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rewiring garage, questions about conduit pros and cons

13850 Views 32 Replies 12 Participants Last post by  frenchelectrican
inside of my garage is exposed studs. no sheathing, just clapboard over studs.

i'm bringing in a new 40 amp sub panel, and running three outlet circuits and 2-3 light circuits.

this is my work shop, running mainly basic power pools, but also a dedicated lathe bench. table saw is highest amperage.

trying to figure out the best way to wire this. is 3/4" galv. conduit overkill and/or unnecessary? i think it would look nice, but it would require mounting the boxes on the outside edge of the studs.

if not conduit, i need to drill out all the studs, which is annoying, and either have exposed wiring really close to my work benches, or have the main feeds at the top plate, and drop down to each outlet, but this would mean a bunch of junction boxes at the top, adding time and money.

do you guys have any perspective as far as code? i am allowed to use the conduit? is it a stupid idea for other reasons?

how would you guys personally wire this job if it were your garage?

thanks a lot,
B
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I would run romex in the walls and use plastic boxes but you will still need to drill out the studs. Doing it this way will allow you or if you sell it someone else could cover the walls with drywall at a later date. Yea I think it's over kill to use galvi. Plan your project you should not have a bunch of j-boxes in the attic area.
I'm not an expert, so wait for the pros here to chime in on the exact code requirements. But all interior wiring must be covered or protected from physical damage, electrical in an unfinished garage or electrical stapled to any exterior surface is against code. Which means if you plan on not finishing the garage it has to be in conduit, keep in mind the conduit has to be properly grounded if you use metal.


I don't know if the same applies if you use armored cable or not.

The downside of conduit is you may (or may not) have to get a pipe bender to make bends in the conduit, you'll have to get a thousand little joints and elbows and brackets, then you'll need to get a nylon fishtape and probably some lube to get the cable through the conduit without damaging it.

If it was my garage, i would drill the holes, run the cable properly and drywall and finish the garage. I'd also throw in some insulation on the exterior walls. But that's just me, everything has to be perfect.
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inside of my garage is exposed studs. no sheathing, just clapboard over studs.

i'm bringing in a new 40 amp sub panel, and running three outlet circuits and 2-3 light circuits.

this is my work shop, running mainly basic power pools, but also a dedicated lathe bench. table saw is highest amperage.

trying to figure out the best way to wire this. is 3/4" galv. conduit overkill and/or unnecessary? i think it would look nice, but it would require mounting the boxes on the outside edge of the studs.

if not conduit, i need to drill out all the studs, which is annoying, and either have exposed wiring really close to my work benches, or have the main feeds at the top plate, and drop down to each outlet, but this would mean a bunch of junction boxes at the top, adding time and money.

do you guys have any perspective as far as code? i am allowed to use the conduit? is it a stupid idea for other reasons?

how would you guys personally wire this job if it were your garage?

thanks a lot,
B
I'd probably use ENT (Smurf) for areas that might need physical protection and romex everywhere else.
I'd probably use ENT (Smurf) for areas that might need physical protection and romex everywhere else.
Pfffffftt.... In that case you could just wet the romex. I mean, the water will provide about as much physical protection as the smurf, and water is much cheaper....
I'll be wiring my garage shortly - no conduit
I'll be running the wire in the stud bays
Eventually I will insulate & instead of drywall I'll be using OSB in a lot of areas
I like to be able to put a screw in to hold things up

But all interior wiring must be covered or protected from physical damage, electrical in an unfinished garage or electrical stapled to any exterior surface is against code.
Interior wiring in a stud bay is protected
Unfinished basements have exposed wires in stud bays all the time
You could run the wire up higher & only drop down to the boxes in a stud bay
But I prefer the wire in the walls
... instead of drywall I'll be using OSB in a lot of areas
I like to be able to put a screw in to hold things up

Not a bad idea, but if this is an attached garage, by code your house side wall must be drywall or another material rated for a 15 min burn time. I don't believe there is any restriction on any other walls though.
Good point - the house wall side will have 5/8" sheetrock
There will be stairs to the basement on that side - nothing "hanging"
I think the OSB also gives better protection - IE it won't get a hole punched in it as easily as sheetrock
Good point - the house wall side will have 5/8" sheetrock
There will be stairs to the basement on that side - nothing "hanging"
I think the OSB also gives better protection - IE it won't get a hole punched in it as easily as sheetrock
I would agree with the better protection, but it tends to burn faster than Sheetrock does, haha. My garage is the same in that the house side wall is Sheetrock with a set of stairs into the basement; the other walls and ceiling are un-covered at this point. Eventually I will put up 3/4" plywood on the ceiling to make a decent storage space out of the garage rafters, and at some point a 40 amp sub panel for garage outlets and tools and such.

Normally I'd run conduit into the garage for the feeder and run individual conductors, but I have a length of 6/4 aluminum I got for cheap that I'd like to make some use of. Sub panel in the garage doesn't need to be much, and changing it later wouldn't be that difficult either.
thanks a lot everyone, for the replies.
i'll drill out the studs.

last question: since i just have clapboard on the outside, if i'm running my wiring horizontally from box to box, there's really nowhere to staple the wire to... even harder if i have the wire higher than the boxes and drop down to each outlet.

can i just take up the slack and let it sit there?

thanks.
Normally you staple the wire to the sides of the studs. I am not familiar with this clap board, but drilling holes through the studs horizontally is considered sufficient securing of the cable, just so long as you staple the wire before it enters the box. I would imagine you have enough room to nail a box in place on the stud, so you should have enough room to staple the wire there too....
How far apart are the studs?
Don't nail to the clapboard
The wire just "hangs" between the studs
It shouldn't be sagging too much
As you go down to the biox staple the wire to the side of the stud



clapboards - also called lap siding

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2
As far as electricial codes go for a garage this is what I think. If you are having your job inspected you can call the building department and speak with an inspector. Codes may be different where you live. But here on the west coast this is what I have found.
1-all recepticals to be on a GFI circuit Except dedicated single receptical outlets.
2-wiring in the walls without emt, ect. is ok since this is not a living area.
3-the only thing I have had an inspector tell me "once" was he wanted to see the wires that went across the trusses nailed to a board nailed to the trusses. I did it just to please him, but have never done it before or since.
As far as electricial codes go for a garage this is what I think. If you are having your job inspected you can call the building department and speak with an inspector. Codes may be different where you live. But here on the west coast this is what I have found.
1-all recepticals to be on a GFI circuit Except dedicated single receptical outlets.
2-wiring in the walls without emt, ect. is ok since this is not a living area.
3-the only thing I have had an inspector tell me "once" was he wanted to see the wires that went across the trusses nailed to a board nailed to the trusses. I did it just to please him, but have never done it before or since.
thanks man. yeah, this GFI thing seems a bit absurd to me, considering what's been there has been a single 15amp circuit fuse for ONE outlet, and ONE light, with knob and tube wiring, stapled to the inside edge of the studs.

questions: rather than having the first outlet on each circuit be GFI, can i do a GFI circuit breaker instead?

thanks again.
I really would like to say why don't you get a peace of 2x4 and nail it from stud to stud, Their you can align the romex in order and bring it all in the panel as they have provided you with 1/2 3/4 and 1" K/O seal. You really need to follow the code here are some ref to the code.376.30 / 225.10 you will find these in the code book
thanks man. yeah, this GFI thing seems a bit absurd to me, considering what's been there has been a single 15amp circuit fuse for ONE outlet, and ONE light, with knob and tube wiring, stapled to the inside edge of the studs.

questions: rather than having the first outlet on each circuit be GFI, can i do a GFI circuit breaker instead?

thanks again.
My 2 cents- Yes you can use a GFCI breaker but if the (sub)panel is not in the garage (or close by), it can be much less convenient when it pops; a GFI in the first position of a garage circuit seems easier (and cheaper) to me for a reset.

In my garage (previously drywall finished and insulated) I have predominately used romex with EMT using surface mounted boxes where exposed for physical damage. I also have AC/MC where connecting boxes on both pillars of a 16' garage door. I like using nice, solid connection boxes mounded well to studs as too often my tool plugs have a way of loosening the boxes installed in drywall. :yes:
Schmolze, Yes, GFCI breaker is acceptable and cheaper to your wallet. But remember the recpt. must be identified as a GFCI at all location when using a breaker typ. And I really suggest that no matter what you are wiring or thinking about doing it, do the raceway, install the conduit get away from the romex. and always us a 3/4 or higher. You may what to add other circuit later.
Since Tom Silva is working on the garage I would have thought he would have brought the whole Ask This Old House crew.:thumbsup:
Even with 1/2" EMT you still have plenty of room if you needed to add additional circuits.
Even with 1/2" EMT you still have plenty of room if you needed to add additional circuits.
i'm confused, so now you guys are saying DO use the conduit? this would be installed on the inside face of the room...

thanks.
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