Help a noob wire a detached garage

[v10climber]

Help me garage journal. You're my only hope.

I'm building a 28x35 detached garage here in FL. The building is up and I'm starting to wrap my brain around electrical needs. Currently it's just all exposed studs inside which should make things relatively easy. In general, I have a reasonable grasp of the whole electricity thing. What gets me is all the little things required to make sure everything is up to code. I will be pulling a permit myself (allowed to do that in my county) and as I move through the project I'll no doubt have questions. I'm hoping ya'll can answer the questions. I do have some local acquaintances that are electricians but hoping I can avoid pulling in those favors until I really need it.

I've done hours and hours of reading so far on this and have sketched up a layout (attached). I'm not doing anything particularly complicated. The building has 12 ft walls with storage trusses so I'll need some lighting in the "upstairs" area. But overall it's basic stuff. Standard single gang boxes on the walls, 4ft LED fixtures on the ceiling, a few ceiling outlets for hanging retractable cord reels, an outlet for a lift, outlet for a mini-split A/C, and some exterior lighting.

The house has 200A service. I'm going to run 100A service to the detached garage. There's already a 60A breaker in the house panel that was servicing a shed that is no longer there and the garage is in it's place.

First question:
I'm starting with getting the ceiling conduit boxes in place for light fixtures. My trusses run parallel with the short side of the building. The trusses aren't exactly where I want the lights. So I install blocking between the trusses and nail the ceiling outlet boxes to that right? So the center of my light can be between the trusses? The bottom chord of the trusses is a 2x8. Can I use 2x4 blocking?

A photo of the garage in the current state. Getting painted next week.

The upstairs storage area that I'm working on flooring with OSB now:

 

[bctexas]

If you have a "man cave" area, or a corner with a TV, wire the lights in that area with their own switch. Right now, I have one light switch like you do that lights the entire 2000sf. A light over my desk and TV with a dimmer would be nice but I didn't think of it. Also, if you are going to have a workbench, provide wiring for it - I like outlets on the front of the workbench. And I have a cabinet over the workbench that needs under cabinet lighting - you might want to run that in advance.

Will you need 240 for an air compressor?

Nice looking shop, and the attic storage space is great! Whatcha gonna do in there?

Happy Motoring!

 

[teamextreme]

You don't need outlet boxes for lighting if you're using regular 4 ft strip lights. Just stub the romex out through the drywall and the splice is done inside the fixture. I leave a good 18 to 24 inches poking down so there's plenty of wire to reach where it needs to go inside the fixture. You will still want a block in place to staple the romex exactly where you want the fixture located, and yes, I would just use 2x4 for that purpose.

 

[v10climber]

You don't need outlet boxes for lighting if you're using regular 4 ft strip lights. Just stub the romex out through the drywall and the splice is done inside the fixture. I leave a good 18 to 24 inches poking down so there's plenty of wire to reach where it needs to go inside the fixture. You will still want a block in place to staple the romex exactly where you want the fixture located, and yes, I would just use 2x4 for that purpose.

Thanks that's the confirmation I needed. I had read you could just poke the romex straight through the drywall and make the splice inside the fixture. However, things get a little complicated because of my insulation choice. The building is getting spray foam insulation. Which means I can't do drywall until the insulation is done and I can't do insulation until the electrical is done. And I can't get the electrical inspected with the spray foam covering everything up. So I can't install the light fixtures until the the electrical is finished, building insulated, and drywall up. Which means no drywall to stub the romex through and into the light fixture. So the plan was to basically have the light circuits being a "circuit to nowhere" with electrical boxes. And after everything is in place install the lights and make the connections. Since I'm putting up blocking I might as well put the conduit boxes in. They're like $1.70 a box so not exactly a huge cost.

 

[v10climber]

If you have a "man cave" area, or a corner with a TV, wire the lights in that area with their own switch. Right now, I have one light switch like you do that lights the entire 2000sf. A light over my desk and TV with a dimmer would be nice but I didn't think of it. Also, if you are going to have a workbench, provide wiring for it - I like outlets on the front of the workbench. And I have a cabinet over the workbench that needs under cabinet lighting - you might want to run that in advance.

Will you need 240 for an air compressor?

Nice looking shop, and the attic storage space is great! Whatcha gonna do in there?

Happy Motoring!

The plan is the lighting on two circuits. A "front" and "back". I think that will work just fine. I suspect most of the time I'll have all the lights on anyways. I'm going to run conduit for extra outlets so that after the building is spray foamed I can still run 240v for a compressor/lathe/mill/etc. Right now I don't have a large compressor and the big 120v compressor I have suits my needs fine. The garage will be for vehicle maintenance/restorations and I've got a small spot in the corner where a climbing wall is going up.

 

[nadogail]

Great looking garage, you might find a "how to" book at your local lumber yard or big box home store.

 

[cchamelin]

Very nice. I’d recommend either wiring two three way switches for your main lighting, with one where you have it and one switch between the overhead doors (you’ll find there’s times when you just want to open the overhead door without going into the man door) OR you can split the lighting switches out to control half the lighting with each switch. When I built and wired my detached garage, I did all the lighting with outlets vice hard wired so that I could more easily change out the light fixtures, and I’m glad I did. LED shop lights did not exist back then, but once they became relatively low cost it was a quick and easy swap out. Plus, you can get the outlets wired up now and not worry about coordinating between spray foam insulating and Sheetrock installation. Good luck!

 

[dcg9381]

Get 240V on both sides of that building. Both "ends" might be OK too. I'd have a sub panel on both sides of that garage, approximately middle. It makes things easier.

Foam insulation is going to enclose the envelope, so not the 2nd story floor. There are tons of lighting options. If you're going to recess things, you don't need blocking. If you want to hang lights, sure use 2x4 blocking. I just set regular outlet plugs (blue boxes) on the blocking where you want the lights.

Foam is excellent, but yea, you need all the exterior wall wire run now... It sounds like you all of it run now the way they inspect things there.

Unfortunately, the price of wire right now has tended with the prices of everything else.

One thing I'd consider is running conduit. I prefer PVC, but it give you some "retrofit" options that you won't have with romex in the walls. Don't have to do it of everything..

Electrical noob? You'll likely need to a ground rod or two for that separate structure.

 

[TractorJeff]

As far as Lights and Boxes. Pay the money for the Boxes! 10 years ago, pulling a wire to put up fluorescents. Now everyone wants LEDs. Point being what lighting efficiency will arise in the NEXT 10 years?

 

[Jakemedic]

Did you plan on adding ceiling fans? How about an additional one or two ceiling outlets cause you can? Great looking garage! Enjoy and by all means have fun!

 

[v10climber]

Very nice. I’d recommend either wiring two three way switches for your main lighting, with one where you have it and one switch between the overhead doors (you’ll find there’s times when you just want to open the overhead door without going into the man door) OR you can split the lighting switches out to control half the lighting with each switch. When I built and wired my detached garage, I did all the lighting with outlets vice hard wired so that I could more easily change out the light fixtures, and I’m glad I did. LED shop lights did not exist back then, but once they became relatively low cost it was a quick and easy swap out. Plus, you can get the outlets wired up now and not worry about coordinating between spray foam insulating and Sheetrock installation. Good luck!

I hadn't thought about switches between the garage doors also. If I'm entering through the garage doors then the door opener lights will be on and will allow me to get to the switches next to the man door. But being able to just reach over between the garage doors would be convenient. Even if it's just for the lighting in the "front half" of the garage.

Get 240V on both sides of that building. Both "ends" might be OK too. I'd have a sub panel on both sides of that garage, approximately middle. It makes things easier.

I have thought about 240V access. I wasn't planning on running it to the left side right now just because the boat is going to be living on the left side of the garage and I have no forseeable need for 240V over there. However, I plan on putting a number of conduit runs from the top plate down to blanked off outlets in the wall. Then once the walls are foamed in I can still run more circuits pretty easily if I need to. So another 240V circuit wouldn't be super difficult to add.

Foam insulation is going to enclose the envelope, so not the 2nd story floor. There are tons of lighting options. If you're going to recess things, you don't need blocking. If you want to hang lights, sure use 2x4 blocking. I just set regular outlet plugs (blue boxes) on the blocking where you want the lights.

I'll be spray foaming the roof decking so the upstairs area will be conditioned space. I've already got light fixtures purchased (thanks to the ultimate light fixture thread on here) and they mount directly to the ceiling. I'll probably just use those fancy Toggler bolts in the drywall once that goes up to secure the fixtures.

One thing I'd consider is running conduit. I prefer PVC, but it give you some "retrofit" options that you won't have with romex in the walls. Don't have to do it of everything..

I plan on a number of vertical conduit runs around the building in case I want to add something later. The ceiling space will all be pretty accessible so as long as I have conduit from the top plate down to the outlet I should be good. I'll definitely have some questions on the conduit runs when it gets to that point.

Electrical noob? You'll likely need to a ground rod or two for that separate structure.

I know I need 2 ground rods. At one point I had even written down what size and where but need to do more research and get that figured out for sure.

Did you plan on adding ceiling fans? How about an additional one or two ceiling outlets cause you can? Great looking garage! Enjoy and by all means have fun!

There will be 2 mini-split heads on the back wall facing the garage doors. So airflow shouldn't be an issue. I didn't have any plans for ceiling fans. I might add another ceiling outlet or two. I've got one of those retractable extension cord reels in my attached garage and it's sooo useful. Between two cord reels in the ceiling and modern cordless tools I don't envision using the wall outlets much.

 

[nadogail]

If you eliminate boxes by running your cables directly to your light fixtures you might save a little money but; I am sure you will regret that cheapness the first time you upgrade your lighting or replace a fixture.

Being cheap on your own stuff has caused a lot of regret for many.

 

[bctexas]

I plan on a number of vertical conduit runs around the building in case I want to add something later. The ceiling space will all be pretty accessible so as long as I have conduit from the top plate down to the outlet I should be good. I'll definitely have some questions on the conduit runs when it gets to that point.

This is pure speculation as I am not in the business, but how will the electrical inspector react to conduit and boxes being in place with no wiring? Will he approve what appears to him to be an incomplete wiring job when he sees empty conduit and boxes?

 

[dcg9381]

Here, we do a lot of foam insulation. Electrical inspection takes place after foam. they don't care about the romex runs in the exterior walls... Not saying that's how they do it there.

 

[MongoTA]

I'd recommend foaming, drywalling, then running surface conduit. It'll make it so much easier to modify the system down the road, especially if you're unsure of what you want now.

If you do want to wire before foaming, without a doubt walk through the space a bunch of times with a cup of coffee. Or with a beer. Or a glass of whiskey. Walk through in the morning with morning light. In the evening. At night when it's dark out. Think through your lighting, and light switch locations. Outlets. Compressed air? Welding? Spray painting? Will you need a fresh water hose bib for servicing the boat engine at all?

Anything for a security camera?

You may want exterior outlets as well.

Any need for a drop outlet coming down from the ceiling?

Envision what tasks will you do where. And what service will you need to accomplish that task.

Good luck, and enjoy the heck out of that space.

 

[v10climber]

This is pure speculation as I am not in the business, but how will the electrical inspector react to conduit and boxes being in place with no wiring? Will he approve what appears to him to be an incomplete wiring job when he sees empty conduit and boxes?

I assume this is somewhat common for places that use spray foam insulation. Since how else would you ever add new outlets/etc after the walls have been spray foamed? You have to go ahead and run empty conduit for them. But it's a good point. Between this and the comment below. Guess I need to call the county and see what they suggest.

Here, we do a lot of foam insulation. Electrical inspection takes place after foam. they don't care about the romex runs in the exterior walls... Not saying that's how they do it there.

Sunday was boating in the morning, and garage work in the afternoon/evening. Inside the garage I got 2 more sheets of OSB screwed down in the attic. That takes longer than expected since it seems to always require some trimming and fiddling to get it to land nicely on a truss.

I also spent time putting up ceiling conduit boxes for all the overhead lighting. 16 4ft fixtures in a 4x4 pattern. That took much longer than expected. Steps were basically as follows:
1. Figure out pattern and spacing of lights
2. Climb ladder, measure for first light and mark truss. Climb down big ladder (12ft ceilings).
3. Grab conduit box. Climb ladder. Nail into place. Climb down ladder.
4. Marvel at my handiwork
5. Remember the company I bought the light fixtures from (prolighting) sent me a layout to use and that conduit box is probably in the wrong spot
6. Check email. ****
7. Climb ladder. Bash conduit box until it falls off
8. Redo measurements. Realize there is already blocking where conduit box needs to be. ****. Take some measurements. Climb back down ladder
9. Redo maths again
10. Climb ladder. placing conduit box in roughly correct location
11. Move ladder. Climb ladder. Mark for next box.
12. Repeat steps 10 and 11 15 more times.

They're all up there. They're all in a line (I hope). They're just not spaced super evenly. I think the row on the left side of the garage is like 3" closer to the wall than the line on the right side of the garage. But I don't think anyone will notice.

Tonight I'll probably put up the ceiling conduit boxes for the rest of the stuff I need which is just overhead electrical outlets. And start nailing in the boxes for the wall outlets down low.

And now I'm looking at this photo realizing one of the boxes is on the wrong side of the truss. *sigh*

 

[teamextreme]

Just an FYI for when you install the lights. Everyone was hip on recommending using the boxes and suggesting that not using them was somehow not the right way to do it, but now that you are using them, you need to make sure you cut out a 4" hole in the back of the fixture to provide access to the junction box. One of the many reasons I don't do it this way when I install lights like this, additional PITA to install.

 

[v10climber]

Just an FYI for when you install the lights. Everyone was hip on recommending using the boxes and suggesting that not using them was somehow not the right way to do it, but now that you are using them, you need to make sure you cut out a 4" hole in the back of the fixture to provide access to the junction box. One of the many reasons I don't do it this way when I install lights like this, additional PITA to install.

The fixtures have a knock-out in the center. I figured that would be sufficient to get wire into the fixture? They also have a little plug that comes with the fixture. So wire the romex into the plug. Remove the knock out in the fixture. Then lift the fixture up and fish plug through knockout while securing light in place. Then plug it in.

 

[MattN03]

I had a rough in wiring inspection done on my house before I had it spray foamed. After the rough in was approved, we had it spray foamed. I completed all the wiring by installing light fixtures, electrical outlets, etc and then had a final electrical inspection done. I had to pay $70 for each inspection, but otherwise, it wasn't a big deal.

 

[v10climber]

Well I called the county. They might have been more useless than I am

Their suggestion was to submit a permit with my electrical, insulation, and drywall all as part of one application. Apparently insulation isn't inspected but drywall is? Then whoever looks over the permit will tell me the schedule of what will get inspected and when. And that will tell me what order to do things in. The person I talked to was also convinced you couldn't just run regular romex in walls and then spray foam over it. Sooooo this will be an interesting trip to the permit office and the start of quite the adventure I'm sure.

 

[dcg9381]

> The person I talked to was also convinced you couldn't just run regular romex in walls and then spray foam over it.

Ask for a code citation. I've had a ton of "no" around here when the correct answer is "we're not sure".

Every house in Texas with foam insulation has romex in the foam... Not saying that's the same for an outbuilding or in your state.

The *BEST* thing to do is catch the inspector to answer your questions.

 

[teamextreme]

The fixtures have a knock-out in the center. I figured that would be sufficient to get wire into the fixture? They also have a little plug that comes with the fixture. So wire the romex into the plug. Remove the knock out in the fixture. Then lift the fixture up and fish plug through knockout while securing light in place. Then plug it in.

You can't just run wire through the 1/2" knockout and cover the junction box with the fixture. You have to provide access to the junction box and splices.
By installing a permanent mounted fixture, which is what a strip fixture is, you've effectively covered the junction box. The 1/2" knockout is for bringing in conduit, or romex if you're not using junction boxes.

 

[pattenp]

You can't just run wire through the 1/2" knockout and cover the junction box with the fixture. You have to provide access to the junction box and splices.
By installing a permanent mounted fixture, which is what a strip fixture is, you've effectively covered the junction box. The 1/2" knockout is for bringing in conduit, or romex if you're not using junction boxes.

Fixtures are mounted over ceiling outlet boxes all the time where the fixture needs to be removed to access the wiring.

 

[teamextreme]

Fixtures are mounted over ceiling outlet boxes all the time where the fixture needs to be removed to access the wiring.

Sure, but strip fixtures are considered to be permanent mounted, not like a box-mounted fixture you can easily take down. When I was in the trade I was always taught it's a code violation to cover with a strip fixture.

 

[v10climber]

This is the fixture I bought. Just so everyone is on the same page.

https://www.prolighting.com/t443ssubcxx00p0-18w5k.html

I did some more work earlier this week. Have pretty much all of the electrical boxes in place except for the exterior ones which will be a bunch more work. Have to cut out the siding and all that. Is there any particular trick to placing exterior outlets? Place the box where I want it from the inside. Drill some holes and connect them with the jigsaw. Then nail the conduit box in place? Seems like that is what was done with the exterior outlets on my house. But those were put in 30 years ago.

 

[pattenp]

Sure, but strip fixtures are considered to be permanent mounted, not like a box-mounted fixture you can easily take down. When I was in the trade I was always taught it's a code violation to cover with a strip fixture.

Not where I am. I'm not seeing any NEC violation for having a strip fixture mounted over a ceiling box. I believe in the 2020 NEC it was added that the only lighting fixture not allowed to be used for access to a box is recessed lighting fixtures unless the box is a part of the recessed fixture.

 

[Terry D]

Strip fixtures that are designed to mount on a box usually have a large knock out so the splices can be accessed from inside the fixure. It will also have the slots for the 8/32 screws. The 1/2" knockouts on a strip fixture are to connect a raceway or a cable assembly to it, so the splices will be with in the fixture

Try looking at 410.24(B)

Sent from my SM-G960U using The Garage Journal mobile app

 

[pattenp]

Strip fixtures that are designed to mount on a box usually have a large knock out so the splices can be accessed from inside the fixure. It will also have the slots for the 8/32 screws. The 1/2" knockouts on a strip fixture are to connect a raceway or a cable assembly to it, so the splices will be with in the fixture

Try looking at 410.24(B)

Sent from my SM-G960U using The Garage Journal mobile app

I see what you are saying and read 410.24(b) and agree. It appears that's one of those code things not adhered to around here. I've seen quite a bit of nm from a box pulled through a button clamp in a small knockout on strip fixtures that's mounted over a ceiling box.

 

[Terry D]

I see what you are saying and read 410.24(b) and agree. It appears that's one of those code things not adhered to around here. I've seen quite a bit of nm from a box pulled through a button clamp in a small knockout on strip fixtures that's mounted over a ceiling box.

I've seen it done also, hell, I probably have done it

 

[v10climber]

I've been making progress. Went and submitted the permit info earlier this week. So waiting for the county to get back to me on that. However, I've got all the interior conduit boxes nailed in place. I've run romex between a bunch of them. Picked up my circuit breaker panel so I can mount that and start running home runs. Heading out later today to get another 250ft spool of 14/2 and then some 10/2 for A/C and lift circuits.

The question I have is related to the exterior electrical outlets and light fixtures. The garage is stick built with hardiboard siding. I've watched tons of videos. I've read articles. I can't seem to figure out what to do about conduit boxes. Do I cut a hole in the wall, nail a standard 1 gang conduit box to the stud on the inside of the building. Then use long screws to secure a cover like the link below?

https://www.lowes.com/pd/TayMac-1-Gang-Rectangle-Plastic-Weatherproof-Electrical-Box-Cover/50372928

Alternately, do I cut a hole for the conduit box and insert it from the outside of the building. Securing it using the flange on an old work box or something to the building. Then install the cover?

Same question for the round light fixture conduit boxes I guess. This really doesn't seem like it should be hard to figure out but here I am. Thanks!

 

[v10climber]

And since everyone around here like pictures. It's now painted. I've pulled relocated part of the chain link fence that was in front of it enclosing the backyard. Since this photo I've removed all the leftover fence posts. Still have to put some new fence up after the driveway gets ripped up and pavers go down. I've got a few large things inside (2 cars and 1 boat) and it's awesome having some place to put stuff out of the weather. Really looking forward to getting it fully operational!

 

[vdotmatrix]

Draw up plans, pull a permit… if permitted in your area, but do the work yourself.
They will correct the plans if faulty, they will inspect your work and keep you from burning something to the ground.

If you are that much of a noob and are not comfortable with electricity , effin do not try it…hire someone to do it.

 

[alfredeneuman]

The fixtures have a knock-out in the center. I figured that would be sufficient to get wire into the fixture?

You must have access to the box without removing the fixture. If it's a 1/2" (7/8" hole) KO, it wouldn't do.

 

[Norcal]

I have punched a 2" (conduit size) knockout & popped in a plastic bushing to protect the wiring from chaffing, not going to work on a narrow width fixture though, but they won't cover a normal box either, that is when stubbing out the Romex® works best, which is quick,cheap, and effective.

 

[alfredeneuman]

I have punched a 2" (conduit size) knockout & popped in a plastic bushing to protect the wiring from chaffing, not going to work on a narrow width fixture though,

I've done it before by putting the die outside, the cutter inside, stretching the fixture a out a little bit and bending it back after I'm done.