Garage -> Studio Build

Hello all, here is yet another garage conversion story. I'm amazed you guys aren't sick of these by now. haha. Before I get started, I wanted to thank everyone on this forum who has contributed to helping people with their DIY studio builds. I have spent the last 5-6 months researching and planning my build, and the information on this forum (and others like Gearslutz and homerecording) has been insanely helpful. So a genuine, heartfelt THANK YOU goes out to those of you who have given your time to help. Ok, my build. The Plan: My wife and I bought our first house (finally), and I am excited to finally be able to build a rehearsal/recording studio in the garage. My goal is to convert the garage to a rehearsal space that contain my drums. I am in 4 bands at the moment, so I have a lot of practicing to do, and it'd be nice to be able to practice without worrying about my neighbors hate me. I have been known to practice for 8-10 hours a day, so simply asking my neighbors to tolerate the noise is not fair to them. Being able to record in there is a close 2nd in terms of priority. I will also likely be having full band rehearsals a couple of times a month. I figure it will take me a year to complete the project, including research, planning, design, construction, and room treatment. Like I mentioned earlier, I have been researching and planning for about 5 months already, and have started construction 3 weeks ago. I am doing the majority of the work myself, so it has been extremely slow going, but that was to be expected. I am working with a structural engineer because of the roof issues i'll explain later in the post, and I will be consulting with an electrician when it comes time to do the electrical (my plans for that will be detailed below as well). I may hire a contractor to help with things I'm concerned about, but I'm really trying to keep this as DIY as possible to keep the costs down. Budget: I originally thought I could do this for $10,000, but after doing some initial research and material sourcing, I realized that number was going to go up. Initially I was looking at a materials cost of around $20,000, but I started to learn more about what REALLY works in sound isolation (again, thanks to forums like this, and Rod's book). I learned that using the right materials IN THE RIGHT PLACE makes more of a difference than MORE materials. I am now working with a materials budget of $15,000 and so far that's looking pretty good. I'm keeping track of every penny spent, so I'm on schedule. I am not including room treatment in this budget, just isolation materials. I will re-evaluate budget when I get closer to treating the room. Isolation Needs I had a friend walk around the property with a spl meter while I played at close to full volume. I had him take measurements at key points around the property. My biggest concern is my neighbor to the west. His house is about 30 feet from my garage, and i was getting levels of about 81dbC on that side of the garage, and 93dbC in front of the garage where his house is closest to. I am aware that with my budget and construction methods, the absolute MAXIMUM I could achieve would be about 70db of TL... and that's if everything is done perfectly with no mistakes. Realistically I know to expect probably 50db of TL, and if I got that, I'd be OK with it. My budget isn't very big, so planning and making sure I do this right the first time is a priority. Garage Specs The garage is on the smaller side. It was built in 1936. It is unfinished which is nice because that's less work to take down any drywall or plywood on the interior and I can get right to beefing up the exterior leaf. The exterior is stucco (approx 1 inch thick), and the roof is simple roof sheathing with roof shingles on top. The studs and rafters are 2x4 (1 7/8 x 3 5/8), and the garage door is metal. The inside measures from stud face to stud face 17' 7 1/2" x 15' 4" x 8' 1" high (to the top of the top plate). The peak of the roof is 11' 4", and is a 4/12 roof pitch. There is a ridge board (not ridge beam) that measures 5 1/2" by 3/4". The floor is concrete slab on grade, and in fantastic condition considering how old it is. I took a 4ft level and placed it all over the floor in every possible direction, and it's level with no dips or bumps. there are some small hair line fractures, and a some very small chips here and there, but nothing to be concerned with. There are two horizontal ceiling joists, and 2 diagonal rafter ties. See below. One thing that has been extremely helpful was learning how to use sketchup. It has been outstanding for allowing me to really visualize what I'm going, but also helping me source the right amount of materials. I will post pictures as I go. I hope it makes sense. I have a 40amp sub panel being fed from the main panel in the garage, but I am going to upgrade that to a 60amp subpanel. There is a gable end vent on the same end as the garage door, but no soffit vents or ridge vent, which is going to cause a problem - detailed later in this post. Design Plan for Garage: I will be building a single room, no booths, no separate mixing station. I do most of my recording by myself, so I don't need a separate space for that. Exterior wall will look like this: Stucco > 3/4" OSB > 5/8" drywall (backer rod and caulked around all drywall pieces) pink fluffy inside stud bays as well as cavity Interior Frame (walls and ceiling): 2x6 frame stuffed with pink fluffy 3/4" OSB > Green Glue > 5/8" Drywall > Green Glue > 5/8" Drywall The perimeter of all drywall will be spaced 1/4", and 3/8" backer rod will be stuffed around and caulked. I will be using the staggered drywall installation method I have seen in Rod's book and all over this forum. Ceiling first, North/South walls 2nd, East/West walls 3rd, allowing space for backer rod and caulk. First step is to beef up the existing outer leaf. - I have already installed strips of 3/4" OSB into the stud bays, and secured them in place with wood cleats. I have caulked the edges. - I had a few sheets of drywall left over from a previous project, so I cut those up and filled a few stud bays. I will fill the rest when I am ready to order more drywall. I left a gap of about 3/8" around the drywall to stuff with 1/2" backer rod. I then caulked (didn't take picture of that yet). I have decided that 3/8" gap is too big, because if there are uneven studs (which there are plenty of), it causes much larger gaps. So I have decided after these bays I will be doing 1/4" gap with 3/8" backer rod. The 3 walls including one gable end are complete. I can't do the ceiling yet because of a few problems. I want to remove the ceiling joists to allow for more ceiling space. this was the first reason I contacted a structural engineer (the second was to make sure the structure could handle all the added mass). I had seen a thread of someone else's build on gearslutz, and they had an architect design small gussets that could be attached at the top to help support the structure when removing those ceiling joists. I showed my SE the design, and he was not ok with it. He was too concerned that with the added mass, the walls would lean and the roof would collapse. Apparently that's not good. So we came up with a gusset idea, but on a MASSIVE scale. His design calls for rafter ties no less than 2ft from the ridge, with plywood on both sides. Here is his design... I have a few concerns with this design, but I won't go into that right now. We're still working on fine tuning it at the moment. But a bigger problem is venting. I was really close to ready to start working on the ceiling when I remembered reading about how important it is to vent the roof. So I started looking into it and learned that I have some things to work out first. We'll get to my questions at the end. I will be building a new inner frame to create the room in a room. I will be using 2x6s for all framing with 24 OC, because Rod says that's the way to go. lol. I will be filling the cavity with pink fluffy. I will be closing off the garage door, ceiling it, and building a wall to connect to it to make it one massive outer leaf. I plan on using a 2 door system for entry into the space. Electircal: To achieve maximum isolation, I plan on having the sub panel, and all outlets face mounted onto the drywall so there is just 1 hole in the wall where the power is being brought into the room. I will be using metal conduit and metal boxes so I can run a STAR grounding system with isolated receptacles for all studio/music gear. HVAC I will be using a wall mounted mini-split for heating/AC, and an ERV for air circulation. I have seen many baffle box designs and haven't quite figured out how I'm going to do that yet, but it is on my mind to get planning with it because I need to figure that out before I can start building the interior frame. I know I will be placing baffle boxes inside the room, even though they will be quite large. Problems/Questions: 1 - My immediate concern is the roof venting issue. As I see it now, I have 2 options. a: build a warm roof b: figure out how to vent each stud bay along the ceiling, and put vents in the soffits at the roof edges. Right now, the soffits are completely closed off. How can I vent each stud bay? Is that even possible? Would I have to dismantle the roof to do it? If that were the case, I figure it'd be easier/cheaper to just do a warm roof. My only hesitance to that is the roof was just replaced like 4 years ago. It's in great condition. Am I on the right track in my thinking here? 2 - Another concern I have is a moisture barrier for the garage door. When I go to seal it up, do I need a moisture barrier, and where do I put it? 3 - When it comes to ERV for air circulation, I want to make sure I have this correct. The projected volume of my room will be roughly 1,900 cubic feet. (14x15x9). 1,900/60 puts me around 32 CFM (cubic feet per minute). If my unit can push 40 CFM, is that sufficient? Or am I not calculating this properly? How does the rest of this look? I commend anyone who is still alive after reading this. lol.

Ok I have a bit of an update. I had a couple of different roofers come by to give me a quote on installing a hot roof. While both quotes were WAY more money than I had anticipated, doing a warm roof seems like a much better option than installing a ridge/soffit vents and creating a 3 leaf roof. It's also not so much the 3 leaf that's bothering me, but how much more difficult it is going to be to isolate the middle leaf once I have my huge gussets installed. With a warm room, beefing up the outer layer will be fairly straight forward. I just have a couple of questions. Originally, I had planned on putting in 3/4" OSB in between the rafter bays (like I did in between the stud bays of the walls), and then putting 5/8" drywall in the rafter bays (again, the same as the walls). That would give me 3 layers on the roof (7/16" OSB roof sheathing > 3/4" OSB > 5/8" drywall). If I do the warm roof, the existing shingles will be removed, and a water/ice sealer will be installed on the existing 7/16" OSB roof deck. Then 2" Thermasheathing insulation boards (R14 value), then 7/16"OSB again (for a nailing surface for the shingles), then shingles. I already have the 3/4" OSB that I was going to put into the rafter bays... but can I just use that 3/4" OSB instead of new 7/16" OSB as my top layer nailing surface for the shingles? Would this help me maintain my isolation? If this is possible, this would actually save me money (since I already have the 3/4"OSB, and wouldn't need to purchase more 7/16" OSB), and a lot of time since I won't have to install it in the rafter bays. So instead of this I'd get this Would this work in keeping that entire exterior leaf one giant solid isolated leaf? Does it matter if the 3/4" OSB is above the insulation, or below the roof deck?

I hope someone with local build experience chimes in. Many of the words you use are unknown here. So I can only speak on Acoustic issues. The various harder insulation, Poly this and that, are thermally let's say 3 times more effective than fibre. Here a typical 4" board replaces a foot of fibre. Our houses have BER thermal certs which affect their sale value. But these boards have pretty much zero acoustic effect or benefit. Also here, and may not apply to you at all, warm layers can cause problems with condensation, mould, rot. So hopefully a practical or professional builder with USA Code and other knowledge will help out now? Have you got Rod Gervais' book, Build it like the Pros?

Hi, Here's a diagram I've drawn of how you can build a cold roof and still maintain your air tight 2 leaf isolation assembly. This diagram is for a cathedral ceiling, but the same applies with a flat ceiling too. It's not a 3 leaf assembly really since the roof has lots of holes along the top and bottom (vents), it is merely a rain screen for your 2 leaf assembly. If you have the space you can apply the outer leaf mass layers directly on the bottom of the rafters instead of between the rafters, that will depend on how big you need your air cavity. Vent your soffits, there needs to be a continuous 10000mm2 air gap, so if using the 70mm round soffit vents that equals 1 vent every 160mm. And also vent your ridge. I find this calculator super useful for working out exactly what you need in order to meet building regs: https://www.owenscorning.com/roofing/co ... calculator Hope that helps, let me know if you have any questions. If you go the warm roof route then that's great, much more efficient, simpler and faster. However make sure it is done 100% correctly otherwise you will have terrible problems with moisture rotting out the entire place. 1 little hole or breech in the VCL in the wrong place could cause moisture to get in but not be able to dry out (due to zero vents) which will spread until it's too late... you'll only notice it once water starts dripping down onto your gear from above which is bad enough, but then you'll realise that the entire roof and inner and outer leaves will need to be redone! It is a very simple and in theory easy way of building a roof and it should be excellent if done correctly, but if you're not going to install it yourself then I would be watching the roofers/builders like a hawk. There's a lot of people out there that claim to know what they're doing but in reality do shoddy workmanship and rip people off. If it were me, I'd rather get up there and do it myself since all the materials are relatively light weight once the roof deck is on. Paul

DanDan wrote:

I hope someone with local build experience chimes in. Many of the words you use are unknown here. So I can only speak on Acoustic issues. The various harder insulation, Poly this and that, are thermally let's say 3 times more effective than fibre. Here a typical 4" board replaces a foot of fibre. Our houses have BER thermal certs which affect their sale value. But these boards have pretty much zero acoustic effect or benefit. Also here, and may not apply to you at all, warm layers can cause problems with condensation, mould, rot. So hopefully a practical or professional builder with USA Code and other knowledge will help out now? Have you got Rod Gervais' book, Build it like the Pros?

Hi DanDan, Thanks for chiming in. First off, yes, I have Rod's book and have gone through it several times (and am currently going through it again, haha). The poly iso insulation is not meant for soundproofing (but for thermal insulation), my understanding is that as long as it maintains contact with the OSB, it is keeping the leaf one solid leaf and not causing a 3rd leaf. @Paulus87, I've seen you post that diagram before. It is very clear, and I was about to start cutting the ridge and soffit vents when I revisited the warm roof option. My concern with doing the ridge/soffit vent idea, is the large gussets that I will be installing in the rafters makes it impossible to add the layers directly to the underside of the rafters. So I would have to put the layers inside the stud bays, and while that is totally doable, it's just a lot of work. One of the roofing guys actually suggested I do the warm roof myself. He saw what I was doing, all the work I had done and was like, "Dude, you're pretty handy, you can probably do this yourself." Another roofer with a different company didn't think I needed to do a warm roof OR vent. He thought it was good enough the way I have it (which I don't think is correct). The only reason I don't want to do the roof myself is because I have never done any roofing before. I guess I can start watching videos on how to do a roof. Maybe I'll be able to learn just enough. In your drawing, you have the vapor barrier on the room side of the studs of the interior wall. Does it matter what climate you're in when determining where that vapor barrier goes? What about the moisture barrier for the garage door? Do I need it, and where would it go? Thanks for chiming in. You're help and expertise has been extremely valuable.

Jag94 wrote:

DanDan wrote:

I hope someone with local build experience chimes in. Many of the words you use are unknown here. So I can only speak on Acoustic issues. The various harder insulation, Poly this and that, are thermally let's say 3 times more effective than fibre. Here a typical 4" board replaces a foot of fibre. Our houses have BER thermal certs which affect their sale value. But these boards have pretty much zero acoustic effect or benefit. Also here, and may not apply to you at all, warm layers can cause problems with condensation, mould, rot. So hopefully a practical or professional builder with USA Code and other knowledge will help out now? Have you got Rod Gervais' book, Build it like the Pros?

Hi DanDan, Thanks for chiming in. First off, yes, I have Rod's book and have gone through it several times (and am currently going through it again, haha). The poly iso insulation is not meant for soundproofing (but for thermal insulation), my understanding is that as long as it maintains contact with the OSB, it is keeping the leaf one solid leaf and not causing a 3rd leaf. @Paulus87, I've seen you post that diagram before. It is very clear, and I was about to start cutting the ridge and soffit vents when I revisited the warm roof option. My concern with doing the ridge/soffit vent idea, is the large gussets that I will be installing in the rafters makes it impossible to add the layers directly to the underside of the rafters. So I would have to put the layers inside the stud bays, and while that is totally doable, it's just a lot of work. One of the roofing guys actually suggested I do the warm roof myself. He saw what I was doing, all the work I had done and was like, "Dude, you're pretty handy, you can probably do this yourself." Another roofer with a different company didn't think I needed to do a warm roof OR vent. He thought it was good enough the way I have it (which I don't think is correct). The only reason I don't want to do the roof myself is because I have never done any roofing before. I guess I can start watching videos on how to do a roof. Maybe I'll be able to learn just enough. In your drawing, you have the vapor barrier on the room side of the studs of the interior wall. Does it matter what climate you're in when determining where that vapor barrier goes? What about the moisture barrier for the garage door? Do I need it, and where would it go? Thanks for chiming in. You're help and expertise has been extremely valuable.

Ok - the guy that said to leave the roof as it is without vents or doing a warm roof is either an idiot or didn't fully understand what was going to happen with your build. If you were to leave the room as it is without loads of insulation up tight against the roof deck or walls and didn't seal the hell out of every seam/gap/crack then sure, it would probably be fine. But, as soon as you put insulation (especially up in the ceiling) with no air gap or venting then it will for sure sweat. Vapour barrier goes on the warm side of the insulation in cold climates like the UK. check with your local building regs to find out where it needs to go in your particular case. You may or may not need it... OSB is often used as an acceptable vapour barrier in passive house builds, which is very similar to how we build studios, so you might be fine without one... just check. Regarding your garage door, well since you're blocking it up, just treat it like the rest of your wall, wherever you put the vapour barrier on your wall will follow with the garage door as well. Moisture barrier, are you talking about to stop rain getting in? Well you need to do that for your walls as well... so it'll be the same as whatever you do for that, some sort of external cladding I'm guessing? Paul

Yeah, I don't think he fully understood what I was doing, although he did seem to be very knowledgable about roofing. Also, I've seen you calling it a "warm roof" many times, but I don't think people refer to it that way here in the states. When I said "warm roof" I got blank stares, but then when they explained their process, they were explaining exactly what a warm roof is, but just not using the term warm roof. ha. When I type in warm roof, mostly everything that comes up is in the UK, and a LOT of it is for flat roofs. I'm having a hard time finding resources for the "warm roof" here in the states. It looks like they use the term "hot roof" here in the states, although it doesn't seem to be common. I'll keep checking the vapor barrier requirements here in Los Angeles.

Jag94 wrote:

Yeah, I don't think he fully understood what I was doing, although he did seem to be very knowledgable about roofing. Also, I've seen you calling it a "warm roof" many times, but I don't think people refer to it that way here in the states. When I said "warm roof" I got blank stares, but then when they explained their process, they were explaining exactly what a warm roof is, but just not using the term warm roof. ha. When I type in warm roof, mostly everything that comes up is in the UK, and a LOT of it is for flat roofs. I'm having a hard time finding resources for the "warm roof" here in the states. It looks like they use the term "hot roof" here in the states, although it doesn't seem to be common. I'll keep checking the vapor barrier requirements here in Los Angeles.

Yes you call it a hot roof, but a flat warm roof or a pitched warm roof, hot roof, whatever is the same process and design. It’s really that simple. Check out Matt risinger on YouTube, he’s currently rebuilding his house to passive house standards including pitched warm roofs. Btw, regarding your question about the order of your roofing sandwich, depending on your local codes you can actually just put an EPDM rubber roof straight over the top of the rigid insulation, as it is not going to have regular footfall. So that means your roof deck would be your outer leaf with the vapour control layer over that, then rigid insulation and then covered with the rubber. Paul

Paulus87 wrote:

Yes you call it a hot roof, but a flat warm roof or a pitched warm roof, hot roof, whatever is the same process and design. It’s really that simple. Check out Matt risinger on YouTube, he’s currently rebuilding his house to passive house standards including pitched warm roofs. Btw, regarding your question about the order of your roofing sandwich, depending on your local codes you can actually just put an EPDM rubber roof straight over the top of the rigid insulation, as it is not going to have regular footfall. So that means your roof deck would be your outer leaf with the vapour control layer over that, then rigid insulation and then covered with the rubber. Paul

Ahh, gotcha. Thanks for the tip on Matt Risinger... I'll check it out. Interesting. But if I put another layer of OSB for a nailer surface for the asphalt shingles, wouldn't that count as more mass to my leaf? It would be way easier to install it in full sheets on top of the roof deck rather than in between the stud bays below the roof deck. no?

Jag94 wrote:

Paulus87 wrote:

Yes you call it a hot roof, but a flat warm roof or a pitched warm roof, hot roof, whatever is the same process and design. It’s really that simple. Check out Matt risinger on YouTube, he’s currently rebuilding his house to passive house standards including pitched warm roofs. Btw, regarding your question about the order of your roofing sandwich, depending on your local codes you can actually just put an EPDM rubber roof straight over the top of the rigid insulation, as it is not going to have regular footfall. So that means your roof deck would be your outer leaf with the vapour control layer over that, then rigid insulation and then covered with the rubber. Paul

Ahh, gotcha. Thanks for the tip on Matt Risinger... I'll check it out. Interesting. But if I put another layer of OSB for a nailer surface for the asphalt shingles, wouldn't that count as more mass to my leaf? It would be way easier to install it in full sheets on top of the roof deck rather than in between the stud bays below the roof deck. no?

If you're going to use shingles then yes of course, you'll have to do it that way. But if you decided on a rubber roof (wayyyyy quicker and much more durable) then you wouldn't need to put the OSB between the rafters, you can just put it on top of the existing roof deck, as many layers as you want (providing there is no vapour control layer already down - this must go on last, under the rigid insulation which is on top of your roof deck). Paul

Paulus87 wrote:

If you're going to use shingles then yes of course, you'll have to do it that way. But if you decided on a rubber roof (wayyyyy quicker and much more durable) then you wouldn't need to put the OSB between the rafters, you can just put it on top of the existing roof deck, as many layers as you want (providing there is no vapour control layer already down - this must go on last, under the rigid insulation which is on top of your roof deck). Paul

I looked into EPDM rubber roofs a bit, and it says they're for flat or low-slope roofs. I guess the definition of a "low-slope" roof is 3/12 pitch or less. My roof is somewhere between 4/12 and 5/12. Would a EPDM roof work?

Jag94 wrote:

Paulus87 wrote:

If you're going to use shingles then yes of course, you'll have to do it that way. But if you decided on a rubber roof (wayyyyy quicker and much more durable) then you wouldn't need to put the OSB between the rafters, you can just put it on top of the existing roof deck, as many layers as you want (providing there is no vapour control layer already down - this must go on last, under the rigid insulation which is on top of your roof deck). Paul

I looked into EPDM rubber roofs a bit, and it says they're for flat or low-slope roofs. I guess the definition of a "low-slope" roof is 3/12 pitch or less. My roof is somewhere between 4/12 and 5/12. Would a EPDM roof work?

Fully adhered rubber roofs can be used at any pitch. Here’s more info: https://www.buildings.com/article-detai ... ic-roofing Whether you choose rubber or shingles, either of your designs will work. Just check with your local code regarding not roofs as well manufacturers of any products you use. Paul

Quick side question. At what point does a layer of mass become a separate leaf? For example, if you have 2 sheets of drywall, how much space in between those to sheets is necessary for it to be considered 2 leafs instead of one? Here's my situation. My roof rafters and 1st layer of roof sheathing are separated by wood slats that are 7/8" thick. So if I were to put drywall in between the rafters, there would be 7/8ths of an inch between the drywall and the roof OSB. Would this constitute a break in the leaf, essentially creating a second leaf? How big of a deal is it if the external leaf is about 2 feet away from the inner leaf? Does that amount of space in between the inner leaf and the outer leaf help? Here is a picture to give an idea of what I mean.

Hello & howdo' Jag 94? Apols for the brevity of my reply but I've got a lot on at the mo'!

if I were to put drywall in between the rafters, there would be 7/8ths of an inch between the drywall and the roof OSB.

If you placed your drywall in between the wood slats instead of the rafters you could preserve the continuity of your outer leaf. It would be trickier to build without a doubt but would improve isolation in my view. Also, have you had a structural engineer inspect the structure? I'd recommend you do if you haven't already, so you can be certain that adding the extra mass is safe. Best wishes, John.

John Steel wrote:

Hello & howdo' Jag 94? Apols for the brevity of my reply but I've got a lot on at the mo'!

if I were to put drywall in between the rafters, there would be 7/8ths of an inch between the drywall and the roof OSB.

If you placed your drywall in between the wood slats instead of the rafters you could preserve the continuity of your outer leaf. It would be trickier to build without a doubt but would improve isolation in my view. Also, have you had a structural engineer inspect the structure? I'd recommend you do if you haven't already, so you can be certain that adding the extra mass is safe. Best wishes, John.

Hi John, Thanks for the reply. First, in my post I explained that I hired a SE for a couple of reasons (I don't blame you for not reading that insanely long first post). The first reason is to - like you said - make sure the structure could hold the added weight. The second, was because I wanted to remove the existing rafter ties to increase ceiling space. Together we designed extremely large rafter ties and gussets that will sit a foot higher and will make sure the walls don't lean/roof collapse, and that the roof structure is strong enough for the added mass. As far as cutting up drywall and putting in between the slats - kill me now. haha. I went and bought 1" EPS foam, and started cutting that up to put in the slats, so that when I put the drywall in between the rafters, it would help keep the continuity of the leaf. Cutting the foam is a pain in the ass, but surely it's easier than cutting up the drywall. I just started to think if it was really necessary, because if not, it would save me a TON of time.

Hello again Jag94,

I explained that I hired a SE for a couple of reasons (I don't blame you for not reading that insanely long first post).

My mistake - I usually devote more time to reading threads & researching relevant info but (as per my disclaimer) I'm knee deep in my build at the moment & my recent experience on the forum is that most members won't acknowledge a reply, so I have decided to scale my efforts accordingly.

I hired a SE for a couple of reasons

:thu:

As far as cutting up drywall and putting in between the slats - kill me now.

I feel your pain dude - I have recently cut 36 panels out of cement board, all mounted on their own individual softwood frame, fitted in between the rafters of my garage and none of them were identical dimensions. I need to add the same number of OSB panels next week and it's painstaking work. Now I think about it, nobody said it would be a picnick!!

Cutting the foam is a pain in the ass . . . I just started to think if it was really necessary

I understand your dilemma - the one lesson I've learned from this whole process is that studio design is a succession of compromises. My view is that you are doing the right thing by completely filling the gap; if it wasn't a pain in the arse, then everyone would be doing it! Looking forward to hearing more about your project. ATB John.

My mistake - I usually devote more time to reading threads & researching relevant info but (as per my disclaimer) I'm knee deep in my build at the moment & my recent experience on the forum is that most members won't acknowledge a reply, so I have decided to scale my efforts accordingly.

I apologize if my reply came across the wrong way, I didn't mean to be crass. I am sincerely thankful for anyone who takes the time to reply as obviously everyone has their own stuff happening.

I feel your pain dude - I have recently cut 36 panels out of cement board, all mounted on their own individual softwood frame, fitted in between the rafters of my garage and none of them were identical dimensions. I need to add the same number of OSB panels next week and it's painstaking work. Now I think about it, nobody said it would be a picknick!!

No they didn't. And I knew that. But HOW painstaking I didn't know. But I value the experience of getting my hands dirty doing the work myself, as I'm sure you do as well. Having to cut each of those panels and them all being different dimensions is hellish work. I did the same with my OSB in between the studs. It's not fun.

I understand your dilemma - the one lesson I've learned from this whole process is that studio design is a succession of compromises. My view is that you are doing the right thing by completely filling the gap; if it wasn't a pain in the arse, then everyone would be doing it! Looking forward to hearing more about your project. ATB John.

Yeah, Rod mentions it several times in the book, and I'm starting to really understand it. I guess I'll just keep trucking along. Thanks again for checking in.

Little update here. I've decided to go with a hot roof even though it is causing me to go several thousand dollars over budget, but I was able to negotiate the price since I'll be doing some of the work myself, and I already have some of the materials. I'm filling the gaps in between the slats on the underside of the roof with 1" EPS foam. I'm using expanding spray foam to fill any gaps that I can't get the foam into. It's time consuming, but I think it's worth it. Next is to start building the large gussets that will attach to the rafters. I'll post more details about this when it's done. While this is happening, I've been thinking a lot about HVAC and electrical. I feel like I have an above average understanding of what I want and need to do with the electrical, but I do have some questions I'll get to as I progress with the project. As far as HVAC, here is what I WANT to do. I already have a ductless mini split system that I will be using to heat/cool the room. As far as ventilation, this is where I'm a little stuck. The garage is small. When I build the room inside the room, it is taking significant square footage away, especially since I'll be lowering the ceiling (it will no longer be a cathedral ceiling, even thought that's what I would prefer). The total cubic footage will be around 1900 cubic feet. Actually a little less. I don't have a separate room to house a full size ERV unit, and then run ducts to and from it. So I need to find a unit that can be installed inside the room, and have the ducts go to baffle boxes inside the room, into the wall space, and then exit the exterior with outdoor baffle boxes for the outer leaf. There are basically two products I'm looking at, and both of them say they are rated for room ventilation for spaces up to like 1,700 sqft. Now notice that's sqft and not cubic feet. But I don't know if the specs on these units takes into account how many people are in the room. One unit can do a maximum of 40cfm, the other 75cfm. Is the CFM rating more important than the size of the room rating? I will be using this space MOST of the time with just me in it. Probably 90%-95% of the time. The other 5%-10% will have anywhere from 2-5 people in there. So I'm assuming the unit that can handle 70cfm is probably the way to go. Is there another way I should be thinking about this?

Is there a recourse for learning how to build a frame? I understand the concepts and know how to build a single wall, how to cut rafters, frame a door, and some other basic aspects, but I'm looking for a more in depth tutorial. Something that will cover everything, putting it all together. That would include proper connectors, how to frame a gable end wall, how to make sure the frame is strong enough for the mass I want to put on it, etc. I've been google searching and watching a lot of youtube videos, but since it's a single room, I'm getting a lot of "how to build a shed" or "how to build a shed roof" kind of stuff. I'm looking for a more comprehensive recourse. Any books anyone can recommend?

Ok so after a bit more research, and re-reading Rod's book, I feel like I have a LITTLE better understanding of the HVAC situation. HVAC is complicated. Here's what I have so far. Estimated dimensions of finished interior room: 15' 3" x 14' 3" x 8' 6" approx 1800 cubic feet. With an ideal 6 room changes per hour, that's approx 10.700 cubic feet per hour. Most everything is categorized in cubic feet per minute (not hour), so divide that number by 60, and you get... 10,700/60 = ~178 CFM The Ductless Mini-Split I will be using has these specs: High speed - 294 CFM Medium speed - 212 CFM Low Speed - 147 CFM So the split system will be able to heat/cool the room adequately. To make sure I'm getting enough fresh air into the room, I need 1/4 to 1/2 of the room circulation rate. 40% is a good number to use to estimate. So 178 x 40% = ~71 CFM The HRV I want to use has these specs: High speed - 71 CFM Medium speed - 53 CFM Low speed - 35 CFM. So far we are looking good. Here's the situation I'm inI will be using this HRV unit. HRV UNIT This unit is designed to be installed INSIDE the room. The incoming air and exhaust vents are on the unit itself. It has two 5" ducts on the back that are supposed to go straight through the wall (using duct extenders) and brought straight outside. Obviously this will not work for sound isolation. I have been reading and re-reading this post by @gregwor (6th post down with the Duct charts). GREGWOR'S POST I will be putting the two baffle boxes inside the room. I am aware that they can be quite huge, but that's OK. It's my only option, and well, that's how it goes. I plan on making them pretty beefy too, 3/4" OSB, and 2 layers of drywall (same as my inner walls). I have 3 goals. 1) Make sure I'm getting fresh air in the room, and stale air is being brought out. 2) Make sure the air is conditioned properly. 3) make sure my drumming does not get out of the building through the ducts. I DO NOT care about the HRV/Mini-Split system noises inside the room. 80% of the time it is just going to be me in the room practicing. 10% will be me recording, 5% will be full band rehearsals, and 5%... well, I don't know yet. But when I am recording, it is most likely going to be just me, so if I need to turn down or turn off the systems to eliminate the noise for 5-10 minutes at a time, I'm perfectly fine doing this. And in all likelihood, the noise won't be enough to bother me during recording anyway. here is a sketchup of my idea. It is a VERY rough sketch, but just enough to give you an idea. The HRV will be on the wall to the left of the mini-split. The fresh air vent on the HRV is on the right side, so that air will hit the mini-split immediately after leaving the vent. Both ducts will go down and enter the baffle boxes. The boxes will hit the south wall and the air will be brought outside via ducts inside the south wall. I just need help figuring out how big these silencer boxes need to be, and how big of ducts I need to use inside the wall. This post was edited with updated information.

Update on recent progress. I sealed the sill plate (bottom plate) on the exterior frame. I used DAP 230 caulk, and then put Wigluv seal tape over it. There will be absolutely zero air, water, bugs, sound getting through the exterior frame. The garage door is completely sealed from the inside and out. I caulked (maybe over-caulked?) every possible spot on the inside of the door, and then did the same on the outside of the door. I will be applying THIS "sound deadening" paint onto the interior. Once that's on, I'll put EPS foam into the panels of the garage, and then build a wall to push right up against it, to create a complete, very mass heavy outer leaf. I'll post pictures as I complete each step. I also added 2 layers of 5/8" drywall to the inside of the roof overhangs. The exterior is almost complete. Once the garage door is done, I can finally build the interior frame. It's getting close.

Progress Update: I coated the door with the second skin paint stuff. I did two coats, and the second coat was really thick, as that is what the manufacturer recommends. I used a spray gun, and it went on pretty easily. It's a very strange consistency though. I knocked on the door before and after putting the paint on, and it definitely lowered the vibration of the door. I cut up the EPS foam to the correct sizes to fit in the panels of the door, but I'm waiting for the paint to completely cure before I put the foam into the panels. The manufacturer says it will take 7-14 days, so it's kind of good I'm going on vacation for 10 days. I also built the frame of the wall that will be up against the door. I just need to put the OSB on it before it gets lifted up and into place, then I need to cut the drywall to put in the bays. After that, I can finally start building the inner frame. I'm still researching ways to make the HVAC system work. I'm wondering if I can have the HRV unit penetrate the inner wall, and add mass to the other side of the frame to make a large cavity for the air to flow through. Basically turning the bays of the frame the silencer. But I'm not sure this will work.

Ok so some build updates, design concepts, and some questions. I stuffed the bays of the garage door with EPS foam so that when I stand the wall up, the OSB on the "inside-out" wall will touch directly against the door/foam. There will be no gaps, and it will be one continuous, sealed mass leaf. I attached the OSB to the frame, and with the help of some friends, we stood it up, and I secured it in place. Next up will be adding mass to the stud bays, then caulking the shit out of the perimeter and the drywall in the bays. Thinking a LOT more about the ERV situation, I started putting down on paper (or in this case, sketchup) how this would work/look. I'm not crazy about it because it's going to take up significant space in the room, but I am concerned with making sure I'm getting adequate fresh air in the room when I have 3+ people in there playing music, sweating, breathing hard, etc... as anyone should be. So here's what I'm thinking. There are two ERV units that meet my needed specs. This one and This One The first one is pretty small in dimensions and is much more affordable. It's marketed as an AEV (Air Exchange Ventilator), and by the descriptions, it seems to function much like an ERV or HRV, but for some reason doesn't have the same name. The second one is really slim (albeit longer and wider), so it would sit very high up on the ceiling, effectively not taking up much space at all. It is double the price, but it seems to be a good option. I understand Fantech is a good brand, so I probably can't go wrong with either one. I will put the unit up towards the ceiling as high as I can on the north wall (which is where the garage door is, and where that new wall was built and stood up). The mini split will be on the west wall, and i'll have the fresh air duct feed the air right into the path of the mini split so it gets cooled/heated immediately. The exhaust duct will run along the perimeter of the room so that it's opening is on the opposite side of the room from the fresh air inlet. I imagine this will help make sure the air in the whole room is being adequately exchanged. I can build the silencer boxes so the supply and return ducts from the unit go directly into them, and then they penetrate the wall and take the air outside. This is how I imagine in. Please excuse the crude drawing of it. It's not exactly to scale, but you get the idea. I am thinking about possibly building the silencer boxes inside the wall, instead of inside the room. This would help maintain real estate in the room. What are your guys' thoughts? I also don't know how I'll run the ducting inside the room. I don't want it to look like shit, so I'm hoping maybe I can make it look "industrial", while not completely killing the acoustics in the room. I don't have space above the ceiling to run the ducts, so they have to be run inside the room. any thoughts/ideas/examples of how running a duct in the room could look/work? I am about to build the interior frame, and as soon as I do, electrical and HVAC will need to be figured out so I can make sure I plan everything accordingly for when it's time to put up the OSB and drywall. I am planning on running a star grounding system with isolated ground receptacles. I have done a TON of research on how to do this, but I wanted to put it down on paper to run it by everyone to see if it makes sense, and is correct. Right now I have a 200 amp main panel for the house. There is a ground rod right at the main panel, and another one at the front of the house bonded to the water pipes. Currently there is a 40amp sub panel in the garage, that is fed by 10ga wires in conduit underground. There are 2 hots, 1 neutral, and 1 ground wire. I want to turn this into a 60 amp sub panel, so I'm going to swap the 10ga wires with 6ga wires, and put a 60 amp breaker in the main panel. The only electrical penetration through my interior leaf will be the main power. I will be face mounting all outlets, switches, lights, etc to the drywall, all connected by conduit. As far as the star grounding system goes, I understand that each one of my IG receptacles needs to have a hot, neutral, and insulated ground. Each insulated ground will make a home run to a separate ground bus bar, that will then run all the way back to the main panels ground bus, but never touching the equipment ground bus (or ground conductors) in the sub panel. All the outlet boxes will be metal, and will be connected with EMT conduit, so that will act as the equipment ground for each IG receptacle. So this means I will need to run a 5th conductor (the isolated ground wire) through the conduit back to the main panel. These isolated ground receptacles (I'm thinking about 7 total) will be for audio gear only. I will have regular outlets and circuits for other things like lights, AC, refrigerator, etc. Do I have this right? A diagram would probably be easier to understand. But with everything I've read and seen, this seems to be the correct way to do this. Anything I'm forgetting or should be aware of?

Jag94 wrote:

Ok so some build updates, design concepts, and some questions. I stuffed the bays of the garage door with EPS foam so that when I stand the wall up, the OSB on the "inside-out" wall will touch directly against the door/foam. There will be no gaps, and it will be one continuous, sealed mass leaf. I attached the OSB to the frame, and with the help of some friends, we stood it up, and I secured it in place. Next up will be adding mass to the stud bays, then caulking the shit out of the perimeter and the drywall in the bays.

Not preserved: IMG_3145 small.jpeg

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Thinking a LOT more about the ERV situation, I started putting down on paper (or in this case, sketchup) how this would work/look. I'm not crazy about it because it's going to take up significant space in the room, but I am concerned with making sure I'm getting adequate fresh air in the room when I have 3+ people in there playing music, sweating, breathing hard, etc... as anyone should be. So here's what I'm thinking. There are two ERV units that meet my needed specs. This one and This One The first one is pretty small in dimensions and is much more affordable. It's marketed as an AEV (Air Exchange Ventilator), and by the descriptions, it seems to function much like an ERV or HRV, but for some reason doesn't have the same name. The second one is really slim (albeit longer and wider), so it would sit very high up on the ceiling, effectively not taking up much space at all. It is double the price, but it seems to be a good option. I understand Fantech is a good brand, so I probably can't go wrong with either one. I will put the unit up towards the ceiling as high as I can on the north wall (which is where the garage door is, and where that new wall was built and stood up). The mini split will be on the west wall, and i'll have the fresh air duct feed the air right into the path of the mini split so it gets cooled/heated immediately. The exhaust duct will run along the perimeter of the room so that it's opening is on the opposite side of the room from the fresh air inlet. I imagine this will help make sure the air in the whole room is being adequately exchanged. I can build the silencer boxes so the supply and return ducts from the unit go directly into them, and then they penetrate the wall and take the air outside. This is how I imagine in. Please excuse the crude drawing of it. It's not exactly to scale, but you get the idea.

Not preserved: ERV1 small.jpeg

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I am thinking about possibly building the silencer boxes inside the wall, instead of inside the room. This would help maintain real estate in the room. What are your guys' thoughts? I also don't know how I'll run the ducting inside the room. I don't want it to look like shit, so I'm hoping maybe I can make it look "industrial", while not completely killing the acoustics in the room. I don't have space above the ceiling to run the ducts, so they have to be run inside the room. any thoughts/ideas/examples of how running a duct in the room could look/work? I am about to build the interior frame, and as soon as I do, electrical and HVAC will need to be figured out so I can make sure I plan everything accordingly for when it's time to put up the OSB and drywall. I am planning on running a star grounding system with isolated ground receptacles. I have done a TON of research on how to do this, but I wanted to put it down on paper to run it by everyone to see if it makes sense, and is correct. Right now I have a 200 amp main panel for the house. There is a ground rod right at the main panel, and another one at the front of the house bonded to the water pipes. Currently there is a 40amp sub panel in the garage, that is fed by 10ga wires in conduit underground. There are 2 hots, 1 neutral, and 1 ground wire. I want to turn this into a 60 amp sub panel, so I'm going to swap the 10ga wires with 6ga wires, and put a 60 amp breaker in the main panel. The only electrical penetration through my interior leaf will be the main power. I will be face mounting all outlets, switches, lights, etc to the drywall, all connected by conduit. As far as the star grounding system goes, I understand that each one of my IG receptacles needs to have a hot, neutral, and insulated ground. Each insulated ground will make a home run to a separate ground bus bar, that will then run all the way back to the main panels ground bus, but never touching the equipment ground bus (or ground conductors) in the sub panel. All the outlet boxes will be metal, and will be connected with EMT conduit, so that will act as the equipment ground for each IG receptacle. So this means I will need to run a 5th conductor (the isolated ground wire) through the conduit back to the main panel. These isolated ground receptacles (I'm thinking about 7 total) will be for audio gear only. I will have regular outlets and circuits for other things like lights, AC, refrigerator, etc. Do I have this right? A diagram would probably be easier to understand. But with everything I've read and seen, this seems to be the correct way to do this. Anything I'm forgetting or should be aware of?

Won't the noise from the HRV be a major issue? Or are you not bothered by that? You can build soffits which double as bass traps running around the ceiling/wall junction which conceal your ducting, into which you can also put down lights if you wish. Paul

Paulus87 wrote:

Won't the noise from the HRV be a major issue? Or are you not bothered by that? You can build soffits which double as bass traps running around the ceiling/wall junction which conceal your ducting, into which you can also put down lights if you wish. Paul

Hi Paul, It is an issue, but not a big one. 90% of the time in the room I will be practicing (drums), or having full band rehearsals. So the noise from the machine won't even be noticeable or an issue. It's more important that I keep adequate fresh air pumping into the room when there are 5 musicians sweating/breathing hard. When I'm recording, the large majority of the time it's just me in the room. So if I have to turn down, or even turn the unit completely off when recording to get rid of potential noise getting into the recording, I have no problems doing that. How would the soffits work? would they be completely enclosed? Would that create a 3rd leaf situation? Do you have any examples of how it would look?