Hanging EMT conduit in new shop.

[Michael Gantz]

I'm currently in the process of building a 24' x 36' shop with 10' ceilings. The walls are 2" x 6" studs and the cavities are filled with cellulose insulation. The walls are covered in 1/2" drywall. My intention is to minimize wall penetrations to keep air leaks to a minimum.

The plan is to place a 100 amp sub-panel on a wall in the shop to provide power. Power will be distributed via EMT conduit. I'm planning on going this route because I believe it to be a much easier system to modify in the long run, as opposed to placing the wiring in the walls. I'm thinking of mounting 2' vertical sections of uni strut on the top of the walls every 64" mounted to studs. This gives me mounting options for the EMT plus other items like compressed air distribution.

In the past I've just mounted stuff to the drywall, but that wasn't always easy. Sometimes the drywall compresses under a clamp. Sometimes you need a stud for something heavier, etc. I'm thinking the uni-strut might make things a bit easier as there is less fighting and fidgeting with the mounting system.

Has anybody done this in their shop? If you did, do you believe it was worth the effort? Has anybody done it and regretted it?

[Andrew Seemann]

I haven't tried unistrut, but I did do one shop in Romex and one in surface mounted EMT. I wouldn't consider using Romex again after using surface mount EMT. Much easier to modify and add-on to the EMT.

[Darcy Warner]

I love unistrut. adult erector sets.

[Paul F Franklin]

I've not used unistrut in the way you describe, but have used it to mount a lot of other stuff, including pegboard. I think it would make for solid, neat installation. One tip for cutting it: if you don't have a hand held bandsaw, or another way to cut it, invest in the harbor freight model. A little over $100 with the usual coupon and cuts it like butter with very little burr. Also great for cutting the emt itself.

In my experience, having a run of 1" or bigger emt with lots of boxes in line is the easiest way to a flexible installation. You can run a couple of general purpose circuits and still have plenty of conduit fill left over for future needs. Use big boxes or you run into box fill limitations though.

[Tom Dixon]

When I built my 24'x36' shop a couple years ago I had the electrician install all 2 3/4 conduit from each 4" square deep box up to the attic so I could fish new wiring if I had to change a circuit later. He ran romex to the conduit all above the ceiling in the attic. This was all done before the drywall. Whether it is internal or external to the drywall I suggest running double the conduit so you can easily make changes later.

[Tim Janssen]

Since you are still building and nothing to do with electrical, but paint walls and ceilings white. You'll be surprised how little if any you will be bothered by shadows.
Just a tip.
Nice size shop. About 3 times the size of my basement shop.

Tim

[Frank Pratt]

Check your local electrical code. Here 1/2" EMT must be supported at least every 60". But I think your idea is a great one.

[Kevin Goss]

I like a strut rack. A few things to consider, get pricing for 3/4 pipe and wire from your local electrical supply house and the big box store, they're can be significant price differences, for me pipe is cheaper at lowes with the bulk price than the supply house. It actually is $2 per stick cheaper. Wire in 500' spools is cheaper at the supply house, as is all the pipe fittings like couplings, strut straps, spring nuts, and bolts. Metal boxes are 1/3 the price at the supply house. Send them a material list and ask for a full quote. 3/4 pipe is easy to work with and way nicer to pull wire in than 1/2". I don't know if this applies to you but there's 7/8 strut and 1 5/8 strut. 3/4 pipe is 1 1/8" so imo for a nicer looking install that pipes and things running 90* to the rack can run under your pipe rack with 1 5/8 strut. 7/8 strut is nice by the panel so you don't have to offset as much going into the panel. Then transition to 1 5/8 on the ceiling. The other reasoning is if you had a pipe in between pipes or the opposite side of the rack, with 7/8 strut you would need to kick a 90 down over the other pipes and offset back up to the ceiling. With 1 5/8 stut you just kick it up to the ceiling and you're under the pipes and it looks cleaner with less offsets.

[Robert Engel]

I've got most of my shop in conduit. Thats a nice commercial level system, but you can get by without it not that much hassle.

Crossrun, you can screw into joist or stud, parallel you can use drywall anchors.

[Michael Gantz]

Tim,

Yes, I've learned this lesson several times over. As a matter of fact I actually went overboard once and did "glossy white"! Ever been in a shop that required sun glasses? I owned one, uggggh. I'll probably do the walls in white and then do the ceiling in white with a very small touch of blue for a more natural color.

Michael

ETA: I went with glossy because I thought it would be easy to clean. I didn't realize the full impact of being inside a glossy cube.



Since you are still building and nothing to do with electrical, but paint walls and ceilings white. You'll be surprised how little if any you will be bothered by shadows.
Just a tip.
Nice size shop. About 3 times the size of my basement shop.

Tim

[Michael Gantz]

Code should get interesting. This is a detached work shop. The local inspector tells me it gets categorized as an "agricultural building". He, obviously, was really concerned about the footing depths and framing. But after that didn't seem concerned. I'm guessing there's a lot more freedom in what is essentially considered a barn.


Check your local electrical code. Here 1/2" EMT must be supported at least every 60". But I think your idea is a great one.

[Michael Gantz]

I don't know if this applies to you but there's 7/8 strut and 1 5/8 strut. 3/4 pipe is 1 1/8" so imo for a nicer looking install that pipes and things running 90* to the rack can run under your pipe rack with 1 5/8 strut. 7/8 strut is nice by the panel so you don't have to offset as much going into the panel. Then transition to 1 5/8 on the ceiling. The other reasoning is if you had a pipe in between pipes or the opposite side of the rack, with 7/8 strut you would need to kick a 90 down over the other pipes and offset back up to the ceiling. With 1 5/8 stut you just kick it up to the ceiling and you're under the pipes and it looks cleaner with less offsets.

Now this is gold right here. I probably wouldn't have even thought about it and just went with 7/8. I hadn't worked out in my head how to make some of those transitions and just though I'd figure it out when I ran into the problem. Going with 1 5/8 solves that problem very conveniently. I think you may have just saved me from a bunch of disappointment.

[Jim Becker]

If your local code permits it, the grey plastic conduit is a lot easier to work with than the metallic. You do need to run separate grounds, however.

I agree with the benefits of the surface mounted conduit because of the flexibility over time. While I initially wired my shop with wire in the walls, etc., pretty much all subsequent work was done using conduit. Should I ever move and setup a new shop, that lesson will follow me.

[Kevin Goss]

No problem, the only thing to be aware of is when kicking a 90 to get out of the rack you need enough space between conduits to clear the radius of the 90. so for instance you're kicking up 1 5/8' to the ceiling you may need 1 1/2" or more spacing between conduits to allow the radius of the 90 since 1 5/8" kick isn't that big of a kick. i may not be a great woodworker contributor but i love conduit

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[Michael Gantz]

Gotta admit, I'm a bit jealous of some of those bends!


i may not be a great woodworker contributor but i love conduit

[Michael Gantz]

Jim,

I've never used grey plastic indoors. Can that stuff be heated and bent? Or does everything need to be done with fittings? I like the ability to put multiple and compound bends into EMT. Gives it a really clean look without all the fittings.

Michael


If your local code permits it, the grey plastic conduit is a lot easier to work with than the metallic.

[Frank Pratt]

If your local code permits it, the grey plastic conduit is a lot easier to work with than the metallic. You do need to run separate grounds, however.

I agree with the benefits of the surface mounted conduit because of the flexibility over time. While I initially wired my shop with wire in the walls, etc., pretty much all subsequent work was done using conduit. Should I ever move and setup a new shop, that lesson will follow me.

But Jim, EMT is so much prettier. I love doing conduit work & I get almost as much satisfaction out of building a beautifully done rack of EMT as I do out of a piece of furniture.

[Rod Sheridan]

Jim,

I've never used grey plastic indoors. Can that stuff be heated and bent? Or does everything need to be done with fittings? I like the ability to put multiple and compound bends into EMT. Gives it a really clean look without all the fittings.

Michael

Yes, it's heated and bent all the time.

I would never use it inside a building, it sags between hangers, looks like yuk to me...............Rod.

[Michael Gantz]

Well that just won't do....

How am I supposed to present myself as a craftsmen if my conduit sags? :eek:

Again, something I probably wouldn't have figured out until it was too late.


I would never use it inside a building, it sags between hangers, looks like yuk to me...............Rod.

[John Lanciani]

Yes, it's heated and bent all the time.

I would never use it inside a building, it sags between hangers, looks like yuk to me...............Rod.

I agree. Additionally, NFPA 70 table 352.30 specifies supports every 3' for 1/2" - 1" PVC compared to every 10' (358.30 B) for EMT

[Jack Frederick]

Make your strut lengths long enough to carry your air lines too. I have a half dozen 10'x1 5/8" strut that I use for a temporary vertical support rack. I have some angle clips screwed to the rafters. With those I can anchor the strut vertically, add horizontal supports and it makes an upright square & level support at the elevation I choose to work at. I did a pretty large metal fence for the place and was able to fab up the 5x8 panels on the strut rack. It kept me off my knees and/or saved a lot of walk around time on a table. The rack takes 15 minutes to set up and about 10 to stow.

[Von Bickley]

Have you considered going with 1/2" plywood on the walls and just clamping the EMT to the plywood?

[Jim Becker]

Yes, it's heated and bent all the time.

I would never use it inside a building, it sags between hangers, looks like yuk to me...............Rod.

While I admittedly haven't use a lot of it, I've seen no sagging issues with the horizontal runs for my CNC machine and MiniSpit...but it's also supported every few feet and not carrying a heavy load inside. Any metal I have is only vertical runs.

[Michael Gantz]

Have you considered going with 1/2" plywood on the walls and just clamping the EMT to the plywood?

I did consider it. But I think finished drywall just gives a cleaner look.

[Frank Pratt]

Yes, it's heated and bent all the time.

I would never use it inside a building, it sags between hangers, looks like yuk to me...............Rod.

Nor should it be used exposed outdoors for long runs without the proper expansion joints. It expands & contracts like crazy with temp change.

[Jack Frederick]

The advantage of the plywood is you can put light stuff almost anywhere on a wall. I set my plywood walls with a decent grade of ply set vertically. All of my power is down fed so I can be into any section of wall for mods in a short time. I was going to go with 10’ ply but the cost led me to the 8’ and a 2’ with a belly band around the joint. I think it looks great, it takes a hit better than rock and it is a shop. Function first

[Andrew Seemann]

I did consider it. But I think finished drywall just gives a cleaner look.

I also did one shop in drywall, and the next in OSB. I would definitely pick OSB or plywood over the drywall. Stud locations become so much less important.

[Bill Dufour]

I think emt requires a ground wire anyway so no savings there over PVC.
Bil lD.

[Paul F Franklin]

Local codes apply, but in NEC EMT can serve as equipment grounding conductor; no separate ground wire required. You do need a jumper from any receptacles ground terminal to the box unless receptacles are rated as self-grounding (and screw-on metal cover is used). Most new 120 receptacles are now self-grounding; but most 240 are not. If EMT is fed via romex, the ground wire in the romex must be bonded to the EMT.

[Frank Pratt]

Please reconsider the drywall. I've had it both ways & currently have painted OSB. I would not want to go back to drywall. Plywood is more expensive, but would give you the clean look.

[Frank Pratt]

I think emt requires a ground wire anyway so no savings there over PVC.
Bil lD.

I don't know of any jurisdictions that require a bonding conductor in EMT, unless it's in a slab on grade. But no one in their right mind would put EMT in a slab on grade. Some projects have the bonding conductor spec'd though.

[Julie Moriarty]

Has anybody done this in their shop? If you did, do you believe it was worth the effort? Has anybody done it and regretted it?
Hanging conduit from Unistrut is commonly done on commercial jobs. Typically is is used when you have a lot of pipes running in the same direction. I've installed pipe racks for as little as maybe 4-5 but they were larger size pipe, maybe 2" or more in diameter.

IMHO, a Unistrut pipe rack overkill for a home workshop. In my last two workshops, I installed EMT and never had the occasion where I saw a pipe rack being desired. If you plan ahead for expansion - run additional conduits or oversize the pipe - you may never need to make another run from the panel. Here's an example of conduit runs in a single car garage:

http://julimorcreations.com/Images/CondBend/Conduit%20Tutorial-PWR%20PLAN.png

http://julimorcreations.com/Images/CondBend/Conduit%20Tutorial-LGT%20PLAN.png

These are the symbols
http://julimorcreations.com/Images/Electrical/ElecSymb.jpg

[Julie Moriarty]

I think emt requires a ground wire anyway so no savings there over PVC.
Bil lD.

Not when I worked in the field. The conduit is the ground.

[Julie Moriarty]

But Jim, EMT is so much prettier. I love doing conduit work & I get almost as much satisfaction out of building a beautifully done rack of EMT as I do out of a piece of furniture.
Even PVC can look pretty if you plan ahead and take your time ;)

http://julimorcreations.com/Images/JobsitePhotos/dpf_034.jpg

[Charles Lent]

If you get the idea to use larger conduit and run several circuits together, be careful. The code requires de-rating the conductor capacities in certain situations. Be careful about number of conductors allowed too, and don't mix low voltage circuits with power circuits. In a one car or larger size shop I would go with EMT, and Unistrut wherever I decided to use it. Large benders are expensive, but you can get sweeps for standard bends. !/2, 3/4, and 1" EMT conduit benders are reasonably priced and fun to use, once you understand the methods. Julie Moriarity posted a quick course in bending some time ago. She did a great job of explaining it, so it's well worth searching for.

Charley

[Julie Moriarty]

Charles, that thread, which used to be a sticky, lost all the images and became useless. But I copied most of the thread and inserted the lost images. It can be found HERE (http://julimorcreations.com/Projects/ConduitBending.htm).

[Jon Nuckles]

Charles, that thread, which used to be a sticky, lost all the images and became useless. But I copied most of the thread and inserted the lost images. It can be found HERE (http://julimorcreations.com/Projects/ConduitBending.htm).

Julie,
I haven't done any of my own electrical work and may not ever do any, but I really appreciate all of the effort you have put into advising all of us on the topic. I live in the Chicago area so, if I ever do any of that work, I will be rereading all of your posts. Thanks!
Jon

[Ron Selzer]

For at least the last twenty years on commercial work in the central ohio area, ground wires are pulled in ALL conduit systems regardless of local or state inspection. Based on observation working on jobs as HVAC controls tech and as owners rep. Not certain who requires it or if the engineers specified it.

[Julie Moriarty]

For at least the last twenty years on commercial work in the central ohio area, ground wires are pulled in ALL conduit systems regardless of local or state inspection. Based on observation working on jobs as HVAC controls tech and as owners rep. Not certain who requires it or if the engineers specified it.

35 years in the electrical trade and the only time we pulled a ground in conduit was in hospitals or for isolated grounds, which was a thing when computers came into the work world. But when I moved to Florida and installed EMT in my workshop and garage, I pulled in a ground wire because rust never sleeps here. I used set screw fittings, but even if I used compression, I would still have pulled in a ground.

You can't go wrong pulling a ground in conduit. For the most part, it isn't done because of the added cost. But there were instances - like the time GRC under slab had rusted away - that the case grounding of the pipe was lost. We got called in because of problems related to the lost ground. Had there been a ground wire, no one would have known the GRC was rusting away.