Garage Build/Room within Room Construction

Hello all. I've posted this thread on several forums. I'm looking for any suggestions for my small project studio and any problems there may be with my ideas. I would like to turn a portion of my garage into a control room/tracking room if that's even possible. I need to rehearse very loud b/c of the percussion. I have a very tiny area to work with. I'm looking for a room within a room design and I don't want any mechanical coupling with the existing walls as I feel this will eliminate the need for a permit. I am simply bringing in a couple of power strips from the existing garage duplex receptacles as most of my gear is low voltage(no guitar amps, etc.) My lighting will be with lamps. I need to make this room as temporary as possible so that when I do move I can at least disassemble the stud wall framing and keep. I know I will have to trash the drywall or maybe not? My wall design ideas are only from what I've gathered on forums like this. 5/8" drywall, green glue, 5/8" drywall, stud framing(staggered?) with R-13 then same for inside wall. It is on a concrete slab so I'm not sure if I really need a raised floor (there are no airports, subways, freeways, etc.) I don't have many ideas for the ceiling if it is different than the upright wall design. I have no clue as to the HVAC portion although but I do know HVAC contractors that could possibly run a duct from the nearby kitchen and I can feed the "structure" with a large diffuser to eliminate friction noise at the vent. I have a large garage door on the short side. I have included a drawing for review.

A room-in-a-room would be creating a four leaf wall system. If temporary is what you want, why not use plywood instead of sheetrock? I would also look deeper into your design. if you do not know what a leaf is, then you have work to do. Also, if you build this wall, any area that you cut it, like where the electrical panel is, will reduce the walls ability to contain sound. Good luck.

xSpace wrote:

A room-in-a-room would be creating a four leaf wall system. If temporary is what you want, why not use plywood instead of sheetrock? I would also look deeper into your design. if you do not know what a leaf is, then you have work to do. Also, if you build this wall, any area that you cut it, like where the electrical panel is, will reduce the walls ability to contain sound. Good luck.

Hey thanks for responding, I was beginning to think I didn't have proper forum etiquette or something. lol I did read on the terms and definitions in the "before you post" thread and you're right it is a four leaf system. I should have been more descriptive. I don't feel that plywood would be able to "soundproof" the room as well as sheetrock would, unless I am mistaken. I do want it temporary in the sense that I don't want it attached to the existing garage structure except for maybe hanging hooks to suspend the ceiling. Again I'm pretty clueless on the ceiling and floor portion of the project and I have searched on here. But I do need it to be as soundproof as much as possible especially on low freq's. I need to be able to play at all hours of the night without disturbing the family.

MDF would work better than plywood, though I'd still use sheetrock. BTW, this forum is where the inside-out wall design comes from (that I recommended to you in another forum), it's the idea of our gracious host....

concrete would be better then mdf would be better then plywood. my point is...temporary and that sketch reads like a low to no budget build:)

chamfer wrote:

But I do need it to be as soundproof as much as possible especially on low freq's. I need to be able to play at all hours of the night without disturbing the family.

Then forget cheap and forget easy to take apart - the frequencies you need tro deal with are the most difficult to handle - take the most mass - make sealed tight rooms critical (read dollar signs into all of that) and really have to be constructed as if they would last forever. Rod

Sorry if I interject some ideas and cross reference a bit here from another forum but I'm really feeling the modular idea jwl referred me to, which actually is from this forum. lol. Only problem is I've searched and searched and can't find the exact thread. If someone would be so kind as to post the link to the thread where it resides, I would appreciate it. Looking for the john sayers inside-out wall technique. Ok forget cheap and easy, haha. But I could definitely take my time building 4x8 sections at a time. Then me and my buddy could unfasten the framing from the floor and take with when it's time to move? Shouldn't be too heavy, don't answer that. lol . Good thing is that the bedrooms are all the way on the other side of the house and it's only a 1 floor residence. I'm just gonna cover up the hole I make in the section where the electrical panel is with some foam diffusors/absorption that I can easily remove to reach the panel. Good thing the panel is not flush with the wall, it sticks out about 6 inches so I can make a nice fit around it. I know there will be some leakage but good thing is it's on the left concrete wall leading to the exterior not the inside of the house. So is the "inside out wall technique" the better suggestion here? Oh yeah and don't make fun of the sketch. I drew it quickly on acad at work when my boss wasn't looking, while I was supposed to be doing plumbing gas, sanitary piping and domestic water floor plans and riser diagrams for a huge club. :D

check the design forum stickies - sideshow has a really nice build

Ok just a small update. I've gone ahead and removed the garage door opener and all the garage railings to have some extra space in this already limited area. I've closed up with spray foam, all visible light that was entering through the garage door opening crevices. I'm still a bit concerned as to leakage from the garage door. I might just hang mlv the width and height of the garage door back wall to assist here. (There will still be the back wall I'm constructing of the room within a room.) I've decided to float the floor b/c of the low freqs. prominent in the mixing material. I've ordered the auralex u-boats (should I use felt paper under it?) on which i'll be placing pressure treated 2x4x12 planks, r-19, then 3/4" plywood, then 5/8" dw, carpet padding, carpet. Please comment on this, I can't afford rubber mat, maybe I'm looking in the wrong places? What are my alternatives here? Clueless about the floor but now I want one. I'll be building staggered stud wall frame on 2x6 bottom plates, on top of the floating floor. I won't be using any rc's, but I've read and read and still can't get my head around the 1, 2, 3, 4 leaf systems. I swear I've tried. I'm going for (source side) 5/8", gg, 5/8", staggered stud framing with r-13 then repeat on outer wall. Is the idea to remove the outer dw layers and leave the insulation exposed to the existing walls on the garage? Inside/out technique? 3 leaf as opposed to four? Left side of the drawing is a painted cement wall, right side is a finished standard wall with dw on both sides which leads to the house. I've decided to forget the modular idea I had for portability and opt for better isolation. I'm not even thinking of ceiling yet. All I can say right now is 5/8", gg, 5/8", r-30. I've read so many informative threads on this forum and frankly so much of it goes over my head. I've gotten my head around a few concepts, but just when I'm learning about more mass= more isolation I learn about diminishing returns with extra layers of dw with the differing leaf systems. arghh. I've been reading and reading before this post to educate myself more, but it's no simple task absorbing what has taken the majority of you, a lifetime of work in this field to learn. On the plus side I was just donated about $750 of diffusers and absorbers by a band that parted ways. I know that doesn't do anything for me in isolating but now I've some control inside, when the time comes. I should have some pre-construction pics soon before the floor is laid.

Ok so I've begun construction. Going a bit slow due to funds but here are some pics. I'm thinking about treating that garage door with some 6lb density mineral wool from acoustimac. Then the studio wall sitting on the floating floor 6" opposite the garage door will be a staggered stud frame wall. with gg sandwiched between two layers of 5/8" dw on each side. Should it suffice? It will be really loud in there with percussion, drums and sub 40 hz synth basses and don't want any noise leaking out the garage door. First pic I floated the floor on auralex u-boats, the planks are pressure treated 2x4's and I screwed everything instead of nailing so that I can take apart easier when I move from here. Then in second pic I filled the cavities with r-13 fluffy fiberglass. Then I covered with 3/4" plywood, then 5/8" drywall. Still a few cuts left and I'm thinking of covering that final layer of drywall with osb wood chip subfloor. I 'm thinking my final finished floor will be a hardwood since I do want a combination of reflective and absorptive surfaces. It will be a multi-purpose room and for critical mixing time I just might throw down a big area rug and then roll it up when rehearsing and recording. Last pic is a preliminary sketch-up of the studio. Any suggestions or corrections are encouraged. Thnx.

I just ordered some of the mineral wool from acoustimac.(comparable to the oc-705, but it's 8lb/ft density). It's 2 in. thick and I want to cut that into 20"x24" pieces and slide that into the recesses you see on the garage door pic. There's a lip on the top and bottom of each recess that would hold it in place. I've read the terms/wall basics sticky many times and btw this link for the quad-leaf wall; http://www.audio-muziek.nl/audiotechniek/acoustics.pdf "can not be found" but anyway. If I'm understanding correctly the 2-leaf system, I should not build walls with 5/8" dw, gg, 5/8" dw on both sides of the walls that are on the floating floor, but rather 5/8" dw, gg, 5/8" dw only on the outside of each frame? As this creates a bigger air spring? (And that air spring increases sound isolation more than gg sandwiched between two 5/8" dw on both sides?!?) How is it a longer air spring if the distance between that outside wall of the "room within a room" and the walls of the garage are the same? Any links to pics or illustrations of this would help.

if the drywall is on the inside (of say a 2x4 frame (3.5"), and the outside wall of the garage is on a 2x4 frame (3.5"), and you have a 1" gap between frames, you have a ~8" deep airspace. if you put the drywall (2x 5/8") on the outside of the inner frame (to create say inside-out walls for treatments - and a 1.5" gap between frames) then you have ~3.75" of air. having drywall on both sides of the inner frame and a layer on the outside of the outer frame means you have a 3 leaf system which will have reduced isolation value at some frequencies when compared to a 2 leaf system.

The big issue with sound transmission for music is low frequencies. Have a look at fig. 5, pdf page 10 in NRC IR 586 The walls with two layers of drywall added (which means greatest mass also) have the worst low frequency isolation. Andre

Ok I appreciate the explanation guys and the informative pdf. I've done some changes to the sketch and will post it up tonight. I've removed the layers of drywall on the exterior of the frame and left the insulation exposed to create a longer air spring. Will fill up the stud cavities with rockwool/mineral wool. And will use 3 layers of 5/8" dw with gg in between for the source side. Do you guys reccomend using "stop gap" sealant for the little crevices and creaks around the garage door? I put some expanding crap foam in there and don't think it's going to do much in preventing noise leakage to the outside. I did put a good rubber seal on the bottom of the garage door.

Here are some revised sketch-ups. The hole in the wall on the right side when you walk in is for the panel access.Thinking of making a wooden box with insulation that I will stuff in the hole with a handle that I will just pull out when I need access to the panel. I hope I've come closer to the two-leaf design with this one, by removing the exterior layers of dw and adding them to the source side. I received my 8 lb/ft. mineral wool today and will affix those to the garage door.

much better. it cannot hurt to make sure everything is sealed as best as possible to avoid gaps which result in lower isolation.

Ok being a bit low on funds I've been going pretty slow with this but I've managed to put the mineral wool batts on the inside of the garage door and sealed all around the crevices with standard latex caulk. And I added the final layer of 3/4" plywood to the floor. (pics later tonight) Problem is; a person could be inside the garage speaking in a low volume and I can still hear them perfectly outside! This garage door is paper thin. I am very doubtful of not adding at least one 5/8" layer of drywall to the garage door to sandwich that mineral wool. I understand I am adding an extra leaf doing this, but considering how that garage door offers almost no insulation, I can't bear to think it would do more harm than good. I feel that if I go ahead w/o it and build the walls of my "room within a room", and then discover it's still not adequate, I will have to tear down that whole wall again. I will still leave the outside of the "room within a room" with the studs and insulation exposed to this new wall on the garage door. Is this acceptable? Thanks and pardon my stubbornness.

OK so here are the pics detailing my progress. Don't mind the pieces of drywall or lumber around the perimeter of the floor, just keeping them there till I use them later. I can't seem to find any viable and agreed upon options for dealing with thin garage doors on this site. Any links? I've done my bit of searching.

Ok got some updates for you guys. I've been building up the 2x4 stud framing with zero carpentry skills haha. But I've followed all the construction advice I've found here, online and with a couple of construction books. I used pressure treated sole plates, double pt top plates, 16 o.c. with fire blocking about 48" a.s.f. (above sub floor, lol, that's a new one)I used white pine for the long walls and yellow pine for the short walls. Since the heavy door will be on one of the shorter walls, I used this yellow pine for more strength. The very top plates of the long walls extend 3-1/2" beyond the lower top plate on either sides to interlock with the short walls for more stability. I used 3/4" mdf to sandwich the thick mineral wool (8 lbs./ft) I placed in the garage door recesses. Against the better judgment of most of you on here (as I was creating a third leaf, yet I would still argue that flimsy door could actually even be considered a leaf) This garage door sucked and had nooks and crevices all over the place and was super thin. Even now before the buildout of my room, , I can go outside now and hardly hear a thing when I have someone play the percussion inside. I sealed all the gaps around the mdf with "stopgap". I'm building the door frame with the double header construction (long side up) with 1/2" plywood sandwiched in between for increased strength for the heavy door and for more load bearing of the ceiling. The rough opening is 38" width with 82-1/4" height from floor. I got a quote from the depot for a pre-hung flush solid core 3'x6'8 door with 5-1/4" flat jamb for $174. The solid core slab of the same size was $46 but I am a bit worried about building a frame correctly and chiseling of the hinge recesses and door lock. I figured I'd just pay the difference. will lay the finished floor first though. Any suggestions are welcome.

oK moving along slowly here but have some more pics to show. things have taken long for many reasons but one thing is I've had to take down the ceiling joists on my structure 3 times due to changes in temperature causing warping. I opted for 2x6 for ceiling joists for rigidity. For hvac I will go with the Sharp Ultra-quiet Library Series compact floor standing ac(10,000 btu). It has an exhaust and I will run that out to the existing dryer exhaust in the garage and fashion a sealed box to throw air out. The structure became very solid after we started adding dw.