Originally Posted by AnnapolisSony
I am in the planning stages of my “2.0” at this time and I am looking for some general soundproofing advice before I move any further along (I haven’t even started an official thread yet). Final thickness of walls and ceilings will obviously affect my construction/framing plans so I am turning to experienced forum members for advice so that I can continue moving forward planning with my contractor.
Hey there. This looks like it's going to be an interesting build. Before I dive in with my 2 cents, allow me to mention two house-keeping items: 1) Thank you for doing such a great job framing your scenario and questions right out of the gate. I'm sure the fact this is going to be HT v2.0 for you has a lot to do with it, but I'm sayin' that anyway. Nice diagram too. 2) It's a tough time of year right now to get folks' attention on these matters (myself included). It seems like most of my neighborhood is on vacay this week, and I don't blame them!
Now... to the topics at hand....
[quote]I am up against a few challenges using this space - the biggest one being lower-than-normal ceiling joists @ 91” throughout my basement.
The overall dimensions of this space will be 12’ 5” W x 21’ 5” L
…give or take a few inches and it will be more of a dedicated room this time around. When I built my room in my former house back in 2013, I began with mostly already-finished walls and ceilings and the space was a more open living space with a home theater set up within it (it was at least 2 1/2 times larger with 8’ ceilings). [quote]
Width is a little tight, but do-able. Are those your gross dimensions (stud-to-stud) and joist-to-concrete floor? Just wondering how much will be shaved off for various things.
Do you know what your state/local municipal required minimum floor-to-ceiling height is, whether it is measured finished or unfinished, and what the criteria for measuring are? It would be good to know ahead of time. Don't count on your contractor for that. The homeowner is on the hook (even if you paid someone to screw it up for you). If you plan on not getting a final inspection, it may be a non-issue. I'm not here to preach to anyone about building inspections. Just sayin' those are things you should take into consideration.
[B]The #1 priority for me is soundproofing this room... without breaking the bank.... minimize sound out/sound... please the wife upstairs (on the 1st floor)... furnace and a laundry area just outside of the space.
Priorities: $, WAF, noise. Check.
... have some flexibility... not one existing wall of the room is built up against an exterior/foundation wall.... ducts/returns in between ceiling joists in the room.... relocating the vent ducts/returns is not an option..... new lighting.... Central air/heat... rough in work....
HVAC... lighting... the whole 9-yards. Good.
.... I have lettered each wall (A-F) so that you all know which wall I am referring to in my descriptions below:
Before we get into that, what is on the outskirts of the room-to-be? You mentioned Wall A and the 18" gap w/gas lines. What about the other spaces. I'm especially interested in better understanding the "south" wall (bottom of diagram) that says, "staircase edge wall." Please elaborate more on what is (or will be) on the other side of your perimeter walls, other than Wall A.
... front of the room. The back of this wall is insulated with R11 in stud bays but does not have drywall on the backside.... I have approximately 18” between it and the exterior foundation wall behind it. I know, no bueno for soundproofing. This thread here
Unless I missed something, I believe you may be reading too much into that thread. You do not have a triple-leaf scenario if I understand you correctly, but I'd like to verify. My understanding is on Wall A you do or will have, layered from inside the theater, out:
- Drywall -
- Green Glue??? -
- Drywall -
- Stud wall -
- 18" air gap -
- Foundation wall -
Is that correct? If so, you are GTG. What you want to avoid is something you mentioned you cannot do anyway - applying drywall to the outside
of the stud wall of Wall A (nearest the foundation wall). That
would give you a triple-leaf situation and bad juju
In fact, an 18" air cavity there is a bonus. You could stuff it with insulation and make it even better, but I would advise against it since it is contrary to your rule no. 1 (minimizing cost). That's a lot of insulation. Plus, it is likely unnecessary. Some
insulation would be a good idea (I would say required, to reduce reverb off the concrete wall behind your screen), but you don't need 18" + 3.5" stud wall thickness worth.
That said, the finished wall continues across my basement - to the other side - with the same amount of space running behind it the entire way. When natural gas was added years ago, they ran 2 gas lines straight through the space and secured both of them to the back of the exposed studs about 80” above grade.
Ok. Now, here is the part where my antenna go up. The NG line. You MUST ensure you can access that if you ever need to. Nothing fancy, but you need a plan (at least). It doesn't have to be an easy plan, but you need a contingency plan. It's no different than if you had to rip out a wall elsewhere in your house in the future for whatever reason, except it's your HT room and this room will be built differently from the rest of your home. I would suggest that at a bare minimum you have drawings that show where things are, so you know what to do should that ever become an issue.
Also, please make sure the pipe is properly protected per code (just saying this since I don't know exactly how it's run atm).
I am hesitant to install in-wall speakers on Wall A for obvious reasons (even will backer boxes) so the plan for now is to go with on-wall Triads for the front L-C-R.
Why? You have an excellent cavity that many people would be jealous of. Speaking of which... have you considered the option of moving the wall further back toward the concrete foundation wall (obviously including moving the gas line)?
As-is, it sounds like a great space for in-wall speakers (unless I'm missing something, as previously mentioned).
I have not given up on the possibility of in-walls behind an AT screen (if I go the PJ route) but I have to get this soundproofing issue resolved before I can even consider that. I put in a contingency for an additional 4.25" inside Wall A in the event that it is recommended that I build another wall for soundproofing. It will be virtually impossible to build another wall between the existing wall and the foundation wall due to the gas lines and a water line that run behind.
And to that point, perhaps moving Wall A is not an option, period (aside from potentially being a cost you don't want to take on).
Either way, if you can fit backer boxes in the stud-Wall A, I would do it. I don't see any reason not to unless there is an encroachment where you would want to place them. BTW, I have also drunk the Triad Kool-Aid. They work very well (Triad in-walls). Speaking from experience.
Ceiling height in the front section of the room should be somewhere around 89-90” depending on how thick I go on ceiling.
What is the best way to approach soundproofing Wall A?
Ceiling height should be OK.
The big concern I have for Wall A (besides the utilities behind it) is that I would bet the wall is built like a normal house wall. Is it load bearing? I would presume not, but it's not good to be presumptuous about such things. So, here's the clincher... are you interested in building a true "room-within-a-room," or no? And if yes; clips or double stud???
See above for other suggestions on Wall A. Other than above, the usual double-drywall-Green Glue sandwich recommendation.
This wall is obviously yet to be constructed but it’s purpose is obviously to close off the room from the other half of the basement (and staircase). A 30” doorway will be installed in this wall with a solid core door (this will be the only door in and out of the room).
I need to break here for a late dinner, and will return w/response to remaining questions in a few. LoL.