Garage conversion - single studio/rehearsal room

Hi all! I thought I'd start a new thread with a more suitable heading. Previous posts can be read here: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8918 I've made a quick sketch to show the idea for the room. False resonator walls for broadband absorption, angled to prevent standing waves. Bass traps in corners, two of them enclosing the sound system speakers as well as the studio monitors. So when I'm using my portable home studio gear I can sit in front of the drums... Quite a compromise, but the main purpose for the room is rehearsing. More about that later, and probably in the studio design and acoustics sections... The other pictures show the current state of my garage. A few challenges here and there. I'm planning to do most of the construction over the summer and so I am eager to start. Some details will have to be worked out along the way (HVAC, electricity), even though it's not the best scenario. Before I do anything, though, I need to know about one thing that I've mentioned before: Below, there's a drawing of my outer walls - sectioned. Note the airspace behind the brick wall. I'm planning to attach OSB (between the studs) onto the existing gypsum boards, add 3 layers of gypsum and then build another single-leaved wall, creating airspace between the old and the new wall (see pic). A lot of you are familiar with this type of construction. BUT! Will the brickwall act as a third leaf even though it isn't airtight in itself (because of the venting holes in it)? Will I have to vent the brick wall even more? (Currently there are about 10 gaps, 1,5 x 7 cm wide.) Filling up the airspace is not an option, since the brick wall has to remain vented! Does anyone have any experience/knowledge of this? Thanks for reading! Cheers! /JOHAN

Johan, we live with the cards we're dealt...... the answer is "yes" this is a 3 leaf system.......... but also "so what" = because you can't do anything to change it. Adding all the weeps in the world won't change that (and by the way - it would bbe a bad idea to have them other than low on the wall where they are now) So beef up the existing wall with a much mass as you can - and then add your inside wall to complete everything. Rod

Damn. :( Thank you so much for the straight answer, though! It's just what I needed and I actually found it quite uplifting... Gonna get right to it now and start beefing! First up, I'll make some drawings of the whole thing. Soon. /J.

Today was my last day at work and now I've got five weeks of vacation ahead of me! :D Would be nice to get a lot of the construction done before work starts again... I wonder how far I'll get... I feel quite confident about the "beefing up"-process now so I'll start with that this weekend! I've posted some drawings of the walls below. Tomorrow is when I'm taking my first serious trip to the local home depot. Gonna load the wagon with OSB, glue, screws, wood (for cleats), caulk and backing rod. I can't remember having bought any of that stuff before in my life....! :shock: Well, nearly anyway! :roll: I'll be fine.... I hope. The caulk I'm planning to use, by the way, is an elastic acrylic caulk at about $3,40. ............... I'll start by glueing two OSB's together. I'll use the stuff that isn't too thick, to get the boards tightly together. The two fused OSB's will be set on the existing sill inside the stud bay, directly onto the wood, caulking the joint. Backing rod and caulk in the other three joints. OSB will be glued to existing dry wall on the rear side of the existing studs. Cleats will be screwed into the sides of the studs, screws slightly angled towards OSB. Then onto the next stud bay.... As for the dry wall, I'm still deciding between leaving the cleats in place (like Sharward did) or removing them once the OSB's are fastened, putting them back after all the dry walls are screwed into position...... So-long for now!

5 weeks off huh? Awwwwwww, you'll get it ALL finished in that time!! :lol: (Just kidding!) Seriously though, that's some GREAT time to get some serious work done and hopefully you will do just that. Will follow your progress. Many Blessings on the new studio!

:lol: Thanks! :lol: Good to have you come by here now and then! I'm very grateful! By the end of this day I'm hoping to have all the OSB's sawn into the right sizes. Tomorrow I'll start glueing. :?: Actually I'd need a comment on the double OSB-idea... It's intended to reinforce the plate where all the dry wall will be fastened (with screws and glue along the perimeter). But is it necessary? :? OSB isn't all that cheap, so I'm kinda thinking that the ones I have could be used for the ceiling beef-up instead......... only one layer for the walls...... Maybe someone has an opinon on this? By for now!

I came up with an idea for the walls: -Single layer of OSB with cleats. -Then two layers of ½" dry wall in between the cleats, screwed into OSB. The cleats are exactly 1" deep, so this should work out perfectly. -And finally two more layers of ½" dry wall with green glue sandwiched in between, screwed into and over the cleats. -Backing rod and caulk along the perimeter of each layer of gypsum. I think I'll have to pre-drill the holes for the last two sheets in order not to cleave the cleats. Now it's working time! /J.

That's similar to what I did: 1 layer of 15/32" (call it ½") OSB glued and cleated with 1½" deep wood pieces, 3 layers of ½" drywall screwed into the OSB, then one layer of 5/8" drywall with Green Glue on its back over the top of everything, with the screws of this final layer driven diagonally into the cleats and studs. I used many cases of acoustic sealant in this process, but I did not use backing rod :oops: because I wasn't aware of its benefits at the time... :roll: ...I'm not too worried about three-point caulk failures because there's so much "overkill" going on... --Keith :mrgreen:

That's similar to what I did

Yup! I was inspired by your idea to relieve the OSB of too much weight. :wink: Attaching two sheets of dry wall feels very safe, and that's the kind of feeling I like! The other two sheets are screwed into the cleat, after pre-drilling. Seems to work out very well. :?: About the caulking-thing...! Did you caulk for every single layer you added in the beef-up? I wonder if it would be such a shame to wait with the caulk until the final two sheets (in my case anyway)? Those sheets go over the joints of the previous two sheets like a lid (see pic) so maybe it would suffice to caulk the final two? (or three...?) Would be nice to speed up the beef-up, and to save some money...... :roll:

As i mentioned in the book - one perfect layer of caulk is all that's needed in a perfect world....... the remaining redundancy is just that -redundant......... so the final 2 layers would work........ Rod

Good times!! :D Caulking the final two layers seems logical to me. I thought it had to be in the book somewhere... couldn't remember reading about it, though. Well... my mistake! Thank you x100! /JOHAN

Ladys and gents! I'm back with some pics of my progress so far. It's going slower than I had expected, but then again I'm not really in a hurry - I just keep picturing how cool everything will look once it's all done, and I get frustrated by the fact that all I did in one lousy day was to get a couple of cleats and gypsum boards up... The place looks like crap right now. But it's the most promising piece of crap I ever saw! :) I want to save the insulaton I tore out of the old walls and ceiling 'cause it seems stupid to me to waste it only to buy new insulation a few weeks later. This puts up a challenge every now and then, since I don't have any other place to keep it than in the room where I'm working...... :roll: So this far, I've had to move it all back anf forth between different spots to be able to work on all the walls... But as I understand it, the greenish fluff is quite usable for sound isolation. It's the lighter, yellow stuff I'm not sure if I'll need... :?: It's been a week since I started the beef-up process and as you can see in the pics I've got two layers of dry wall up in virtually every stud bay. I've thought a lot about whether I should use green glue on the outer leaf or not. I know that one of my favorite bloggers here on the forum :roll: used green glue between the final two layers in his outer leaf, but I can't help thinking that maybe I'd be fine without that. I've got a gut-feeling (dunno if it's much of a gut, though, considering I've only been at this for a couple of months.... :oops: ) that the usual benefits of green glue don't apply to outer leaf beef-up the same way it does with inner leaf. You've got these massive studs going right through whereas with inner leaf, you've got a total barrier of dry wall where the green glue (supposedly) has a lot more area at it's disposal and can damp the entire leaf. :?: :?: :?: I've almost decided to leave the green glue out of the outer leaf and put my money on the inner leaf. Any thoughts? Next step will be beefing up the ceiling. My ceiling is, as previously shown, tilted and the highest point is in the middle of the room. I came up with two different ideas for beefing (see pic). The problem is that my ceiling joists are quite far apart from each other (38" oc) and I feel I will have to support the layers of beef not only around the edges but also in the middle somehow.... :?: I haven't solved this yet. I'm also deciding between doing a seperate ceiling supported by the new walls or putting up RC-2 on the existing ceiling joists and then 2 layers of 5/8" dry wall sandwiched with green glue. It's the load I'm worried about... STC-wise I feel I'd be ok with an RC-2 decoupled construction. Guess I'll have to consult a building official on this. That's it for now! Have a great day and thanx for reading! /J.

Hi. Just a quickie: I'm just about to start beefing up my ceiling now and I need to know a few things. Could someone help? :?: 1). As mentioned, the material facing the inside of my garage is solid wood T&G. I'm considering nailing the gypsumboards directly onto it. Any reason not to? What would be a good way of attaching my 3 layers of 1/2" dry wall between joists that are 38" apart? (Any risk of the dry wall bulging in the middle of the joist bay?) :?: 2). There are nails protruding through the T&G (see pic). Must I remove them or could I just as well use them to hold the first layer of dry wall up? (I'm gonna have to put nails through the gypsum anyway....) :?: 3). The design below (ceiling construction3) shows how I would prefer to do the ceiling. Does it seem like an all too heavy load? Joists are 38" oc, 2x8" wide, resting on brick wall on both sides (the room is just over 16 feet across). I will replace the cleats with RC-2. (No cross-bridging in this design.) Cheers! /J.

Johan wrote:

:?: 1). As mentioned, the material facing the inside of my garage is solid wood T&G. I'm considering nailing the gypsumboards directly onto it. Any reason not to? What would be a good way of attaching my 3 layers of 1/2" dry wall between joists that are 38" apart? (Any risk of the dry wall bulging in the middle of the joist bay?)

WIth that sort of rafter spacing - my best bet is that the wood is at least 2" (nominal) thick - screw right into it it - after verifying that what Iguess to be the case is true of course..

:?: 2). There are nails protruding through the T&G (see pic). Must I remove them or could I just as well use them to hold the first layer of dry wall up? (I'm gonna have to put nails through the gypsum anyway....)

I would put up a thin layer of rigid isulation between the old and new to deal with the nails.

:?: 3). The design below (ceiling construction3) shows how I would prefer to do the ceiling. Does it seem like an all too heavy load? Joists are 38" oc, 2x8" wide, resting on brick wall on both sides (the room is just over 16 feet across). I will replace the cleats with RC-2. (No cross-bridging in this design.)

I have no comfort level with this at all - I would seriously recommend that you double check this with a structural engineer - ( a building offical should actually balk at answering the question - it is forbidden by code for them to do so.). Rod

rod gervais wrote:

WIth that sort of rafter spacing - my best bet is that the wood is at least 2" (nominal) thick - screw right into it it - after verifying that what Iguess to be the case is true of course..

Afraid not... I went and measured it, and it's only 5/8". Do you think the 3 layers of 1/2" gypsum will stay up long enough for me to cleat them and thus hold them in place? (Using 1" screws for the first layer, then 1 1/4" for the second, then 1 5/8" for the third.)

I would put up a thin layer of rigid isulation between the old and new to deal with the nails.

Does this mean that even if I clip the tips off, the nails will interfere with isolation? Or is putting up rigid insulation simply an alternative to clipping?

I have no comfort level with this at all - I would seriously recommend that you double check this with a structural engineer - ( a building offical should actually balk at answering the question - it is forbidden by code for them to do so.).

Ok. Thanks for clearing that up! Sincerely, /J.

Johan wrote:

rod gervais wrote:

WIth that sort of rafter spacing - my best bet is that the wood is at least 2" (nominal) thick - screw right into it it - after verifying that what Iguess to be the case is true of course..

Afraid not... I went and measured it, and it's only 5/8". Do you think the 3 layers of 1/2" gypsum will stay up long enough for me to cleat them and thus hold them in place? (Using 1" screws for the first layer, then 1 1/4" for the second, then 1 5/8" for the third.)

Now I have even LESS of a comfort level - that spacing for 5/8" board isn't even close to meeting the 40psf live load requirements for a roof.

rod gervais wrote:

I would put up a thin layer of rigid isulation between the old and new to deal with the nails.

Does this mean that even if I clip the tips off, the nails will interfere with isolation? Or is putting up rigid insulation simply an alternative to clipping?

NEVER EVER cut off the nail ends - the free nail penetrating the board is a part of the holding ability - if you clip them you take the chance of them letting go.

rod gervais wrote:

I have no comfort level with this at all - I would seriously recommend that you double check this with a structural engineer - ( a building offical should actually balk at answering the question - it is forbidden by code for them to do so.).

Ok. Thanks for clearing that up!

Seriously - it will be the best couple of hundred dollars you spend......... Rod

Urgh... This doesn't seem to be going my way at all.... :(

rod gervais wrote:

Now I have even LESS of a comfort level - that spacing for 5/8" board isn't even close to meeting the 40psf live load requirements for a roof.

I don't quite follow... I might be a complete fool now, but... What live load will there be on a roof? I've just recently learned about live and dead loads from your book and it seems to me the live load on a roof will be the occasional chimney-sweep (although the chimney isn't close to where I'm building the studio) or something hung from the ceiling, i.e. lamps, absorbers...

NEVER EVER cut off the nail ends - the free nail penetrating the board is a part of the holding ability - if you clip them you take the chance of them letting go.

That is some valuable info! Great! Will go for the rigid insulation then! .....That is, when I have a working plan for the construction. :evil: I will definitely consult a structural engineer. Thanks again! /J.