another triple leaf ?

[krytikal1]

i have been reading through the threads here and on some other sites, and am just trying to understand some things about triple leaf a little more. like 6666666's question on an earlier thread, how much space is necessary between walls/leafs to render it not a problem.

......i am thinking of putting a new control room in a space that is currently 21l x 17w x 10h. i can build any way i want within this space, but obviously want to get the most out of it as possible. i have another 5x5 space adjacent for the machine room, so that portion won't be a problem.

the question is..... if the new walls are parallel to the existing exterior walls, is it worth the expense to remove the sheetrock on those walls and remove the triple leaf problem? the current exterior walls are more than likely only sheetrock - 2x6 - exterior siding. there would be no way to add additional layers to the outside of the existing wall, and i'm not certain if there is any existing insulation in the exterior wall.


thanks all in advance,

K

[bpape]

Yes - it's worth taking off the old drywall to avoid the problem.

The previous question related to a wall in another room rather than having 3 hard surfaces separating 2 rooms.

Bryan

[krytikal1]

thanks bryan!

K

[avare]

Hang on with taking it off. The first thing to do is check if there is insulation in the walls. If not, the biggest gain will filling them with insulation.

How much space will there be between the inner two leafs? Have a look at pdf pages 71 and 72 in NRC 1R 811. Each addition of mass improved isolation. The two middle ones were with triple leafs also had significant space.

The advice for avoiding triple leafs is in new construction. Notice page 72 that the system with the greatest isloation was a double leaf AND took up the least space. Also that method 1 and method 4 for improving sound isolation use identical materials!

What is thee spacing of walls and what are planning to put the inner ones?

[bpape]

If it's in the inches range instead of feet, it's still worth doing. Agreed on the insulation - but you'll have to pull down some of the sheetrock to do that anyway if it's not insulated.

Bryan

[krytikal1]

i'm sure it will be inches. the perimeter is only 21l x 17w. i will need as much of that room as possible to build a halfway decent mix room. unless i was able to splay the walls rather extremely, i can't really see it being much more of a distance than that.

K

[avare]

Kritikal1:

Bpape and I are not giving contrary information, what we need is details!

Bpape:

If it's in the inches range instead of feet, it's still worth doing.

? Did you look at the TL data I referenced in IR 811? Method 2 added a 4" space and increased TL up to 30 dB (at 500 Hz). All four designs are limited by m-a-m resonance at the low end. Or am I missing something in your thinking.

Andre

[krytikal1]

nothing missing. i will review the info you gave me for sure. i have just been enjoying a few well needed days at the coast with my family. other than a check in here and there with the email, i am trying to stay digitally free.

i will check it out this weekend, and give you a few more details. like i said, 21l x 17w is my perimeter, and i would like to maximize that space as much as possible. i will poke some holes in the walls and check out for current insulation and other hard facts. i haven't yet committed to anything, as i want to build the truest room possible within those boundries. i am still working on the hvac system needs as well, which might affect a few of the wall placements.

thanks guys, get back to you in a couple of days.

K

[bpape]

Andre

I just perused it quickly. I'm not seeing any data for the additional depth WITHOUT the interior layer.

Bryan

[avare]

Originally Posted by bpape

Andre

I just perused it quickly. I'm not seeing any data for the additional depth WITHOUT the interior layer.

Correct. The section of the report deals with what can be done to improve isolation of an existing ceiling. The thinnest construction has the best isolation. The ones with triple leafs take up more space, use additional material (studs, u-channel) and achieved no improvement over the two leaf design.

More significantly is the difference between method 1 and method 4. Clear triple leaf effect.

Andre