another garage conversion

I've been lurking and reading and asking some stupid questions here, while waiting all the paperworks&permits&etc for our house to be cleared. initially I was hoping to hire a company to do a design for me, but since it looks like it's going to take months to get this mess dealt ( that I'm not going to go into more deeply, our house has some unfinished paperwork hanging) and the cost of these "garage to homestudio"-designs would be roughly 2-5k€ I thought that I might as well try to see what I could come up by my own. and by my own I mean googling and asking more stupid questions here:) But I have this double car garage (picture attached) measuring 6.34mx6.34m (edit: inside measurements are 6.03x6.06m) that I would like convert into 2 rooms -Music production/mixing space (pictured green) I make mostly beats/electronic music and record Vocals and sometimes acoustic stuff. -and remaining space for my groupdiy/electronics/hobby stuff ideally this is space to temporarily drive my car in if needed. I think my first question is should I make my "music-side" of the garage as big as I can or split this "music side" to even smaller "control room" and mic booth?

I did think about the tracking vs control room type of room and personally will chose to do only a room since it will be used more as a music room to jam and I do not require too much critical listening since I don't like that much to mix my music. I will still want it to be "fairly neutral", but still lively. I chose the one room design as well for budget reason. It is one wall less to build, less material, less working time, etc... Good luck with your design.

djippy wrote:

I did think about the tracking vs control room type of room and personally will chose to do only a room since it will be used more as a music room to jam and I do not require too much critical listening since I don't like that much to mix my music. I will still want it to be "fairly neutral", but still lively. I chose the one room design as well for budget reason. It is one wall less to build, less material, less working time, etc... Good luck with your design.

Thanks! and good luck with your build! On the other hand I would like one "bigger"(as this really isnt a BIG) room. that would be symmetrical and had more distance to back wall, but If I would make a vocal booth then that would eat up the space from the front /back and my room might be even smaller and worse as a control room.. I know I could make gobos and other movable acoustic-thingies, but maybe I could build some sort of foldable mic booth that would have even just a little bit of isolation and enough absorption..and still get decent mix room/control.

Hi anodiverta, It would be best to not cut the garage exactly in half,as the garage is a square. You want to avoid any dimensions being multiples of another dimension (or within 5% of a multiple). You will have multiple strong axial modes around 54Hz. Increasing the width to around 3.6m would be a better starting point. I would definitely not split the music room any further. There is not enough space for a usable booth that won't sound like a cupboard. If you design your room to be relatively dry, then you can record your vocals fine in the room. You will find it difficult to mix in a lively room. If you want a multi purpose room you would be best off creating "variable acoustic" devices. This is a treatment device that opens/slides/swivels to reveal a different surface beneath. Using these all around the room can be used to "tune" the decay rate in the room to the desired amount for the use at the time. The simplest of these devices would probably be a ply wood panel screwed to a frame with the back filled with insulation and covered in fabric. Stand it up against a wall. When you want a dry room, turn it so the soft side is facing the room, when your want a lively sound, turn it so the ply wood is facing the room. Dan

sloooowly I'm getting on with this:) Allready built and vocal booth that has two functions: my mics are protected from the dust if I do something in garage and...well a vocal booth. still in the process of thinking what is the best way for my studioroom. Best way would be to tear the existing wall and make 2-leaf design, but since testing my current situation I get 100dB in vocal booth and 55-60dB outside the garage. It would be so much easier to build an floating room inside the garage than tearing current wall(+thinkin the moisture barriers etc.), but I'm afraid will this 3-leaf design make things worse? If my studio room would "breath" into the garage, the would this lower the 3-leaf effect/resonance frequency?

outer wall of this garage are made like "standard" in Finland is: that wood fiber board is something like homasote-board but this is much lighter (3kg/m3, I found that homasote is 6.5kg/m3)

Hi again anodivirta, Welcome back. Are you saying you already have built the room labelled "Isolation booth", and that's the vocal booth you mention, but you haven't started building the room labelled "Studio" yet? When it comes to room-within-a-room, you have to consider the mass and resonance of each leaf. Your garage outer wall, built the standard Finnish way is not caulked between the outer slats, and between the inner sheathing right? To use that as part of your outer leaf for a MAM wall, you would need to have a sealed outer leaf. You could take off the 12mm "chipboard" (do you mean OSB - Oriented Strand Board, as chipboard is not usually structurally rated) and remove the insulation, and then cut heavy plasterboard (gypsum drywall) into strips that you place in between the studs tight up against the back of the wood fibreboard. If you do this though, you may be required to provide cross "noggins" to prevent racking, as the "chipboard" sheathing may be structural. Then you build a second self-supporting inner frame room for your studio, and put the chipboard on this frame inside and another couple of layers of plasterboard. Filling out the cavity with low density insulation. The problem is, you aren't building a room within a room for the whole garage, which would mean you would have to have some way to keeping the inner sheathing, and moisture barrier intact on the walls around the rest of the garage and not coupling it to the inner "room" of your studio. This sounds quite difficult. In your situation, I would not touch the garage walls at all and build it triple leaf, simply increasing the amount of mass & airgap to counter any triple-leaf effect. Have you considered how you are going to ventilate (breathe) and dehumidify the completely sealed studio and isolation booth? HVAC or split air conditioning and active ventilation/heat recovery? Dan

Waka wrote:

Hi again anodivirta, Welcome back. Are you saying you already have built the room labelled "Isolation booth", and that's the vocal booth you mention, but you haven't started building the room labelled "Studio" yet? When it comes to room-within-a-room, you have to consider the mass and resonance of each leaf. Your garage outer wall, built the standard Finnish way is not caulked between the outer slats, and between the inner sheathing right? To use that as part of your outer leaf for a MAM wall, you would need to have a sealed outer leaf. You could take off the 12mm "chipboard" (do you mean OSB - Oriented Strand Board, as chipboard is not usually structurally rated) and remove the insulation, and then cut heavy plasterboard (gypsum drywall) into strips that you place in between the studs tight up against the back of the wood fibreboard. If you do this though, you may be required to provide cross "noggins" to prevent racking, as the "chipboard" sheathing may be structural. Then you build a second self-supporting inner frame room for your studio, and put the chipboard on this frame inside and another couple of layers of plasterboard. Filling out the cavity with low density insulation. The problem is, you aren't building a room within a room for the whole garage, which would mean you would have to have some way to keeping the inner sheathing, and moisture barrier intact on the walls around the rest of the garage and not coupling it to the inner "room" of your studio. This sounds quite difficult. In your situation, I would not touch the garage walls at all and build it triple leaf, simply increasing the amount of mass & airgap to counter any triple-leaf effect. Have you considered how you are going to ventilate (breathe) and dehumidify the completely sealed studio and isolation booth? HVAC or split air conditioning and active ventilation/heat recovery? Dan

Thank you Dan for your answer, I've actually been here reading and trying to learn the whole time 8) yes that iso/vocal booth is build and waiting to be finished, I will post measurement of it in following post. "studio" part is not yet started. I understand that this our "normal" way of building makes the outer leaf very weak compared to everything I normally read in this forum, I think that we have to structure that get denser as we move in structure from outside to in. (ie. plastic near the inner wall and something that breaths on the outside.) the outer wall is not caulked. inner wall is chipboard that looks like this: https://www.builderdepot.co.uk/media/ca ... as=700:700 and you pretty much sum up what I have been thinking this whole time:) I thought about what if I would convert the whole garage, but that would be overkill as I'm planning to use only half. I'm bit scared that messing with the moisture barrier could give me some sort of problems in future, all though I think it could be done by removing barrier only from the 2old walls that would be outer leafs and putting new moisture barrier 2 new walls. but leaving old walls as they are and building new room sound like the best solution for me in this case. I tried to search information on what would be the most beneficial place to add mass/thicker walls in this kind of case but didnt find anything good: I'm thinking that would example in this case be best to add layer of gypsum to my existing walls before building my studioroom or better to leave middle leaf "weak" and make the inner leaf doublelayer of gypsum etc? and for the ventilation I'm thinking Gregwor's Silencer Box-design, my vocalbooth/ isolation box has test version and it's running with pc-fan and seems to work ok.( I know that pc-fans are not really powerfull enought to work like this with load and I'm looking for options for the studio room) I will use existing air inlet and outputs but with added silencers. Once this is running I will later get something like mini-split for the cooling/heating.

and this is the "non official, non calibrated" measurement: pa-speaker measured inside the booth vs. mic 1m away from the booth. (inside garage, on all 3 sides of booth, averaged response) I didnt change any settings between measurements so this should give relatively realistic result. After this I also measured with SPL-meter inside booth 100dB and when going outside garage it was around 55dB Edit: and micbooth isnt floating, its just 2x4 frame on two walls and one layer of gypsum sealed best I could. walls have 10cm of paroc COS5( this was said somewhere in here to be close to OC703) ceiling has 10cm acoustic panels and ~20 cm fluffy polyester.

and that is about as much isolation as you'll get since the structural transfer is not the predominant sound source as well as the window.

gullfo wrote:

and that is about as much isolation as you'll get since the structural transfer is not the predominant sound source as well as the window.

Would you say there is any benefit (isolation wise, sound leaking outside from garage) in building a"floating room" vs. just one rigidly connected wall splitting the garage? edit: in this case if I would build it like pictured 3-leaf design, but reasonable airgaps to existing walls and floating room having glasstiles/dB-window etc. inplace of window? I'm just strugling on deciding what are the most optimal solutions for me, dont want to build something just to get more worse results:)

moi? i would build a set of inner rooms which are decoupled from the existing walls and ceiling - only sharing the earth damped concrete floor. the outer walls would be sealed properly and mass enhanced (drywall between studs on walls, and between rafters underside of roof - or inside-out on top of joists / truss bottom chords).

gullfo wrote:

moi? i would build a set of inner rooms which are decoupled from the existing walls and ceiling - only sharing the earth damped concrete floor. the outer walls would be sealed properly and mass enhanced (drywall between studs on walls, and between rafters underside of roof - or inside-out on top of joists / truss bottom chords).

Moi! :) Do you mean dissambling my current inner leaf(convert this to 2-leaf design and beef up my outer wall etc) or just cover my current walls with layer of gypsum? download/file.php?id=70590 I think I have to choose from 3-options 1)dissassemble inner walls, beef up my woodfiber-board with gypsum and seal everything up, then build my floating inner room. -best isolation but I'm scared where will I mess up my walls dew point and there might be issues with how to build moisture barrier to one side 2)coat my walls with gypsum and build floating inner room -3-leaf design, faster to build but will I create some unwanted resonances that will mess the isolation 3)just build splitting wall across the garage. -simple and fast but isolation will not be improved. I hate these calculations, but I've been trying to do some calculations for my current garage walls: TL of inner leaf is 31dB and outer leaf 26dB and F0 was 0.889(?real or some error? :) but for 3-leaf designs it's hard to find any info or (some simple) calculations for normal persons. viewtopic.php?f=1&t=21289 I understand that it gets really complex, but I would like to know some rough values what to expect. from this one I found that https://ocw.upj.ac.id/files/Textbook-AR ... NGUNAN.pdf if I build it like this then I believe I should beef up the "middle" leaf "Here the triple panel has a symmetric construction with the center panel having twice the mass of the outer panels and equal air spaces on either side"

so, if you're already far along in the construction, i'd add more mass to the existing walls with some viscoelastic damping like green glue (not a glue) product on each layer. i'd skip the "floating" room idea, decouple from the exterior wall, but don't float it.

gullfo wrote:

so, if you're already far along in the construction, i'd add more mass to the existing walls with some viscoelastic damping like green glue (not a glue) product on each layer. i'd skip the "floating" room idea, decouple from the exterior wall, but don't float it.

Thank you Glenn! Garage is built, that mic/isolationbooth is built but havent started splitting this garage into studio space yet. wall structure is currently like pictured in this: viewtopic.php?f=1&t=22175#p156274 this house & garage were built in 1997 but were missing some permits&paperworks :evil: but luckily we have that now sorted. I'm sorry but I dont get what this means;

gullfo wrote:

decouple from the exterior wall, but don't float it.

I might have mixed some terms, but I thought that it would be good to build this room so it touches only concrete floor (ie.no rigid connections elsewhere to old walls/ceiling) or do you mean resilient channel or how can I decouple it?:roll:

yes, the wall can sit on the concrete floor, however, the rest of the structure should be decoupled from the existing walls and ceiling. if necessary or required - use isolation bracing (check Mason Industries and Kinetics for products) which are used to stabilize walls and stabilize/suspend ceilings esp in seismic areas, high winds, etc.

I made few rough options: yellow is insulation and red is gypsum. cavity always filled with insulation a)inside-out walls b)normall walls c)combination of them I understand that symmetry plays also big part of what the final outcome is, so should start to focus on it allready at this point before any acoustics is designed? Does it matter much what kind of insulation I use between the walls? I'm hoping to eventually have my speakers(genelec 8260, yeah shaped lovely) soffitted and use Johns small studio examples from here: viewtopic.php?t=5457

inside-out has some nice features because it adds an absorption layer into the room. the only downside comes from the amount of air gap between the mass layers - with normal MAM, on 2x4 walls with a 1" air gap between frames, you're at 8" of air. if you flip that, you're at 4 1/2", so depending on the isolation needed, you could bring the inside-out walls in 3 1/2" or use the normal MAM. with mass enhancement on the exterior walls and a full set of mass on the interior, most times the 4 /1/2" gap can be enough. lot's of drums and loud amps, i'd opt for the regular MAM and larger air gap. so i'd pick A. the insulation on the exterior side can be regular pink wall insulation. on the inside - use semi-rigid 703 type or equiv.

slooooowly learning sketchup :)

When dealing with Sketchup make sure you create everything as a group. Make a wall and group it, you can then move it, copy it, and alter it. cheers john

John Sayers wrote:

When dealing with Sketchup make sure you create everything as a group. Make a wall and group it, you can then move it, copy it, and alter it. cheers john

thank you, good point!

slow progresss

I have a small gap between the wall and floor slab, what would be the best filler for this? I would think there would be better things than normal acryllic caulk, but is silicone, butyl-sealant etc good for this? this will not face the full spectrum of outside temperatures we see here (-30 to +30 ish 'C) but definitely bigger changes in tempereture than in normal drywall etc. edit: I think some of the brands I see mentioned alot in this forum are not easily available in Finland ie.Big stretch or that glue that is not really a glue.

look into concrete slap joint mixtures. pretty sure someone in Finland must seal concrete joints with products that are designed for the weather :) maybe swing by a construction product lot and ask. might be an 80lb bag you need to mix, but the key would be to have something which will stay flexible even during deep cold.

gullfo wrote:

look into concrete slap joint mixtures. pretty sure someone in Finland must seal concrete joints with products that are designed for the weather :) maybe swing by a construction product lot and ask. might be an 80lb bag you need to mix, but the key would be to have something which will stay flexible even during deep cold.

thanks! sometimes I just ignore the most obvious solutions thinking that this is now totally different game