Trying to beef up outer leaf, 2 questions

[Nathan]

Hi,

This is my first post though I have been reading quite a bit on this forum. Thanks for all of this great information.

I just purchased a house with a separate 20x24x8 (inside dimensions) garage in the back yard. I'm planning on building one large room for tracking, mixing and occasional band rehearsal in there.

I want some isolation from the outside; I don't have a specific goal here; basically whatever I can get using separate frames, insulation between them and two layers of drywall on the outside of each. Basically that is what I can afford in $ + space, so I'm forced to live with the results either way, if I I have to buy my neighbors a little less beer I'll be happy.

The garage is built on a concrete slab, the two 24' walls are constructed from 2x4s spaced at 16", and the two 20' walls are constructed from 2x4s spaced at 24". On top of that are two 2x4s laying flat ("cap?") and then the roof trusses. These are pre fab type with metal brackets stamped into the corners. The bottom of these of these is a 2x6 which the current particle board ceiling sits on.

I have torn everything out of the garage back to the frame, and am about to remove the window and garage door and frame/add siding to match the rest of the building.

My plan is to add mass to the outer leaf using drywall attached inside between the studs, before constructing a separate frame for the inner leaf of the wall. The outer leaf currently consists of one layer of wood siding.

There are two areas that have me confused. I understand I want a continuous mass for this outer leaf, but I'm having trouble figuring out the best way to join the ceiling to the walls, and also what to do about the corners.

So question #1 is how do I connect drywall from the existing ceiling joists (which I plan on adding drywall on top of so I can tuck the new joists in between them) to the walls so that it is a continuous mass?

I'm afraid of creating an airspace where I pass by the part of the roof under where my new ceiling drywall will be.

Here is a picture (which I hope is clear enough).
<img src=http://www.solisearch.net/ims/pic.php?u ... k&i=158772>

My second question is regarding the corners where the studs meet. It seems there is an airspace in the corner. Do I just try to caulk inside them or do I pull out one of the studs and add drywall or mud?

Here is a picture of where I'm talking about. Maybe it is solid and I'm just not seeing it right.

<img src=http://www.solisearch.net/ims/pic.php?u ... k&i=158773>
Sorry if these questions have been answered somewhere else already; I've done searches and can't seem to figure out the best way to approach this.

[knightfly]

Nathan, your pix don't show up; if you convert them to jpg and size them no wider than 750 or 800 pixels, you can post them directly here. Max file size is 150k per pic.

Just click the Browse button below the text window while posting; navigate to the pic on your hard drive, and if more than one pic you then click the Add Attachment button, then browse again, then Add Attachment; you'll be limited to three per post (I think) ... Steve

[sharward]

Welcome, Nathan. Very nice introductory post and photos -- you've definitely been doing your homework here!

I definitely see some similarities between your project and others here, namely mine, Dan Fitzpatrick's, and Mike Kloosters. Perhaps you've been lurking in our threads already.

• My project is probably less square footage than yours, but it's a one-room deal like yours.
  
  Dan's project is also one room and I think a little bigger than mine, and he's planning to convert his door to a wall -- but the door will remain visible on the outside.
  
  Mike's project is probably closer to your size, and similar in the sense that he's converting an unattached garage and has already gotten rid of his door.

We all debated long and hard about floating floors, and I believe we're all pretty much planning not to float.

Here are some initial thoughts:

• It's important that you set your goals and then determine what it will take to achieve them. You said, "I want some isolation from the outside," which leads me to think you don't want outside sounds getting in, but you mention "buying neighbors a little less beer," which leads me to think you're wanting to ensure that inside sounds don't get out. (Maybe it's both...?) Limiting yourself to two layers because you think that's all you can afford is, in my opinion, putting the cart before the horse. Set your goals and then make a price tag for it. If it's too rich for your blood, then see if there are ways you can be more economical without sacrificing results. In setting your goals, i.e., ideally defining the level of soundproofing you will need to achieve in before-and-after decibel measurements, you should determine what your local sound ordinances are. Learn them like the back of your hand. There's nothing worse than spending all your money on a solution that leaves you susceptible to being shut down by the sound police.
  
  Based on what you described, you'll be creating an attic in your garage. You'll need to allow for access, either through the ceiling or, perhaps, through a door on the side of the wall where it peaks. Check to see what code requires. I think Mike is planning to beef up his ceiling somehow and seal it up "cathedral style," which will supposedly eliminate his need to ventillate the attic (gap between his leaves). I'm skeptical about this and the details have yet to materialize. It would be worth staying tuned to his project very closely.
  
  You haven't talked about ventillation yet, which you're going to need... And definitely A/C down there in Arizona! Do you have plans for that yet?
  
  The first photo shows what appears to be plywood on the outer leaf... But you said "The outer leaf currently consists of one layer of wood siding." Is the wood siding attached to this plywood? You need to be as specific as possible about the existing construction. This will dictate how much, if at all, you will need to beef up your outer leaf, as well as any other preparations you'll need to make.
  
  The second photo shows what appears to be gypsum wallboard on the outer leaf. You said this is "separate" -- does that mean it's fully detached? What's on the other side of the gypsum wallboard areas? (Or am I misinterpreting the photo?) A top-view illustration of where the garage sits relative to the rest of the house, and where your property sits relative to neighbors, will be a big help here.

More pics, some drawings, and more info -- let's roll!

Welcome to the madness, Nathan!

--Keith

[Nathan]

Thanks for the response Keith.

I have checked out the three posts you mentioned; I have referenced yours quite a bit while trying to figure all of this out. I don't plan on floating the floors either.

As far as what goals I have; the number 1 goal is to keep as much ceiling height as I possibly can. Maybe I'm not understanding correctly, but my logic is this: if I want to have one large room, I'll need at least 2x6s on the inner frame ceiling to span the 20ft width. It seems like that is only going to hold 2 layers of drywall. If that is the case (maybe I need to calculate that more carefully) then there wouldn't be much point in a third layer on the walls. If I have to use 2x8s to do a third layer I'm going to have a really low ceiling once I install whatever acoustic treatment I need.

I do want to keep sound both out and in, however what I do 95% of the time isn't that loud. For the loud stuff, which will only be when I'm working on someone else's project, I will just schedule it for when no one is around (weekdays). I've had a really busy project studio for about 5 years and fortunately can choose which projects I take on. Mostly now it is just mixing/some overdubs or acoustic stuff. If I really want to track a nu-metal band, there are a few other places in town I can take them.

Ventilation for the Roof: I plan on putting some sort of attic fan up there, as well as some additional vents to keep is cooler as well as minimize the "three leaf effect"(don't know what I'm talking about, but that seems to be the answer...). This won't be accesible from inside.

Cooling: I am going to try one of the portable, roll around type ac/heater units. Evaporative cooling is really common out here, it is so dry that they work as well as AC units (except during August when it rains alot and gets humid), and there is no ducting to run. If that doesn't work I will probably use a mini-split.

As for the outer shell of the garage, the stuff that looks like gypsum is the backing of the siding as far as I can see, and the plywood is the back of the siding on the north side of the builing, which is slightly different from the three other walls. When I pull off the window and garage door to frame them in I will have a much better idea of exactly what is under there. It is definitely not more than a thin layer of siding and either plywood or that stuff that looks like gypsum (it feels sort of like masonite).

Here is a pic of the neighborhood and where my garage sits; the short walls of the garage are 20ft long, so that gives you an idea of the proximity to the neighbors.

<img src=http://www.solisearch.net/ims/pic.php?u ... k&i=159829>

[sharward]

. . . I have referenced yours quite a bit while trying to figure all of this out.

Ha! That cleared everything up for you, didn't it? NOT! Heh -- my rollercoaster thread is so confusing that sometimes I wish I could just toss it and start over! Just because people who actually do read through it start-to-finish (I pity them!) ride the same rollercoaster ride that I did/am!

Seriously, I hope you were able to get something out of it... If nothing other than not to waste your time on the dead ends I found myself facing.

. . . I'll need at least 2x6s on the inner frame ceiling to span the 20ft width. It seems like that is only going to hold 2 layers of drywall. . . maybe I need to calculate that more carefully . . .

Yes, you DO need to calculate that more carefully. Try using this Span Calculator for Joists & Rafters. Using Douglas Fir-Larch, you can't attach anything to a 2x6 on a 20 foot span, even on 12" centers! According to my quick calculations, and I'm the last person you want to be relying on for this stuff, you're looking at 2x8 on 12" or 16" centers, or 2x10 on 24" centers.

Do not be cavalier about this decision. Most of the decision points on your project will involve the level of soundproofing you will achieve. This one involves the level of not dying under collapse. Promise??

. . . If I have to use 2x8s to do a third layer I'm going to have a really low ceiling once I install whatever acoustic treatment I need.

I hear you. You have lots of company by those who are working on U.S. basement projects, or garage projects with 8' ceilings. (I'm lucky to have 10'+ to start with!)

I do want to keep sound both out and in, however what I do 95% of the time isn't that loud. For the loud stuff, which will only be when I'm working on someone else's project, I will just schedule it for when no one is around (weekdays).

Typically, noise ordinances are more forgiving during the week. However, be out of compliance at 2 PM on a Wednesday during someone's day off, or if someone's a graveyard shift worker (I used to be one, so I sympathize with those folks a lot -- even the moderator of this forum works graveyard shift a couple days per week), and you're screwed. Careful -- don't assume that just 'cuz it's midweek and midday that nobody cares how loud you get.

Also, even if everyone around you is cool, remember that cool people leave and not-so-cool people take their places. It happens all the time and is one of the reasons we decided to move last year!

. . . I plan on putting some sort of attic fan up there, as well as some additional vents to keep is cooler as well as minimize the "three leaf effect"(don't know what I'm talking about, but that seems to be the answer...). This won't be accesible from inside.

Will it be accessible at all? You'll need to be able to access it for servicing/repair... Pretty sure it's a code violation otherwise.

Cooling: I am going to try one of the portable, roll around type ac/heater units. Evaporative cooling is really common out here, it is so dry that they work as well as AC units (except during August when it rains alot and gets humid), and there is no ducting to run. If that doesn't work I will probably use a mini-split.

I planned on using a mini-split myself, but my building department said "no way" on that being the only ventillation option... Because it isn't ventillation at all. You need air moving in and out somehow. Also, if you're building habitable space (hint: you are), you need something permanent -- portable units won't pass the building department stink test.

Here is a pic of the neighborhood and where my garage sits; the short walls of the garage are 20ft long, so that gives you an idea of the proximity to the neighbors.

Cool -- you're lucky that you have a bit of a buffer zone around the garage before encountering peoples' living space. However, the "noise police" don't take their measurements from inside the victims' houses. They take them from the edge of your property line closest to the noise source.

I also had an opportunity a few weeks ago to take a bit of a "field trip" to the studio where Mike does a lot of his work in Stockton. Although they have pretty good soundproofing between control room and tracking room, there's virtually no soundproofing between tracking room and outdoors. Someone was laying down some drum tracks, and we found very little difference in noise levels between being right next to the building and walking to the far edge of the property (at least 100 feet away).

I raise all these things because I would hate to see you disappointed with the results. You seem to be OK with a "less than perfect" situation and appear to be willing to work with whatever limitations you're left with.

You haven't mentioned decibel levels yet, which will take all the guesswork out of the equation.

[Nathan]

Wow,

I had intended to calculate that before starting, I was making a guess based on a few other posts. Also, good point on making noise during the week, I hadn't considered that. I am on a pretty busy street; I will look into all of this but I don't think I will be making more noise than what is allowed.

I really can't live with ceilings under 7ft, I honestly don't understand how anyone can work in a room with <7ft ceilings, even close miked vocals sound strange to me in rooms like that.

I am curious about something though, I experienced this at may last place which was a big concrete block loft style house.

It seems that isolation "holes" seem to matter more depending on the direction they're facing.

I could be standing right next to the house, outside the front door with a loud band tracking and hear almost nothing. If I went to the back of the house, which had a wall of french doors, it was LOUD...

Since I now only have neighbors on three sides; would it make the most sense to put my doors/AC/vents facing the side with no neighbors? (ignoring the fact for a moment that the sound police might be sitting in that same direction).

Thanks for the comments; I'm starting my plans completely over now...for you guys hanging around here longer than I have...what is the average number of replies before someone decides that their plans are useless?

Maybe we could come up with a rating, sort of like STC, for this.

[Dan Fitzpatrick]

would it make the most sense to put my doors/AC/vents facing the side with no neighbors? (ignoring the fact for a moment that the sound police might be sitting in that same direction).

makes sense to me. i've got a middle aged lady neighbor whose bedroom (i think) is about 10 feet from my studio. for this reason i'm putting ventilation openings and my fire escape on the opposite side from her.

[sharward]

. . . what is the average number of replies before someone decides that their plans are useless?

I don't think we've ever evaluated it in terms of # of replies... But I'd say you're at #17 on the Stages of Soundproofing Enlightenment!

Hang in there, my friend!

--Keith

[Nathan]

So if that is logical, then my next question is will it make any sense to double frame my four walls, as I have been planning, but just leave the ceiling open and drywall up at the roof in between the rafters?

I totally understand wanting a complete, double framed shell totally surrounding me, but is there some compromise? Is the single leaf ceiling going to ruin my separate frames on the walls COMPLETELY or is is going to ruin their effectiveness only partially?

It seems like it would be worse above me, but since I'm not in a basement it won't be as much of a problem.

Also, with the trusses I have, I'm wondering is it safe to add 2 layers of drywall + some insulation to the underside of the roof sheathing to make the ceiling? Is there a "best" way to finish that ceiling?

[sharward]

I totally understand wanting a complete, double framed shell totally surrounding me, but is there some compromise? Is the single leaf ceiling going to ruin my separate frames on the walls COMPLETELY or is is going to ruin their effectiveness only partially?

I'm sorry to burst your bubble, but the answer is it is going to ruin your isolation if you do a "single leaf ceiling."

The acoustic engineer I am consulting with locally here in Sacramento said he has only lost one case in court as an expert witness, and it was the case of a drummer who built a "soundproof" room in his garage with big, beefy two-leaf walls, but he did not do anything to his ceiling, and a tremendous amount of noise leaked through his soffit vents to the outside world.

You cannot cut corners with the ceiling and expect good results.

There's quite a bit of talk on this forum of the "weakest link" effect -- in terms of isolation, if you have "great" walls and "great" doors and "great" floor with "terrible" ceiling, you have a "just slightly better than terrible" room.

Also, with the trusses I have, I'm wondering is it safe to add 2 layers of drywall + some insulation to the underside of the roof sheathing to make the ceiling? Is there a "best" way to finish that ceiling?

Welcome to my world! You are wise not to be making assumptions about the strength of your trusses.

For my project, I intend to pull drywall down off my trusses and install new 2x6 or 2x8 joists firmly attached to my outer leaf walls to hold my new outer leaf ceiling, which will take all the ceiling weight off the trusses and all the new outer leaf ceiling weight will be transferred to my outer leaf walls. Then my new inner leaf ceiling will hang on 2x6 joists that firmly attach to my inner leaf walls. I plan to have detailed illustrations of this in the coming days/weeks. You may want to consider the same.

[Nathan]

Thanks, I had already figured the ceiling would ruin most of the isolation I'd achieve with the double framed walls; I was just curious how much I was going to ruin it, like 100% or 75%. What are "soffit vents"? Just the ducts?


I think I'm starting to see a compromise between keeping some ceiling height and having some good isolation. I'm going to go to two rooms, one will be the control room w/ a couple layers of drywall + insulation against the roof, and I'll live with the crappy isolation to keep it open all the way up.

The other half of the will be the isolation room and will have horrible 7 foot or whatever height ceilings, I can practice loud in there and still track amps, etc. When I'm recording drums I'll just find a good time and track them in the control room so I can throw up some room mics.

I guess I should draw up a plan and post it so you guys can look at it.

[sharward]

What are "soffit vents"? Just the ducts?

Attic vents.

[Nathan]

So is there a best way you know of to finish the peaked ceiling that I'm going to leave open?

The area above my isolation room will just be finished so that it is an "outer leaf" ; with mass (drywall) added in between the trusses at the ceiling and insulation "hanging" on the inside of it?

My control room is going to be part of the air space; the isolation room will have mass inside, and all the control room walls and ceiling will just be single leaf with as much mass as I can safely add between the studs.

I'm assuming this is a valid way to vent the attic as well; it will be part of the air space in the control room which will end up with proper ventilation.

I'm also assuming that having all that air space between the inner leaf in the iso room and the outer leaf on the ceiling and the wall will be as good as having insulation between the frames where they are close together (other 3 sides of the room).

I hope my desciption is clear without a picture.

Also, how do I figure out if those trusses can hold 2 layers of 5/8 drywall between the ceiling rafters (think I'm referring to them correctly). Is there some sort of calculator for truss load?

[sharward]

You've asked some great questions to which I do not know the answers. Hopefully someone here can guide you.

You'll want to resize that photo though... It's currently 907 pixels wide.

[Nathan]

Resized...it's weird, the pixel dimensions I "save as" are always different than the size it ends up being here.

Here is a basic sketch of where I'm now heading:

The grey perimeter will be the existing walls, with 2 layers of drywall in between the studs with a 1/4" gap all all the way around. I'll caulk in there but still not sure if that can just be regular caulk or acoustical caulk- do I want it more rigid or more flexible here? Is this a different system than a drywall intersection??
Can't seem to find an answer for that.

The room on the left is my isolation room. It will be separately framed with a separate ceiling on the new walls, and get 2-3 layers of 5/8 drywall on the inside. On the 3 sides not facing the control room I will insulate. Above this space will be sort of a "loft" which opens into the room on the right.

I will drywall up in the loft ceiling as I mentioned before, and also lay insulation on top of the iso room ceiling under the trusses...I'm not planning on walking up there so not having a real floor isn't a problem- but maybe some perforated steel stapled to the original joists would be strong enough to hold a person while not creating another leaf?

The room on the right will be the control room. I'm guessing I won't be shooting myself in the foot by not insulating in here, because there will be so much airspace between the 4th isolation room wall and this room's walls. I will drywall in between studs like around the other room. This room will also have a door to the outside and whatever AC contraption I end up with will be mounted here.

I know this won't be very sound proof but normally the only noise in here will be my monitors and I can keep that under control MOST of the time...
any comments or obvious errors?