Hello,
1st time post and hopefully I've followed the rules properly with my 1st post here.
I'm building a new studio space inside an existing garage. The space will be used for personal tracking and mixing. I am a sound designer and mainly work with electronic & ambient sounds with the occasional need for tracking live instruments. We are located out in the country, in Northern, IL, with the nearest neighbor quite far away. My needs for isolation are more about keeping outside sounds from coming in. The occasional car goes by, train horns can be heard from a couple miles away. The property is very wide and open, so very distant sounds can be heard quite well. We abutt a nature area and there is more sound from nature and birds here than by humans. The sandhill cranes, get very noisy when right outside the garage. Don't get me wrong, It's very cool to have all this here, like Mutual of Omaha's Wild Kingdom. It's still sound though, and I'd like to keep it from penetrating the studio space as much as I can. Since I'm way out in the country, my isolation needs are not great, in terms of keeping sound from existing the structure. I do however want to control the sound well enough to be able to get proper mixes and keep the exterior sounds to a minimum
I'll be using the existing South & East wall and adding the North & West walls on the inside, to give me a finished room size of 17'-6" long x 11'-6" wide , 8'-4" high. The existing exterior wall makeup is: vinyl siding over 1/2” OSB nailed to 2x4 studs. I do need to fir out the existing exterior walls in order to get them flush to the existing concrete gas curb. The garage floor is a 4” pour of concrete. The roof sheeting is 3/4” OSB. The existing South & East exterior walls have single pane slider storm windows in them, I know that these are going to be my weakest link, along with the entry door to the new studio space. Since framing them in is out of the question, I plan on replacing them with insulated vinyl clad windows and making 705 plugs for them, to use when needed. It's a sacrifice I'm very willing to make, since the views outside are very inspirational. The door, well, I need to work that out still.
I've already started the construction process. The carpenter has installed the floor, ceiling, and walls, using conventional techniques, which is fine by me. I totally understand that there is going to be some flanking issues and that I have some current decoupling issues, but my budget is small $4 – 5k, and my isolation needs are not huge, but they are there, so I'm using what resources I have and making the best of it. The carpenter is very skilled in conventional framing and trim. He's doing very nice clean, square, plumb work. The floor system consists of 1x4 pine sleepers at 24” O.C. Tapcon;d directly to the existing slab, with 3/4” solid pink foam between the sleepers. Then a layer of 3/4” OSB has been screwed down to the sleepers. Yes, it would have been better to screw the 3/4” OSB directly to the slab, but winters here can be brutally cold, so I opted for insulation under the floor. It's another sacrifice I'm willing to make, in order to help stay warm in the winter. Hopefully it's not a game stopper. The walls are 2x6 @ 16” O.C. And the ceiling joists are 2x8 @ 16” O.C. The top of the ceiling joists are covered with 1/2” OSB as are the exterior sides of the newly framed walls. My wall section will be a simple 2 leaf design. More than likely, I'll add a layer of 5/8” drywall to the 1/2” OSB on the exterior side of the new walls. I'll be using double 5/8” drywall on the interior. I've attached a few photos of the raw space before construction, as well as some work in progress images.
My questions are about adding mass to the existing exterior garage walls:
can I add 5/8” drywall between the existing studs on the existing exterior garage walls, in order to add mass to them?
Will this negate the 2 leaf design?
I should caulk fully around all the stud / OSB joints before applying the 5/8” drywall and then caulk the new drywall in?
I should add a layer of 6mil vapor barrier to the inside face of the existing 1/2” OSB before I add the drywall between the studs of the existing exterior 2x4 walls, in order to prevent mold / moisture correct?
adding mass to existing walls question
Originally posted at johnlsayers.com, topic 15987.
welcome! you should add the mass between the joists on the exterior wall not on the stud because you're creating a triple leaf that way. are you building your isolation walls on the concrete or the raised floor? looking at the pictures it looks like you used 1x sleepers with some foam insulation - is that damped enough to avoid adding resonances? what is the plan for the isolation ceiling? are you putting another set of joists on the isolation walls or just putting isolation clips and hat channel on the joists you put the OSB on?
overall - have you measured the acoustics to determine what levels and frequencies of noise are coming in?
thanks for the Welcome...perhaps I may not have been clear. My plan was to add mass between the existing exterior wall studs. As you saywelcome! you should add the mass between the joists on the exterior wall not on the stud because you're creating a triple leaf that way.
The isolation walls are built on the raised floor. The floor plates are fastened through the OSB directly to the 1x4 sleepers that are tapcon'd into the concrete. The raised floor is pretty well dampened, I do plan on adding some felt over the 3/4" OSB and then solid hardwood flooring. I'm pretty confident that if resonance has been added it's going to be very minimal at best. I fully understand that this isn't the optimal situation, given the fact that I could have just fastened the 3/4" OSB directly to the concrete, but as I say, the winters here in our area can be brutally cold for days on end, hence I chose to raise the floor off the cold concrete. Is this setup a real MAJOR problem?are you building your isolation walls on the concrete or the raised floor?
I'm still trying to work out the materials for the ceiling. Currently there is 1/2" OSB on top of the new ceiling joists. My Current plan is to fill the joists with r30 kraft faced batts then vapor barier over that, then hat channel then drywall.what is the plan for the isolation ceiling?
I'll be using clips and hat channel on the 2x6 studs I put the OSB on.are you putting another set of joists on the isolation walls or just putting isolation clips and hat channel on the joists you put the OSB on?
Now that you mention this, I should probably buy a meter and check the current sound levels coming it. Thanks for the tip! and thanks for the responseoverall - have you measured the acoustics to determine what levels and frequencies of noise are coming in?
just checking you were aware of the potential for the floor to make things worse but per your cold weather considerations it should be fine - just ensure it's full damped. missed the "between" on the studs - my mind read "on the studs"... you're good there.
thanks for the follow-up and review, It's much appreciated....onward with the build out
A simple reality check....you guys have many, many homes built on concrete slabs that have none of this extra effort and the interior climate remains good...the HVAC is going to be the helper, the damped concrete, the assistant.
Building a drum head is what you are doing...my suggestion, read better information:) and lose the supposed heating benefit of this elevated wood vibrating floor.
"I do plan on adding some felt over the 3/4" OSB and then solid hardwood flooring. I'm pretty confident that if resonance has been added it's going to be very minimal at best."
It exists...it isn't something you add, the materials have the properties and the properties of the few generate the property of the whole...E.G., a drum head:)
not sure he's building a drum head unless the flooring isn't fully damped. using 3/4" sleepers is a lot different than using 2x6 on edge with neoprene pucks...
That's where I'm coming from as well...by the way, love the Db meter tip you gave me Gullfo, I'm taking levels during the day at different times and again on Sunday, which seems to be the busiest traffic day with people all going out for Sunday drives in the country..:) this should give me a good sense of what I need to do with the walls before I start hanging rock. Great tip!not sure he's building a drum head unless the flooring isn't fully damped. using 3/4" sleepers is a lot different than using 2x6 on edge with neoprene pucks...
It really is a lot different, that is a typical installation of a hard wood flooring, real wood not engineered, and the hollow sound generated is noticeable. Still, beyond if it is this or it is that, the concrete is the better product, it has the mass. Anything after that is going to change the way the floor interacts with the room, pucks, etc. it's money spent with little advantage, saving the manufacture that suggests it or those that support this type of light weight framing over a mass laden/damped, existing floor. It is beyond me as to why there is so much support for a basic breaking down of the initial ingredient that isolation requires...mass...?not sure he's building a drum head unless the flooring isn't fully damped. using 3/4" sleepers is a lot different than using 2x6 on edge with neoprene pucks...
Mass is king...
i don't disagree - i prefer polished and stained concrete whenever possible. that said, the owner said the concrete floor gets too cold to work and decided to cover it with an insulation layer. choices...
Certainly it gets cold...he is up state, in a garage, no heat...it all stands to reason. But ask the OP if they have a concrete floor on the interior of the homes in this area with a wood barrier...I think not :)