Small Room in Portland, Oregon

Hi gang. First time poster here, although I've been reading as a lurker off and on for a couple years now in the hopes of perhaps one day starting a build of my own. Well, that day has come. It isn't ideal by any stretch, but then again, when is it ever? I have rented a house, and it has a small unattached shed in the back yard. Interior dimensions are approx. 12' x 16' with a pitched roof starting at approx. 7'-2" with the apex at approx. 10'-6". One door (32" opening), no windows. Construction is wood framing on a concrete slab. Studs are 24" oc. It is already wired for power, on a separate 20 amp drop from the house main breaker. The main purpose of this room will be to record and mix my own material, including drums. Figure 100-110db inside when drums are playing, but I try to keep my playback levels around 80-85db. Obviously, because of the (lack of) size, I'm looking at a one room solution. Some isolation from the outside world is necessary (there are 2-lanes of moderate traffic approx. 60' away), although because it is free-standing, and there is a good 20' between my outside wall and the neighbor's (see pics), I don't think I need to shoot for an STC of "baby sleeping in the next room". I would think that something in the 30-40db range would work fine for me (although more is of course better if feasible). I'm willing to work around the occasional bus if I have too. As far as budget and time frame... well, they don't exist, really. So, I'd like the whole thing done by Monday morning, and to come in at around 50 dollars. Okay, fantasy over. The budget will work on the basis that two to four hundred dollars should hopefully buy me enough work to keep me busy for a couple weeks until I can afford another 2 or 3 hundred. The thing is, because this is a rental property, I don't really want to spend a huge amount of money since I have no idea how long I will actually be here. The plan is to be here at least 2-4 years at this point (quite possibly longer), but of course I've never met anyone with a working crystal ball who can see the future with any reliability. That said, I'm willing to do and spend what it takes to have a usable space. My initial thinking is as follows: 1) Tear down existing drywall 2) Beef up the stud wells with MDF ( need some help here; how does one do this exactly. Should the MDF be attached directly to the outside leaf, or toe-nailed to the studs?). Caulk and seal. 3) Pink fluffy stuff in the stud wells. 4) Frame a second door on the inside to have an airlock of sorts (2 metal doors, back to back with a small gap between). 4) Hat channel 5) 2 layers of drywall on the inside, caulked and sealed. This plan leaves the room completely rectangular so that I can leave a space that will be again usable as intended (garden shed) when/if I leave. Interior acoustic treatments will be more problematic this way I know, but any superchunks and traps and slat absorbers etc. that I build will be able to move with me. I have read (and am even beginning to understand parts of) Rod Gervais's excellent book (2nd edition), but still am feeling like a little knowledge is a dangerous thing. I need some advice about my plan of action. Does it seem like a good starting point? Also, I need some help thinking about ventilation. I think I'd like to somehow use a window unit mounted in a box outside, and duct the air into the space. At only approx. 175 sq. ft. I don't need a huge amount of airflow, but something will certainly be necessary. I'm also concerned about how much weight the roof will actually bear. If you look at the pics, it seems that the rafters are just sort of toed together up there with no beam, and I'm a bit leery of hanging 2 layers of drywall from that. I could cross-brace the rafters and build an interior ceiling on top of that, but that would drop my ceiling height to 7' or so. Perhaps I could do the cross half-way up the rafters, and have angled sides before the flat ceiling in an attempt to keep most of the weight on the walls... ? I am unsure how to approach this, but I suspect I'll need to have a structural engineer come and look before doing anything. Anyway, please have a look and let me know your thoughts. Your input will be greatly appreciated. This forum is an invaluable source of information and help. Thank you, - Devin

welcome! you will need to beef up the roof framing in order to support the additional mass - if drywall is cheaper than MDF then use that. the new mass goes on the inside of the exterior sheathing - on the roof - you want to consider the ventilation - while it's a shed now, you're turning it into an habitable space so you should expect a difference in building codes to apply. use RC-1/RC-2 on the inside to decouple the new inner drywall layers from the framing. a second set of doors. building an isolation chamber external to the shed to house the AC unit and then appropriate entry into the room to allow air exchange. on the sealing - there are several other threads on shed conversion and the issues around vapor barriers etc which you should research.

Hi Glenn, Thanks for your reply. So, I'm still researching and reading other threads for tidbits applicable to my situation. In the meantime however, I want to make sure that I'm understanding this bit properly: (leaving aside the roof framing for now, I understand that I'll need to have a structural engineer look and design better trussing to support extra mass up there) You're saying that I'll need to remove everything (including the outside leaf) down to the studs. Then for the outside leaf, Tyvek barrior wrap on the studs, then MDF (or drywall whichever is less expensive) on the studs, then siding on that. Does attaching the mass and siding through the Tyvek not compromise the barrior? Am I understanding this correctly? Thanks, - Devin

the tyvek should be on the outside of the sheathing between the siding and the sheathing. then you would add the mass to the inside of the sheathing. finally, if you have a situation with you need a moisture/vapor barrier/retarder then you would add that where appropriate - typically on the inside of the framing behind the inner isolation drywall. Brien may be along shortly to add more information. this link may be useful: http://www.oregon.gov/ENERGY/CONS/Codes ... 5.pdf?ga=t