Plese excuse how I am posting all over but I'm not sure how to get this all under one thread This is in reference to my post regarding Vibrations Studio Build.
MY QUERRIES ARE ABOUT “MAM” AND “3 LEAF SYSTEMS”:
FIRST: I intend to do my new construction “building shell” to inside space like this:
New const. from outside in:
1. stucco
2. 11.25” concrete and rebar filled Styrofoam blocks- (so that’s a sandwich of 1.625” styro-8”concrete-1.625” styro)
3. 4” air space (no connection of wall to independent slabs either)
4. 2 layers 5/8” sheet rock on “inside out” 2”x4” stud wall filled with 703 insul.
5. then variations of acoustic cloth and slat resonators as needed for tracking room+/control room wall surfaces.
(I’m in the woods so noise going in or out is not much of an issue relatively speaking BUTTTTTT! …)
{QUESTION #1: Am I creating a 3 leaf system with the styro-concrete sandwich plus interior wall that will cause resonance and other problems??}
( There would be a big savings in my situation here if I can use the styro block exterior wall construction over standard stick build/poured wall/block/brick.)
SECOND:
When I encase my new structure around the existing house, again I have 3 leaf questions.
Existing house structure from inside out to new construction:
1. 5/8” painted sheetrock
2. plastic vapor barrier
3. 2”x6” stud walls 2’ OC filled with 6” standard fiberglass insulation
4. next is OSB (“wafer board”) sheathing
5. then there is Tyvec house wrap
6. and lastly vinyl siding
The abutting/encasing new construction (control room and air lock/stairs) will have the 4” air space between the existing house wall (which will not have styro/concrete wall here, also no connect to new slab) and the new construction.
{QUESTION #2: Will I need to remove the existing OSB to once again avoid the potential 3 leaf problem??}
(I’m assuming I need to remove the vinyl siding and tyvec)
If I do, the complete system structure would be would be as follows:
From outside in:
1. 5/8” painted sheetrock
2. plastic vapor barrier
3. 2”x6” stud walls 2’ OC filled with 6” standard fiberglass insulation on it’s own footer with new footer below it supporting (because the new construction goes down to the ledge below for extra room height for studio space).
4. pourous cloth to cover the exposed insulation in entry area
5. 4” air gap with no connection between existing house footer walls and new construction independent slabs
6. 2 layers 5/8” sheetrock (on “inside-out” wall)
7. 2”x4” “insideout” stud walls filled with 703 insul.
8. cloth/slats
If I remove the OSB I have to accommodate with “let-in/hurricane bracing” on the abutting house wall for structural integrity.
Any thoughts are welcome from anyone!!!!
“MAM” AND “3 LEAF SYSTEMS”:
Originally posted at johnlsayers.com, topic 9977.
if isolation isn't too much of a concern, the 3rd leaf is really only going to reduce isolation, not necessarily introduce unwanted resonances in the room (unless something is vibrating loosely or somehow you hit the right combination of things to cause it. by dampening the air cavities with insulation you'll reduce the chance the cavity resonances have any perceptible impact.
thanks much Gullfo :D one less detail to be concerned about at this point. I'm not too worried about loss of isolation in the wall that connects to the house (ie. back wall of cr and where stairs come down (air lock of sorts). I still have worries about loss of islolation posssibly due to the styrofoam -8" concrete- styrofoam of my 3 other outer walls creating a third leaf with the interior "inside out wall". I'm in the woods but my wife may choose to mow the lawn or create other low frequency noise outdoors that might pass into the tracking rooms if lowered isolation is sginificant there due to possible 3 leaf conditions.
Do you think the styro/concrete wall will create much of a problem with the mass of 8" of concrete between the styro sandwich with no air space between? Or does this solid wall system of styro-concrete- styro act as one leaf only??
I'm traveling on vaca right now but checking in regularly. This is my ideal vaca with so much time to plan for the build this spring. Thanks much!
in the case you describe with inside out walls, you shouldn't have a 3rd leaf problem since the interior wall of the inside out wall is treatment and not really a boundary per se. it would be different if the walls were drywall-frame-drywall-air-styro-cement-styro which is 3 leaf. instead you have treatment-frame-drywall-air-styro-cement-styro so for all intents 2 leafs.
Excellent and great to hear! That really moves me ahead in the design. You're the best Gullfo and thanks for the quick reply :D ,jp