the wall plates is likewise may be overkill for your purposes."

WHen I constructed Power Station I did not include floated floor assemblies - and not because I was not looking to make a big deal out of a commercial facility that the owners paid 450 grand for a new building to put it in - and then another 450 grand for the room within the room.

I was very serious - BUT - it was not necessary for me to do this to acheive excellent isolation when I could get the same results by simply isolating the various concrete decks from one another.

In the case of a basement studio within one's home - the floor and foundation walls are usually pretty well damped by the earth they sit on and are backfilled with - you won't generally get a lot of transmission through those sources........

Personally I agree that it's probably overkill to bother floating the walls as long as they're isolated fromthe existing structure - but I do not view the lack of a floating slab as being indicative of the attitude of the person building the room.

Quote:

Do however check your design repeatedly, to make sure the inner wall is decoupled as best as possible from the existing house wall.

Agreed - 110% critical.... this is the ost important part of all......... and there really isn't any reason to have this be less than 100% - it doesn't cost any more to do it right than to do it wrong.......

Sincerely,

Rod

Posted: Sat Feb 10, 2007 1:47 pm

THanks for the input guys.

For reference i am on John Sayers site here:

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=7652

Basic run down-

Garage conversion in process. I have beefed up all exterior garage walls as explained in the thread, and will be building a room in room design. I will be using the space primarily for drum practice and my bands practice space. We play at around 100db but peaks up and down depending on the song. Neighbors are a consideration though they are musicians themselves, and the closest is about 30 feet to my garage space. So what i expect is about an STC65 wall design with a mild 3 leaf attic situation that i hope to reduce by using GG on the ceilings and walls.

I will be building a drum riser and amp cabinet risers for the bass and all the room treatments, corner bass absorbers, clouds, slat resonators, and reflection point absorbers. Ceiling will be 2" 703, floor will be stained concrete or laminate. I am not looking for an acoustically perfect inner room, because of wife comprimises, i must keep the walls un-splayed. But i will make moveable panels if necassary.

Framing is 2x4 24"OC and will be insulated with r19 pink full fill in the cavities and ceiling. Existing ceiling is 2 layers 5/8 rock and 12" blown cellulose.

Money wise i am budgeting $5,000 and have spent about 1600 just on the outer wall beef up, tools, etc... I do not have the budget for a floated floor, nor the desire to want to build it for now. If i see in the future it is absolutely needed, i will re-approach it and design it into my build.

So back to it... IN my situation where recording is not a primary issue, where neighbors are an issue (but considering the room in room design), how great are the benefits to going through floating the walls properly calculating load/deflection vs. hard anchoring to the 5" slab??? I grasp from Rod that it is not that much of a prescient need?

Posted: Sun Feb 11, 2007 9:38 am

No it is not - not enough bang for the buck.......

Rod

Posted: Sun Feb 11, 2007 12:09 pm

I'm just going to forego reading the other replys, mainly because I'm lazy. This is what I did when I built my studio. It was the most cost effective way, in my opinion. And most importantly, it works!

I framed the walls in applying silicone caulk to the floor before securing them. I used Owens-Corning insulation between the studs, I think it's called "Quiet-Zone" or something of that nature. Then, two layers of 5/8 drywall on each side with mass-loaded vinyl in between the layers on the inside of the room. Then treat with acoustic foam. That's it for the walls. No staggered-studs, no floating.

The results have been excellent. My only weak point now is the door. Other than that, I can have a full band in the live room with very little leakage.

This maybe isn't to "spec" but for your application it should suffice. The doors and windows are the tricky parts. Soundproof doors are not cheap!

Posted: Sun Feb 11, 2007 7:24 pm

backinthelab wrote:

I'm just going to forego reading the other replys, mainly because I'm lazy. This is what I did when I built my studio. It was the most cost effective way, in my opinion. And most importantly, it works!

I framed the walls in applying silicone caulk to the floor before securing them. I used Owens-Corning insulation between the studs, I think it's called "Quiet-Zone" or something of that nature. Then, two layers of 5/8 drywall on each side with mass-loaded vinyl in between the layers on the inside of the room. Then treat with acoustic foam. That's it for the walls. No staggered-studs, no floating.

The results have been excellent. My only weak point now is the door. Other than that, I can have a full band in the live room with very little leakage.

This maybe isn't to "spec" but for your application it should suffice. The doors and windows are the tricky parts. Soundproof doors are not cheap!

So basically you created 4 leaf room and it sounded ok outside? How far were your neighbors? I will be probably using and elastomeric caulk for the base plates in lieu of floating them. I think this is a reasonable comprimise that will for the money offer some benefit (maybe slight) but not increase the time and labor to truly float them. My idea was to caulk the underside of the base plates uniformly with a bead of elastomeric and then place them on the ground on shims that could be removed after the elastomeric has cured to a pre-determined height off the slab. Then i would bolt the base plates down compressing the caulk as it were a rubber pad. The compression would be inexact, and probably exceed its compressive tolerance, but minimally it would act as a buffer for some transferance of vibrations. Is your acoustic foam fire rated???

Posted: Sun Feb 11, 2007 7:32 pm

backinthelab wrote:

I'm just going to forego reading the other replys, mainly because I'm lazy. This is what I did when I built my studio. It was the most cost effective way, in my opinion. And most importantly, it works!

I framed the walls in applying silicone caulk to the floor before securing them. I used Owens-Corning insulation between the studs, I think it's called "Quiet-Zone" or something of that nature. Then, two layers of 5/8 drywall on each side with mass-loaded vinyl in between the layers on the inside of the room. Then treat with acoustic foam. That's it for the walls. No staggered-studs, no floating.

The results have been excellent. My only weak point now is the door. Other than that, I can have a full band in the live room with very little leakage.

This maybe isn't to "spec" but for your application it should suffice. The doors and windows are the tricky parts. Soundproof doors are not cheap!

So basically you created 4 leaf room and it sounded ok outside? How far were your neighbors? I will be probably using and elastomeric caulk for the base plates in lieu of floating them. I think this is a reasonable comprimise that will for the money offer some benefit (maybe slight) but not increase the time and labor to truly float them. My idea was to caulk the underside of the base plates uniformly with a bead of elastomeric and then place them on the ground on shims that could be removed after the elastomeric has cured to a pre-determined height off the slab. Then i would bolt the base plates down compressing the caulk as it were a rubber pad. The compression would be inexact, and probably exceed its compressive tolerance, but minimally it would act as a buffer for some transferance of vibrations. Is your acoustic foam fire rated???

Posted: Sun Feb 11, 2007 7:40 pm

My neighbors are close, about 15 feet between us. However, this is in my basement so you have to take into account the 10 inches of concrete in foundation walls. The absorption within the basement is excellent, you can hear only muffled sound in the rest of the house (condo, officially).

The foam that I used is not fire-rated, unfortunately. But, as long as no open flames are present (such as candles), it's not a big deal.

It sounds to me that you're more than equipped to accomplish your goals. Good luck!

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