Studio above garage in bonus room- early planning

Hi all, This is my first post. I have been enjoying the site for some time. Reading off and on during the last year. I have really learned a lot. I've ordered Rod's book from Amazon. (ordered Feb. 20- not delivered yet.. and I'm in a bit of a dispute, but I do have a tracking number!) I donated to this forum for all the knowledge I've gotten already. I have a building permit, but I don't live in any city, and the inspections here are non-existent.... rural WV, USA! I will post pictures in the correct size directly to this site. But here are some pics on my web space. I write and record rock music. I can build an amp isolation box or use the vocal booth for guitar amps. I will mix and record acoustic instruments, bass, and keyboards, vocals, etc. I probably won't record acoustic drums in the studio. I might record acoustic drums about once or twice a year, either in the garage or basement, during the daytime, after I warn my neighbors and get their permission. But I don't plan on sound proofing those areas for that one day a year. I have two neighbors 120 and 150ft. across the street from the front of my garage. I'd like to be able to mix and record without me and the neighborhood interfering with each other too much... Our house was just built and we moved in. :D I am finishing the inside of the garage before I start on the studio. Before I know if I can "beef up" or build double walls, I'm trying to figure out how much weight my floor will hold and how bad the sound leakage will be through the floor and out the two garage doors. The studio is above the garage. The contractor used 12" tall TJI joists to span the 24' across the garage, with no beams or poles. 3/4" OSB above the joists and 5/8" drywall below the joists. I just called the structural engineer who works for the joist manufacturer. He said I have a L/400 span with 3/4" deflection at maxium 40 psf live/10 psf dead load. I think I may be a little screwed when it comes to weight. I'm worried that I can't build a room in a room, and I may be stuck with 1 layer of drywall on RC. :( If I address a couple issues, maybe I can start to design this darn thing! Any comments are appreciated. Does anyone know how to calculate if I can build double walls and ceiling, since I have 40/10 capacity? I wonder how much leakage will I get though my floor and out the garage doors? Without a post or beam under the floor, will the floor resonate like a drum and sound right out my steel insulated garage doors? Thanks

Finally got Rod's book in the mail yesterday. I had to get a refund on the first "lost" shipment and re-order. I've read to page 81, so far. Great stuff ...very well written and easy to understand. I've read a few books on building a home studio over the years, but this one is definitely the best! It's making me re-think where I put my studio. I do have a decent sized unfinished basement I could use instead. It has an 8' 8" height (13 rows of block). In the book, it seems as if I'm in for a tough road trying to get isolation in the raised wooden deck that is above my garage. But since I only track acoustic drums once a year or so, I'll not sure how much isolation I need. I could buy an V-Drum type kit for rehearsing. I can record electric guitars direct or in a vocal booth. I think the isolation problems would come into play more for mixing. I try to mix at moderate levels, but I occasionally check my mixes very quiet and pretty loud. I have a sound level meter I'm gonna do some testing with and a structural engineer is going to come over. I'll report back with the decibel testing from the neighbors' houses. If anyone has any helpful thoughts, please post 'em.

Welcome, britune! You're off to a great start in terms of education and engineering requirements. As soon as I saw the title of you're thread, I thought, "Oh-oh, here we go again... Roll up the sleeves and get ready to start typing about dead loads..." But you're already well along your way to appreciating these things. Your basement with generous headroom (many would kill for that extra foot-and-a-half you've got down there!) may very well be a more practical environment, considering weight issues alone. Of course, basement studio projects have challenges all of their own, but yours being new construction may be a benefit. I'm sure Rod's book has opened your eyes to many of the challenges you're in for, whether you build underground or upstairs. One immediate thought I have about your weight issue over the garage is that you may be able to substantially increase your load capacity by installing a beam in the garage that runs perpendicular to the joists, perhaps with a post or two in the middle. This would probably involve cutting a small area out of the garage floor, excavating down and around the hole, building a cage of rebar in the hole, then filling it in with concrete. Obviously, this is something for which you'd need the structural engineer's input. The one thing the bonus room has going for it is that it's currently unfinished, so with the support beam (and posts?) downstairs in the garage, "beef-up" would involve simply adding a layer or two of plywood on the upstairs floor and a layer or two of drywall below. Of course your structure-borne flanking will be an issue... So perhaps constrained layer dampening layer (Green Glue) can help with this. You're early in your design phase and you're thinking about this correctly. All too often we get posts from new home dwellers who have a design in their heads that just won't fly... Keep up your studies and keep us posted with your plans and/or questions. --Keith :mrgreen:

Hi Britune, I am actually headlong into a studio build very similar to yours. In my case, I built a 22 x 24 detached garage really for the sole purpose of utilizing the second floor as my studio. My current studio is actually very nice, however it is in the basement....which for me has not been the best solution. The lack of natural light, the difficulty with cooling and ventilation, the proximity to the rest of the house in terms of sometimes not feeling isolated enough and other times feeling too isolated, all posed enough of an issue to send me in this new direction. I will post some more detailed pics soon......but to familiarize you with my situation, let me give you a little overview. As I mentioned, the size is 22' x 24' which was dictated by the lot space i had available. The actual usable space above the garage is the full 22' x 24' because I built 4' knee walls to eliminate the loss of floor space that I would had due to the roof rafters. I also built a full shed dormer on one side to further improve the headroom and add some windows for good light. I was very concerned with the weight of the equipment in the studio. I wanted to avoid lally columns to support the center beam holding up the second floor structure. As such, before building it, I went to a structural engineer to have a LVL spec'ed to carry the load. He specified (4) 1-3/4" x 18" LVL, glued and bolted together to support the load. After I finished framing the building, I was simply not happy with the stiffness of the floor. Sometimes it is less about handling the load, and more about having a nice stiff floor system. As a result, I ended up putting in a cement-filled steel lally column to stiffen things up. (Keith actually mentions doing this in his prior post). Now my floor is rock solid, and I am a happy camper. At this point I am just past the drywall stage and am getting ready to do the finish work, floors, etc.. As I said, I will look to post pics soon. My two cents on whether to build it above the garage or in the basement......until 4 years ago I had my studio in the attic of my old house for a number of years.......and although it was not without its quirks, it was a very good environment. I then built a 600 sq. ft. full-blown studio in the basement of my new home, and to be honest, I just haven't been happy there. For me....I have to come out from underground! But I think much of that is a preference thing.

Alright! Good to see some other "top of the the shop" projects. I am in the planning stage of my project right now, still waiting for my copy of Rod's book to arrive. I look forward to seeing how you tackle the isolation issues(if you don't decide to go subterranean), as i will be going down a similar road eventually. Good luck with your build!

thanks to sharward, mickdoo and g-raj for piping in. mickdoo- please give details, pics, and drawings!!!!!!!!! I have some very major decisions to make that have major consequenses! All advice is appreciated. I'd like to see what others with an elevated wooden deck are going through. thanks to all

Whether basement or above ground, ventilation and natural light are going to be issues, regardless. Windows are notorious sound leakers (weakest link in your isolation chain), and you'll need mechanical ventilation in either environment. I would not consider these criteria in your basement vs. bonus room decision. g-raj, do you have your own project thread going yet?

Yes, sharward, i have a thread in the design forum entitled "Out with the mother-in-law, in with the studio" which is documenting my confusion and indecision.

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I made some measurements to use as a baseline. Pretty crude stuff, but here it is... Radio Shack digital sound level meter. C weighting (32 - 10k Hz) Fast response All readings below are peaks while the same song was playing. (Cheap Trick's "Come On Come On Come On" off their new album, "Rockford", their best since Budakon!) The neighbor's reading were taken from their driveways... 10' from their front door. If the room above the garage was finished using standard construction techniques like the rest of my house, I guess it might read about the same as the Bedroom 3 readings. The room above the garage readings are louder, I'm guessing, becase there is no inner drywall or insulation above the garage, yet. Sounds coming from my basement are slightly quieter to my neighbors.

What is the proper way to address the lack of a sealed leaf in my roof area? I have soffit and a ridge vent that are not sealed. I have read several postings about the infamous 3 leaf design to help this situation, but I can't find a diagram in this forum. I can't picture it from the postings. I haven't found it in Rod's book. Does anyone have a diagram of the proper way to deal with this? Mickdoo- how are you dealing with that?

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I'm considering using double wall construction for the front, back and knee walls. Although I don't know if that is a little overkill, since I'll have drywall on RC-1 right beside it, and a big window on the front facing my neighbors. I will probably have to use drywall on RC for the angled side walls and ceiling due to weight issues. I have a plan for a third leaf (since my outer leaf is not sealed), but it is intricate and would be very hard to describe here. If I build it, I will take pictures. I'll break out the sound level meter and do another test at my neighbors' houses at that point and see if it's too loud. If I still need more sound isolation, I can use Green Glue on the floor and walls and add another layer of OSB (floors) and drywall (walls). If I still need more isolation after that, I can tear out the drywall in the garage ceiling and decouple that ceiling from the floor above. Is it a waste of time/money to have double walls right beside drywall on RC-1 (and a window)????

You're window is your weakest point, the ceiling limitation is the second weakest point but can't be changed. Going double wall in the side walls really won't help much. I'd go with a double layer on RC and green glue as per this drawing. cheers john

John Sayers wrote:

You're window is your weakest point, the ceiling limitation is the second weakest point but can't be changed. Going double wall in the side walls really won't help much. I'd go with a double layer on RC and green glue as per this drawing. cheers john

That has been my debate too in my "above the garage" project. Double walls seem to be a lot of work that would be "un-done" with the floor and ceiling area. Thanks.

John- Thanks for the help! The window is large. I plan to make a window plug to be used for when I get loud. ...either that or some special acoustically insulated interior shutters. I have some soffit vents that may be blocked if I get too close to the bottom corners with drywall. What if I would build the infamous third leaf out of drywall to be used near the open vents in the three corners, like in the diagram below???

more like this IMO. cheers john

What do I put on the short knee walls, to make that a "trap"? Or does something, like fiberglass or Roxul, go in that space?

Hi Britune - check out my build thread, page 9 about a third of the way down. Something like these perhaps? Hope this helps mate, Regards and good luck with your project, :wink: Lou. 8)

What would cover the knee walls inside the room for these bass traps to function? Drywall? Cloth? Does this keep sound from escaping the room? Or is it a room treatment for a better sounding room?

Hopefully not stepping on JS's toes, but I believe the intent is to maximize your room volume, and since that space is not functional, it can function as acoustical trapping. It's just making the most of what you got. The front of the trap can be covered with any type of fabric (fire-treated of course) (functional as broadband absorber) or could be covered with wood slats (such as a slot resonator, to keep a bit of high end, absorb lower freq). Once you seal the back side of the trap (with drywall or mdf), then the entire thing can be filled with insulation (such as a super chunk), or lined with insulation, as well as between studs on the knee wall. Rockwool is prob your best (cheapest) option. I got mine from SPI in pitts. They deliver down here couple times a week. Though, when I ordered, they only had some dense 8lb stuff... may want to special order some 3lb or 6lb stuff. (They also had some JM814 (Its an OC703 equivelant). kevin

If it means I would have fabric knee walls, I don't think I can do it. One of the things I agreed to with my wife was to make a room that would be normal enough to re-sell to others. I plan on living here forever, but you never know what could happen job-wise in your professional career. I think I'll have to put drywall for the knee walls and use room treatment on that. But I appreciate the help and ideas!

not to be argumentitive, but you could always drywall the knee wall if you need to sell at a later date... or again, you could cover with wood slats (which more or less would look like panelling.) kevin

I'm getting closer to ordering materials... so I want to finalze my design. Don't know if I'm overthinking the "third leaf so I have two sealed leaves" thing... but what about the design in the picture? Would lining between the studs with MDF help seal the outer leaf???? This would allow me to keep normal looking drywall in the room in case I need to sell the house later. I think this would give me two sealed leaves everywhere. Am I on the right track? Or is this a waste??