Studio Design for a 28' by 22' garage

Im really sorry Ive been so confusing. I seem to confuse whether I keep is simple or include alot of detail. Some of these principles, I understand easily and quite well, but it seems theres always a dark side to all ideas, little details that make it work or dont, and my inexperience blinds me to alot of basic possibilities. Its like I get the theory, but when Ive got to dig deaper to complete the idea, my lack of construction knowledge stumps me. Ill spend a week on an idea that gets killed with the raising of one missed point. And all this stuff interrelates, so you kinda have to have a handle on the whole picture, or you go down too many dead end roads. Like your AC plan could totally change your optimum floor plan. Maybe Its time for another consultation with you Steve, thats seemed much clearer for both of us. Im really ready to begin. Im not trying to be impatient, but Ive got to get back to work and put this behind me. My concerns right now are... *Making sure my plans are safe and functionable *Validating any part of the plan thats not fully understood, planned or ironed out. At least enough that I wont want to change things later. *Getting some decent material lists, so I can start scouring rescources for deals. *Possibly finding some good "shortcuts" or at least weeding out any impractical ideas from plan. The first and foremost concern is the strength to hold the drywall. I want this to work, I just dont understand my boundries of whats enough or not enough. *Is the sistering of rafters better than going 12" instead of doubled 24"? (I may make "beef up easier" but if its stronger at 12" than Id rather cut the drywall more. *Is the sistering or adding rafters and collarties at 12" necessary throughout the garage or only where the ceiling will be hung? *If 12" is better, than I cant help but think or at least try to see if 2x6 rafters will work here fine, too. Im OK with 2x8, I just want to check because it would be better for height. If its impossible, then 2x8 it is. If we can determine my safety limitations, the next major concern is The UnVented Attic: Im really nervous about this part. I dont fully understand the whole vapor thing really. The applications I read about dont exactly apply to my situation. I afraid to do it wrong, and everytime my plan changes I question wether its necessary. I can see two scenerios in my head 1)THE SEALED UNVENTED STRUCTURE- Have an unvented structure as "leaf 2" except the upper front HVAC area, (as described in http://www.johnlsayers.com/phpBB2/viewt ... c&start=90 a little past the middle of the page.) My questions are A: Do I vent the HVAC area like a little attic? Or do I seal it? *Do I have some sort of controlable, sealable ceiling fan? Is this now the "attic" and what does it mean to the rest of the unvented structure? *Does this area need to be conditioned? *Does the sealed unvented garage need to be conditioned? Its not just a conditioned attic, its the airspace between inner and outer walls and room ceilings and the roof. Ive read it should be conditioned in an unvented structure, but I also remember Steve telling me it was not necessary 2)THE HALFWAY VENTED ATTIC If I dont seperate the HVAC space and the space above the Control Room and Iso by sealing, I could make a vented attic halfway across the first half of my garage. Over the Live Room will be unvented and sealed off. *This makes me think I can have an attic properly and still have the roof above the hanging ceiling of the room be unvented and therefore a proper 2nd leaf. Will this work? *Does this make the roof above the front part(CR,ISO, and HVAC area) of the garage a proper attic *Do I need a second leaf over these parts now?If so , how? *Do I condition the unvented part above the live room ceiling? Can you see how this is confusing? The only reason Im wanting the unvented attic is to make the roof a second leaf and get the room height. The question is, do I have to make this structure an unvented structure all the way, or just have less "vented attic". Is half the garage enough attic? If it is I dont need to worry so much about the proper ventilation and humidity, and Im waisting my time. If its all or nothing, then how do I do it right? If its better unventilated, do I ventilate the HVAC area? Is THIS enough attic? Do I condition the garage space? Do I condition the HVAC room as well? Id really like to resolve this, if I could, so I dont keep working on a plan thats fundamentaly bad or not neccessary, as well as I dont want to do something to let my garage rot. My inexperience sometimes makes me avoid things I think are too hard, and really there no big deal. I also sometimes spend time figuring out something that can be done way easier. This sends me in paths that are not necessary and distract me from my real concerns. I mean if theres a way to use the roof as a second leaf and still have a normal attic, then Ive been wastin all this energy trying to work around the theory of a unvented attic. These seem to me the spots I can really do some damage, waste time, and possibly even have an accident. After that evrything is either me checking on a "shortcut"(like doing the CR in 2x4 framing, possibly a single walled CR sharing an adjacent wal with the already single walled ISO booth.) or general confusion, misunderstanding, or searching for totally new view pionts. Id like to make it safe, and constructively sound first, but Ive gotta to evaluate the true necesity of each step to not overkill and end up with a half finished studio because I ran out of cash doing it "right".

Mike, thoroughly read this document from the Building Science Corporation -- especially Page 6 that covers unvented attics in climates such as yours and mine. I'm totally engrossed in that document right now! 8) And be sure not to miss the Unvented Roof Summary Article linked from page 7. Note to others: The document applies to climate conditions that are somewhat unique to the region in which Mike and I live.

Yeah, those are the ones I've been trying to wrap my fuzzy head around too - just when I think I've got it, pffffft!!?! - hopefully soon... Steve

Im not through it, but these are great, Keith. We started with something just like it, but it was mostly discussing vegas and arizona. Ive noticed two things though 1) On page 5 of Keiths first link, Figure 15 was referred to when talking about unvented AC basic examplethis AC setup is pretty much what I was thinking...Seems simple enough where I might be able to do this instead of keiths way of HVAC(expensive) 2)The roof assembly has that layer of rigid insulation and another sheathing (vapro barrier, right?), and then the ply wood on down. It seems I need to find an acceptable method not using that, or do that.(expensive right?) Ill keep reading...Oh is sheathing plywood? Oh well at the bottom of page 6 is figure 17. I think that what I got. Yeah!? Is that rigid insulation on the wall inbetween the studs?

I had a conversation with my cotractor today. He feels a bit funny hanging 3 layers off the sistered rafters and extra collar ties,especially around the collar ties. It kinda surprised me(due to my inexperience), but he suggested we do a arched ceiling supported by the live room, under the rafters and collar ties. I wouldnt have thought of that as easier, but hes concerned with sistering rafters and because of irregularities, they might be really hard to fit. That makes sense to me, Ive even thought of that before. The drawbacks are lower ceiling and the highest part wont remain for a while like my old plan. Positives are less wood, no clips, more air space, probably safer?, easier?, definitly cheaper, and thats all I can think of. Heres a pic, any Ideas?, safer?,easier?, better? thanx, mike

Mike, I'm not clear on what such a proposed plan would do to your iso. Let's see a cutaway illustration of your leaves, starting from the sky through the roof shingles down to the air inside the live room. If time's an issue, then maybe a thorough line-by-line inventory of the objects from top to bottom (including air).

I think I can explain it, without new drawings. Its just a vaulted ceiling lying under the garage ceiling. It will be totally decoupled, no use for clips, just losin space. It will suported by the live room walls, just ,ike the other rooms, only vaulted. you got that, or do I got to stick my head in Illustrator again?

So, we're talking two leaves then -- original roof is outer leaf, and new vaulted ceilings are inner leaf... Right? Are you going to beef up your ceiling at all? I know you got a "permission slip" not to beef up your outer leaf walls, since the stucco is wavy and thick and you're going to make up for the difference on your inner leaf walls... But I don't recall what (if anything) was said about your roof situation. :roll: I think I can follow a written description, but I'm nearly certain that Steve will be able to participate more if there's a good cutaway view showing all the ingredients of your delicious acoustical sandwiches. Hold the mayo, please. :P --Keith :mrgreen:

Ok heres some diagrams that i hope are clear enough. Im not exactly sure of the fine framing details, so forgive any errors. Im hoping this will just give yall a picture. First is my garage, with the live room and you can see the garage joists(light brown) and collar ties(dark brown). Thats just for a mental picture Next is the same diagram with the Live Room joists. Notice they are 24" apart but offset by 12" from the garage rafters. No toucho. And youll see the ridge beam in the middle. Here is a front view of just the room that will be built... The front and back wall will support the ridge beam, I guess like a "gable truss"(if thats right terms) Is that good enough to get a picture? I had an idea(pretty sure its wrong though). The front view I first showed , with garage roof and live room ceiling looks really close to a scissor truss. I know this is probably wrong, but can I make a scissor truss out of rafters that connect at a ridge board. It looks right, but when I read about trusses, it seems like thay must be assembled before hand, It would be cool though if it were possible..

I'm still not getting my question answered, Mike. I think a view something like this would be helpful for me, Steve, and everyone else. This example is from my plans -- it's a cutaway view of my ceiling structures. It doesn't count the roof because the roof isn't really a big part of my overall isolation plan. I believe it is in your case, so you'd need to show that as well. Something else my example illustration is missing are measurements -- those would be good to have as well. Hope that helps... --Keith :mrgreen:

Ahhhh... :?

Well Ive talked to my contractor, and he says he has a room he built at his house thats built like this and its 40' wide. The ridgeboard will be secured by the walls perpindicular to the ridge board. Remember, although this method would save me money, the reason he says is that since the building is old and has shifted, hes worried matching rafters would be very difficult. That with the money savings makes me want to give up the space and live with this. Heres your cutout, keith. Note: Im planning to add drywall between rafters, as garage roof beefup, but I forgot to include in photo.

So the outer leaf roof will consist of two layers of asphault shingles and paper, plus 1/2" plywood? Isn't that really wimpy? :? :roll: That's been my point of all this, Mike. Bottom line, I'm concerned your roof won't keep up with your walls. You have an inch to an inch and a half of stucco on our outer leaf walls, right? I'm guessing your roof is roughly half that in terms of mass. Are you willing to accept the possibility that the roof wil be the weak link, and/or add one more layer to your inner leaf (walls and ceiling)? --Keith :mrgreen:

oops Ive been so concerned with basic design, I forgot to mention beef up. And yes I still plan to beef up ceiling, and still possibly the walls of the new addition cause theyre flat. The new edition walls are also(in to out)... studs---paper---rigid foam insul---stucco. Mot as beefy as my old stucco, but its also in fronmt of my CR, but its easy so I probably will. Hey doesnt it make it a third leaf if I add drywall to new edition walls between studs. Isnt insulation count as air so Id have mass(drywall) air(rigid insul) mass(stucco)? Thats it 4 now.

styrofoam insulation is closed cell, so it does not count as airspace. it is mass (although very wimpy mass).

Right. If you can't blow air through it, it isn't air, so therefore it's mass (albeit utterly wimpy mass).

A little side note here. I need to seal the space between the roof sheathing and the rafter sitting on the outer wall top plate. On the east wall. there are some 2x6 fillers filling this gap on the inside edge of the wall. I am assuming, except for gaps that had vents, these were on evry gap, but theres only a few remaining. Since the top plate is 3.5 inches wide and the 2x6 is 1.5 inches thick, them there would be a 2 inch air gap to a end board runnig along side the outside, the rain gutter is attached to that. This end board is not sealed and only a 1/2" thick. My question is...Do I A) caulk these existing 2x6 fillers and and do the same with new ones where they are not? B)The same thing but remove the old ones and replae? c)Take them out and put a 2x4 all the way back to that end board, caulked of course, and caulk a seal between the 2x4 filler and the end board? The west wall is the same but there are no 2x6 fillers, possibly because the roof hangs over the wall to form an eave on the outside where the east wall ends at the end of the wall. I have 2x4 fillers more like I explained in answer C. Then every 3 theres a vent instead of the 2x4 filler. Steve explaned answer C to me on the phone. Stating that I should carefully inspect old one and if they seem like a solid fit caulk and put new ones in vent spaces. He also said to bevel edge of 2x4 to match slope of roof if necessary. If old ones are not beveled, and not tight, again replace. I just dont know if I noticed the difference between east and west walls, so Im a little unclear on what to do. The easiest route would be the 2x6 on the inside edge, because theres like 5 ir six left. I could cock those and add some more alot easier than to replace all. pic 1 east wall 1 space with 2x6 one space without pic 2 west wall one vent and one existing 2x4 filler thanx mike

Whats harder to hold up for rafters, layers on top of rafters or layers hanging off of rafters?

It's the same weight; so any given rafter size and length and spacing would hold the same amount of weight regardless of which side it's placed on... Steve

OK Ive been gone a little while, but Im back and I think i want to start some beef up and sealing now. First step is acoustic sealant. Ive read several threads now and from what I gather the USG seems to be the best to me. Keith hows that OSI Pro-Series SC-175™ Acoustical Sound Sealant working for you? Ive got to drive so Ive got to decide where and go. Ive got a new rework of the ceiling plan Ill try to post later thnx mike

mikeklooster wrote:

Keith hows that OSI Pro-Series SC-175™ Acoustical Sound Sealant working for you?

I have nothing to compare it to, but from my perspective it's working great. I've gone through seven 28-ounce tubes so far. I think it's more expensive than the Sheetrock brand stuff that Dan got his hands on -- $4.081 plus tax plus 0.25% fuel charge. If you end up getting that at AMS here in Sacramento during the week, you'll have to give me a call beforehand -- I work a couple of miles away from there. --Keith :mrgreen:

cool i think Ive decided on USG. Any clue to how much or how to calculate?

AlexT used six cases for his project, so I bought five, knowing that I could get more easily (assuming it's in stock when/if the need arises). I've used 7 out of 60 tubes so far.

OK. Been revising the live room ceiling plan, and I think I might even be able to keep it simple. Here goes..(live room is 20'x15'east side and 10'6"west side 1)Temporarily remove collar ties in live room area. 2)Build new live room rafters so that the ridge board isjust under, but not touching the garage ridge board. The 2x8 rafters are ofset the garage rafters so the bottoms can overlap a little, staggered I guess. 3)Replace missing garage collar ties with steel strap collar ties. Dont know official details but lets assume it rivals strength of old collar ties. 4)collar tie(assuming 2x8) the live room rafters so that their bottoms sit below the bottoms of the steel straps. Remeber the rafters are offset between garage and live room. This seems logical to me, and I get a whole lotta height. I think you were telling me(steve) I needed to collar tie live room. This does that, uses less wood and work sistering, no clips to buy, totally decoupled. Whatcha think?

Just might work; you'd bear the new inner rafters on inner walls, right? Steve