# Building shop extension on garage, advice on electric, etc



## bobspryn (Dec 5, 2017)

Hey All!

Relatively new woodworker, currently building an extension onto my garage to accommodate my wood shop. The extension adds 18×12' to my current garage, and my working space will extend 6-10' into my garage, giving me a total workspace of about 18×20 or so. Right now the bump out is under construction, and I'm looking for advice on construction related issues like electricity.

I am figuring on having a sub panel put in (our house breaker is 200A, so a sub panel seem sufficient), and running banks of LED task lighting above. The outlets are one of my primary questions. In the wall or in conduit? I was figuring on in the wall, but a few folks have suggested doing conduit instead so I can move them at a later time easier. Of course I could add new runs from the sub panel at a later date as well I guess.

I've modeled up the area in sketchup, and thrown in my table saw, along with approximations of other tools and furniture. All subject to change in layout. (I'll look for layout advice at some point too, but I'm figuring on just lighting the whole area well enough that I don't need to worry about light placement in the small space.)

Look forward to contributing to this forum!

Bob


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## MrRon (Jul 9, 2009)

So far it looks like you have everything covered. I would use conduit for the ease of adding/moving outlets. I would place the outlets 48" above the floor. Actual tool placement will be determined upon actual work flow. I would move the workbench over to the wall with the window. What appears to be a raised floor is a waste of space. That is a prime candidate for a fixed item such as a workbench. Keep us posted on your progress. We can all learn something from these "exercises".


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## clin (Sep 3, 2015)

I'd keep the wiring in the wall, and add lots of outlets and circuits. It's relatively easy and cheap to do with new construction. So why not?

EDIT: I should have added by being in the walls, that leaves the walls clear for cabinets and other things you'd want to hang on the walls.

When I did mine, I ran outlets high (above workbench height) and low (below workbench height). I also spaced them about 4 ft apart.

Something I read, though after I put mine in, was to put the high ones above 4 ft. That way if you lay sheet goods against the wall, you won't cover the outlet. Seems like a good idea to me.

Even if in the walls, you can always transition to conduit if you need to add something later.

Keeping to code of course, but there is no such thing as too many outlets. Don't forget to throw some 240 V ones around as well. Some in the ceiling also. You might want to add fans or an air filter to the ceiling or of course drop down to a machine.

I'm also a believer in you can't have too much light. My shop is small (~300 sq ft), so I just have a lot of overall light. Nice thing about that is almost no shadows.

Your shop is not that much larger. So consider just a lot of overall light. Though consider having banks of lights so you don't have to have them all on when not needed. While LED lights are efficient, with enough of them they still use real power and put out heat. So you can easily still have several hundred watts of power going to lights. That''s like having a small space heater running all the time.

Also, don't forget about AC and heating. Even if you have no plans to do it now, factor that into your sub-panel and stub out as necessary to make it easy to add later.

Same for a dust collector. Maybe you have no plans for one or a large one now, but assume you want to put a big-boy 5 HP DC in some day. Again, much easier to put a circuit in now.


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## bobspryn (Dec 5, 2017)

Great help!

That does look like a raised floor, but it isn't. Didn't see that until now. That is just because it's showing my original plan where I was only bumping out 8' before realizing that was too small, so the old exterior wall.

I think I will go in-wall for now, with the plan on being able to add conduit later if necessary.

> When I did mine, I ran outlets high (above workbench height) and low (below workbench height). I also spaced them about 4 ft apart.

Both high and low every 4'? Same circuits or different? How did you determine which outlets to put on different circuits btw? I read about doing some sort of triple wire thing to an outlet so you can have multiple circuits at the same spot, but that it was also "dangerous", at least if you were adding it yourself. Did you do double or quad outlets? How many 240s did you add on the wall?

I definitely was thinking of some outlets above hanging down, but wasn't thinking 240 originally. I supposed that makes sense, as I was thinking that an "island" of power tools makes most efficient use of space, and would prefer to drop a line down to that instead of running across the floor. Maybe multiple circuits in that one spot, and a 240 by the window where a ductless unit might go in the future. Although only half the garage will have insulation, so I might need to solve that before trying to heat/cool it with a unit like that.

Lots of light is exactly what I was planning. Any advice on particular LED units?

Super helpful. Thanks everyone!


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## MrRon (Jul 9, 2009)

In my shop, I added outlets on the front edge of the bench, not the back. That keeps the cord out of the way and not draped across the work or bench; especially true if the bench is very deep; >30".


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## d38 (Sep 6, 2017)

I built a new 30×44 garage 5 years ago. In the work area (~15×30), one breaker per 2 outlets. The rest is one breaker per 3 outlets. Outlets are every 3rd stud. 
I had to add a 240v this fall for my 2 hp DC. So yes, think about where that might sit some day, and run 10ga wire to it to give you more hp options. Same for table saw-have 110 and 240v available. 
I'm in SD and have 3 ceiling fans, plus a box to add a 4th if I feel the need. Nice to circulate air in hot summer or keep the furnace air off the 10' ceiling.
I'd go in wall on the new walls. But mount the panel exposed on the wall so you have access to the sides for adding conduit runs later. 
No such thing as a shop too big, or too much electricity available. And its way cheaper the first time. So make a plan, add 50% or more, and you should be good.


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## jonah (May 15, 2009)

I'm a big fan of the Costco LED shop lights. They're $20 for a 4' unit, and they're the perfect color temperature for me (4000K). They also have an unlimited return policy, like most Costco items. You can daisy-chain them together if need be. It won't be as clean a look as if you get real ceiling fixtures, but they're great.


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## clin (Sep 3, 2015)

> > When I did mine, I ran outlets high (above workbench height) and low (below workbench height). I also spaced them about 4 ft apart.
> 
> Both high and low every 4 ? Same circuits or different? How did you determine which outlets to put on different circuits btw? I read about doing some sort of triple wire thing to an outlet so you can have multiple circuits at the same spot, but that it was also "dangerous", at least if you were adding it yourself. Did you do double or quad outlets? How many 240s did you add on the wall?
> 
> - bobspryn


Yes, high sockets at 4 feet apart and low at 4 feet apart. In my case I was only building in one new wall to separate a 3rd garage bay for my shop. I ran the top sockets as a circuit and the bottom as a circuit. There is some sort of code limit on the number of sockets per circuits. I also put a GFI as the first socket on each circuit.

I didn't do anything odd. Given all the expense to build out something, more wire and sockets is pretty trivial.

FYI, while it sort of read that way, I was just generally saying to put some sockets in the ceiling, not specifically 240 V. Though you never know what you might need.

Of course you don't want to go crazy. Just add what seems like you might use some day. Make some provisions to add things more easily in the future. For example, if you have an attic space, you could run some conduit from your sub-panel to the attic that would make it much easier to pull more wire form the sub-panel to the attic in the future. Though I have no idea what code says about such things. I.E., is it okay to run conduit from a panel to nowhere in particular with no wire in it?

Concerning heat and cooling, insulate everything now. Even without added heating or cooling, insulation will keep it more comfortable. And if well insulated, it is much easier to heat and cool later. In my case I had a mini-split unit put in and just love having a space that can be whatever temperature I want it to be.

I also replace my overhead garage door with two large swinging doors that are pretty much the equivalent of R13 walls. With all sorts of weather sealing.

For lighting, I used 4 ft T8 florescent lights. LEDs were not quite there at the time I built and I'm not sure they are yet. T8's are almost as efficient as LEDs and more so in some cases. I know people like LEDs, but I don't get the sense that they have standardized yet.

No doubt LEDs are the future of lighting. Obviously fluorescent tubes fail pretty often, and the LEDs themselves will likely last for decades if not centuries. But there's some electronics in them that could go bad depending on how well it is built. Same is true of course for a fluorescent ballast. But, I can go out and buy a replacement ballast. As far as I know, if an LED fixture craps out (and it will be the power supply), you'd just have to but a new fixture.


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## TajBuilder (Aug 6, 2008)

I recently had a ballast and both tubes go bad on a double eight foot T12 fixture and replaced it with two eight foot LED's for about the same price as a new ballast and two T12 tubes. Great lights and easy to change using the same fixture and tombstones. Simply bypass the ballast with the neutral going to one end and the hot going to the other. I have fourteen more eight foot lights in my shop that I'll be replacing with LED's as they burn out.

You may also want to consider running 4" PVC for future dust collection and conduit for your table saw before you pour your concrete.


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## TajBuilder (Aug 6, 2008)

> I also replace my overhead garage door with two large swinging doors that are pretty much the equivalent of R13 walls. With all sorts of weather sealing.
> 
> - clin


What are the dimensions of your doors? I'm thinking about doing the same thing.


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## jonah (May 15, 2009)

You'd be foolish to not use LEDs for lighting, considering they cost the same, are more efficient, and last many times as long as fluorescent fixtures.


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## wapakfred (Jul 29, 2011)

I've just built a new shop and used those Costco lamps Jonah mentioned…I could n't be happier. There's nothing to say they won't crash on the same day in a year or 2, but right I'm a happy camper. As for the outlets, I like mine in the wall…and like Clin said, put in plenty and you won't have to move anything. Keep them 50" or so from the floor and you're good to go. I also use a lot of ceiling outlets, I like the twist lock outlets there (for the tools, the lamps on on their own flat stab outlets, and a dedicated ciruit) and more or less centered them in the room.


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## richardchaos (May 12, 2017)

1) YES by any and all mean use LEDs for lighting…
2) Put everything on wheels. Even your wife and/or GF
3) Put 4 gang outlets every 4 feet.
4) Dedicated circuits for Everything that uses 13 am or more. Table saw, compressor, router etc.
5) ALSO I have extra GANGED LEDs shop lights right above my table saw.router. and plan on the same over my chop saw and assembly table.

ALSO I put in two gable vent at both ends of the ceiling before I sealed it up with insulation and drywall. I also ran a 20 amp circuit for a window AC unit come summer and made a place in the framing for same


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## richardchaos (May 12, 2017)

AS far as the BIG door I kept my typical roll up garage door but put 1/2 inch styrofoam board over it and 2 layers of clear bubble wrap over the windows. I like that cause it lets light in but no one can see whats inside


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## Jacksdad (Mar 28, 2017)

If you run wiring in the wall you don't need conduit. For lights I can't stand florescent light so my 26×26 shop I ran 16 65 watt recessed cans and i have 2 cans added by the lathe. I like them much better, this was before the led lights came out so I'm thinking of adding them as task lighting. I also built an addition off my shop that's 12×6 for dust collector and air compressor which I don't have out there but when I do it will be awesome. I ran a 1/2" copper pipe in the concrete for the air compressor drain. I also have 200 amp service in the house and I ran a 100 amp subpanel in the shop which is great, put the lights on a separate circuit than the outlets.


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## Hermit (Oct 9, 2014)

Here's what I did not long ago..

1. 20 amp circuits, each wall on it's own circuit.
2. Lighting on it's own circuit.
3. Dust collector, air compressor on it's own circuit
4. Through wall heat/ac on it's own circuit
5. Future 220 volt wiring to 2 boxes with blank cover plates.
6. All led lighting
7. 20 amp plugs every 4 feet around the shop
8. Ceiling plugs for air cleaners and pull down 20amp extension cords..
9. Pre ran speaker wires and tv cable.


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## Holbs (Nov 4, 2012)

http://lumberjocks.com/Holbs/blog/34833 My happy journey of doing the same thing you are attempting.
I put romex in the wall studs so that I would not have conduit in the way of stuff. 
I put enough outlets (110v and 220v) not to worry about adding anything down the road.
Heavily stress adding 2 different overhead circuits for 2 extension reels. They seem to be my #1 used outlets for everything.
Also, heavily stress having 2 zone lighting on 2 different circuits. I have the original single light bulb always on that is only tied into the house circuits. All my T8's are one the garage circuits. If for some reason the light breaker pops in the middle of a table saw cut, I have that single light bulb as insurance.


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## sawdustdad (Dec 23, 2015)

> Here s what I did not long ago..
> 
> 1. 20 amp circuits, each wall on it s own circuit.
> 2. Lighting on it s own circuit.
> ...


Good advice, did pretty much the same thing in my recent shop build. I have six or seven 240v circuits. I went with fluorescent lights as they were much less expensive and nearly as efficient as LED.


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## msinc (Jan 8, 2017)

I didn't use conduit with the idea I would move it. My thought is I don't move anything, I run a new one. That said, make sure you have a big enough sub panel to add things in the future. The other thing I would suggest is a couple of 4 gang ceiling drop downs. These come in handy when you are working out in the middle of the floor and don't want cords in the way. I would suggest you do not go for those auto wind up cord reels…they are pretty expensive for good ones and the cheap ones are junk.


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## bobspryn (Dec 5, 2017)

Man. All fantastic advice. I'm going to draw it up on a plan here and maybe run it by you guys.

If I have an island of power tools that I have wires coming down from the ceiling for (to avoid running across the floor), I probably need to have multiple circuits no? Actually, I guess I would only be using one of those at a time.

Thanks folks!


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## jonah (May 15, 2009)

> Good advice, did pretty much the same thing in my recent shop build. I have six or seven 240v circuits. I went with fluorescent lights as they were much less expensive and nearly as efficient as LED.
> 
> - sawdustdad


That may have been true five years ago, but today LED fixtures are equivalent to or cheaper than fluorescent. They are a bit more efficient, produce less heat, are more reliable, last longer, and don't require ballast/bulb replacements a couple of years down the road. They also work in a much wider range of temperatures, come on at full brightness immediately, and don't require special disposal of the bulbs. There is basically no reason to use fluorescent anymore for 95% of use cases.


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## bobspryn (Dec 5, 2017)

Definitely going LED. No question. Debating having some pro's come out and put the lights in vs just buying some units and having the electrician do it. Want quality lights that will last ages.


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## clin (Sep 3, 2015)

> I also replace my overhead garage door with two large swinging doors that are pretty much the equivalent of R13 walls. With all sorts of weather sealing.
> 
> - clin
> 
> ...


I literally took the single garage door and cut it in half. So each door is something like 7 ft tall by 4 ft wide. I had a steel frame made for each door. I set the original (cut in half) door panels in the frame. Suitably caulked. Fit 1.5" mahogany frame inside that screwed to both the steel frame on the edge of the door and to the panels now trapped between the steel frame and wood frame.

I added some additional 1x wood webs, some blocking to support doors bolts and a handle, and fit 1.5" thick foam board insulation. The white area seen below is the back side of the original garage door panels. After the insulation I put on 1/4" plywood. Even before the plywood there was zero sag. The way the garage panels were secured and the steel frame it came out very true.










The whole point of this was so the outside wouldn't look weird and it works well. I just push it open from the inside and have no exterior latch or even a handle. Though I do occasionally block it open if I'm coming and going.

I have vinyl covered foam (kerf) weather stripping on the inside, like most modern doors use, as well as the stuff on the sides that is folded and fills the gaps. Between the 1.5" of foam in the garage panels, and the foam I added, it is very well insulated for a door. Effectively about the same as a 4" thick wall.


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## wapakfred (Jul 29, 2011)

> Man. All fantastic advice. I m going to draw it up on a plan here and maybe run it by you guys.
> 
> If I have an island of power tools that I have wires coming down from the ceiling for (to avoid running across the floor), I probably need to have multiple circuits no? Actually, I guess I would only be using one of those at a time.
> 
> ...


You would want multiple circuits to suit your needs, I have 120V/20A, 240V/20A, and 240V/30A in my ceiling since I need all three…but the 120V is just one duplex.


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## Redoak49 (Dec 15, 2012)

You might want to think about how you get Wifi and maybe Cable.

Take pictures of your walls before drywall to have a record of where the wiring is in the wall. Also, document wire sizes. All of this makes changes in the future easier.


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## bobspryn (Dec 5, 2017)

Here's an initial stab at wiring. Walkthrough is Friday. I didn't call out circuits, other than going with the idea of having each outlet have two circuits run to it so I could plug in a power tool and dust collection (shop vac) right there.

Please share thoughts!










Framing is complete!!


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## Blackie_ (Jul 10, 2011)

I'd like to touch on Clin's LED lighting, I just refitted my entire shop replacing all of my fluorescent light fixtures in which lowered my ceiling with flush mounted 6" LED lighting that raised my ceiling and not feeling any heat from the fixtures what so ever aside that they do save on electricity. I have two banks 670 lumination 65 watt total of 11 recessed fixtures split into two banks =715 watts in my 12' x 24' shop which gives me plenty of lighting without any noticeable heat.

Make sure your wiring to the panel is large enough to supply the amperage and wouldn't hurt to go over board a step either.


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