Studio Build: Garage Conversion in Los Angeles

[SoWhat]

Greetings Gareth,

it gets everywhere!

Unfortunately, this seems to be a recurring problem for you at the moment.

I hope your fix is moving along.

All the best,

Paul

[ScotcH]

I just did mine ... used Weldbond glue. It's a white glue (like wood glue), but good for a wide range of materials. I thinned it out a bit with water, then brushed on, and stuck the duct line. put weight on it for ~60 minutes, and it's on there good. I did use staples in a couple spots ... works ok, but does rip through the material pertty easily.

[Jag94]

Ok I have another electrical question that I'm hoping you guys can help me out with. I've been reading and reading and reading about isolated ground systems, star ground systems, etc. and I feel like i have this 98% correct, but that last 2% is just killing me... and all the threads I've read don't have the exact situation I'm dealing with. Most of the electricians that I have contacted aren't well versed in audio for studios, so while I've gotten a lot of great advice for general electrical, I'm not getting the info I need for a star ground system.

I understand everyone here is from different countries with different rules and codes, but any advice is appreciated.

A few important notes.

I have a 200amp main service panel at the house. I am running a 60amp breaker off the main panel to a sub-panel in the garage (being run with #6 gauge wires), which is a detached garage. The ground and neutral are bonded together in the main service panel, but will NOT be bonded together in the sub-panel, because that's code.

There are 2 ground rods at the main house (one bonded directly to the ground bus in the main service panel, and one bonded to the water pipes at another point in the house). There is a ground rod for the garage that will be bonded to the ground bus in the sub panel, as it is code for every separate building to have it's own ground rod.

Right now there are 4 conductors running from the main service panel to the sub panel in the garage. 2 hot, 1 neutral, 1 ground. They are running underground in conduit.

I built this space to not have any holes in the walls. All outlet boxes, switch boxes, sub-panel, conduit, etc. will be surface mounted to the drywall.

My plan was to run EMT conduit from the sub-panel to each metal outlet box, and use isolated ground receptacles. The metal conduit and boxes would serve as the safety ground (as they are bonded to the boxes and sub-panel), and a THHN ground wire would be run in the conduit with the hot and neutral wires to connect directly to the ground pin on the receptacles. None of the receptacles will be daisy-chained. They will all have home-runs back to the sub-panel for the hot, neutral, and isolated ground wire.

From what I understand, is for a star-ground to work, all of the isolated ground wires need to come back to a single common star point, i.e. a ground bus bar that is not bonded to the ground bus bar in the sub-panel, or the sub-panel itself. I was planning on installing a box directly under the sub-panel that is fed by PVC conduit (so it is not bonded to the metal sub-panel), and all of the isolated ground conductors would connect to a ground bus bar in this box.

Here's where I'm unsure. I think I screwed up in that I should have run 5 conductors from the main service panel to the sub-panel (2 hot, 1 neutral, 2 grounds). One ground would go from the ground/neutral bus in the main service panel to the ground bus bar in the sub-panel, and the other ground wire would go from the ground/neutral bus in the main service panel to the box that contains a ground bus bar that is not bonded to the sub-panel. This would have all the isolated ground wires coming to a commons star point, and then being brought all the way back to the main service panel where it would be bonded to the ground bus bar, and then to the ground rod at the panel.

But I only ran 4 conductors (due to a confusion/miscommunication with an electrician who I thought understood what was happening). So now, I don't know what exactly to do with the isolated ground conductors coming from each receptacle.

1 - Do I have them all join at a common star point in a separate box that is not bonded, and then splice into the 1 ground conductor coming from the main panel? Would that not defeat the purpose as now the isolated grounds are connected to the same wire that is bonded to the sub-panel ground bus?

2 - Do I just hook up the incoming ground conductor to the ground bus in the sub-panel and forget about the star-grounding thing all together? Do I use plastic boxes, PVC conduit, or other means to just run the electricity without isolating the grounds?

3 - Can I connect the ground wire that is bonded to the ground rod to the isolated ground bus bar, and leave the green ground conductor that is coming from the main service panel bonded to the ground bus in the sub-panel? Or does that ground wire that is bonded to the ground rod HAVE to be bonded to the sub-panel?

4 - Some other option I'm not aware of?

Here is a picture of the inside of the sub-panel in the garage. In the lower left is the ground wire that is bonded to the ground rod just outside the garage. To the lower right are the 4 conductors (2 hot, 1 neutral, 1 ground) being brought in from the main service panel.

[SoWhat]

Greetings Jag94,

While I can't help you with your main issue, I will say something about

I built this space to not have any holes in the walls.

I am going to use surface mount in my build as well. From my understanding, there is usually one penetration (per leaf, obviously) for a standard in-wall box, the all of the surface-mount stuff is run from that. That box can be wrapped with putty pads to regain your isolation.

All the best,

Paul

[kwow]

Hi Jag94

Wow, your place is coming along nicely!

I have some questions about the rubber stuff you got for the door area.

You mentioned:

Next up was the door frame/doors. I have been stressing over this, because at this point, this could make or break the whole studio. Someone posted a pdf on how to build studio doors by John Brandt (I can't remember who), but it had a LOT of useful tidbits in it. The first of which, was the topic covering the gap between the inner/outer leafs at the rough framing of the door opening. I hadn't thought anything about this until I read it, and it made sense. So I bought the rubber stuff, caulked both frames, and installed it.

I read the same pdf and I'm trying to source this stuff in Japan, but having a hard time.
Where did you get yours?
Is the stuff you got for roofing (like John mentions in the pdf)?
What thickness did you get?
It's important that it's rubber and not the tar stuff, correct?
Anything else I should be aware of?

I'm sorry to bug you with questions when you're loaded with things to do.
Thank you in advance!

Keith

[Jag94]

Hey Keith,

I got the stuff from amazon. It's 1/32", which is what JB recommended in the pdf. Not sure if it's specifically for roofing or not. Here is the listing on amazon.

https://www.amazon.com/gp/product/B016C ... UTF8&psc=1

I would imagine having exposed tar material wouldn't be great. But I honestly don't know.

If you do find it, follow JB's instructions on how to install it. The caulk holds it up mostly by itself, I only used a few staples along the top. It was actually quite easy even with me just doing it by myself.

[kwow]

Hey Jag94

Thanks so much for your quick reply and the link! Now I know what the stuff looks like and what it's made of.

Again, your place is looking great! Mine is going to finally start soon (I'm quite nervous about it although excited at the same time - haha)

Keith

[Jag94]

Again, your place is looking great! Mine is going to finally start soon (I'm quite nervous about it although excited at the same time - haha)

Keith

Thanks. It has taken me way longer and cost me more money than I ever thought. But it's almost done. I'd like to tell you the nerves go away, but I'm 10 months in, and I'm scared shitless every day I go out there to work on it in fear that I'm gonna screw it up.

[kwow]

Jag94

I hear you. My nerve wrecking 6 months (or more) is about to start .... scary - hahaha

Thanks
Keith

[Soundman2020]

Source of the post It has taken me way longer and cost me more money than I ever thought. But it's almost done.

Just wondering where you are at with that right now?! I've been away myself for a bit, and sort of lost track of way too many threads, including yours. Maybe you could post an update of where you are now? Is it done already, or are you still working on it?

- Stuart -

[Jag94]

Hey everyone, Sorry I haven't updated in a while. Nobody told me that when you have a baby, you lose every fraction of a second of free time you ever thought you had. I have a LOT to go over, and I don't really have the time right now, but I wanted to mark this date as my official "I've finished my build" date. I still have some room treatment to do, but for all intents and purposes, my room is done. I can't wait to get it all documented and share with you all to close out this thread, but it might take me some time. Since the world opened back up, I've been pretty busy (as I'm sure all of you have too). But hopefully in the next week or so I should be able to update and share my progress. I hope everyone has been well. - JAG

[Soundman2020]

Source of the post Nobody told me that when you have a baby,

Congratulations!!!! Woohhoooo! That sure is good news. I know that was a while back, but that's an immense thing.

Source of the post but I wanted to mark this date as my official "I've finished my build" date.

Another big Congratulations!!!
Wow! A new baby, AND a new studio, both together! You sure are one valiant soldier!
Great news on both fronts.
I'm REALLY looking forward to seeing the updates, photos, explanations, tests, etc. I was following your project with a lot of interest from the start, so it's gonna be fun to see all the final details.
Also, I've been toying with the idea of starting a special section on the forum for "completed studios", and I think you've given me the final push to work on that!

- Stuart -

[Starlight]

Source of the postA new baby, AND a new studio, both together!

Let me join in congratulating you, Jag94, on both counts.