Electrical question...conduit versus in-wall wiring

[Jason Morgan]

I am wondering about what is preferable? in-wall wiring or conduit. I assume its cheaper and easier to do in-wall, but it seems easier to do conduit after all the wall board is up. That way I can insulate, put of the wall board and then put in the electrical rather than the reverse. Any suggestions one way or another?

[Ken Fitzgerald]

Jason.....In my opinion, it's easier the other way. You just drill holes to run the wire through the studs. If you use fiberglass insulation, you cut the batts to the required length and split the batt to a height slightly higher than your wire runs and install it. I'm sure it's cheaper too. Conduit, o8utlet boxes, junctions boxes,connectors all are more expensive. Of course, you have to notch the wall board or plywood...but if you are using wallboard, a dremel tool can eliminate that notching problem.

Also, that leaves the surface of your walls smooth for placing cabinets wherever you desire.

That's what I did with my shop.

[Lewis Cobb]

I am wondering about what is preferable? in-wall wiring or conduit. I assume its cheaper and easier to do in-wall, but it seems easier to do conduit after all the wall board is up. That way I can insulate, put of the wall board and then put in the electrical rather than the reverse. Any suggestions one way or another?

Hi Jason - I have a combination in my shop - partly due to to the fact that the plan was always changing. When I built the shop I put in 120V receptacles in-wall on all the walls, 220V receptacle on one wall and in the middle of the floor where the tablesaw was going to go. Lo and behold, once I have the shop insulated, sheetrocked, painted and generally "finished" I decided I needed more 220V outlets, an electrical heater outlet, move a 3 way switch, fan on the ceiling, etc etc - so I now am installing conduit around the room as well. Mainly the conduit in my room is carrying the 220 feeds, but there's a few "rogue" 120 runs as well.

I think the moral of the story is to try and plan things before you finish the room but also plan for where you are going to place conduit after you finish the room

[keith ouellette]

I did mine in wall but one thing I thought of while installing was how much big cable I could save by going with conduit. I used 8ga for some of my outlets and have one with 6ga. Instead of running up the inside of the wall over the cieling and back down I could have used individual wires in conduit and saved many feet. I didn't work out the cost difference of wire verses cable with shorter length and adding plastic conduit so it might be a minor issue. Just a thought you might look into. 12ga and under in the walls and 10ga and over outside.

[Sean Troy]

I did mine in wall but one thing I thought of while installing was how much big cable I could save by going with conduit. I used 8ga for some of my outlets and have one with 6ga. Instead of running up the inside of the wall over the cieling and back down I could have used individual wires in conduit and saved many feet. I didn't work out the cost difference of wire verses cable with shorter length and adding plastic conduit so it might be a minor issue. Just a thought you might look into. 12ga and under in the walls and 10ga and over outside.

8ga. and 6ga.? You running a power plant there? LOL

[keith ouellette]

8ga. and 6ga.? You running a power plant there? LOL

The 6ga for my ark welder (50amp breaker). The 8ga is for my 5hp planner(40amp breaker) 10ga to my 30amp breaker outlets. My power plant uses much larger cable than this. If you are going to build your own power plant you should look into it.

[Greg Peterson]

All of my 120v circuits are in the wall. Walls are insulated and wallboard will be going up soon. All the 120v circuits are for outlets and lighting, with only one circuit being dedicated to a single piece of equipment (air compressor).

If I already had the heavy equipment, I would run the 240v circuits in the wall also. But, with a very limiting budget, I have to kind take an educated guess as to what equipment I will end up having.

The service panel is in the shop(formerly known as the garage). For my 240v circuits, I'm going to set up a main lug load center and run all my 240v circuits via conduit as my needs require. This puts all the big shop equipment and its double pole breakers in its own box. If I added five 240v circuits, this would require 25% of the breaker capacity of the service panel. Better just to move those circuits over to a dedicated load center.

And, even though you don't mention it, I'll throw it out there anyway: You can never have enough outlets. It's not so much about quantity of outlets as it is the location of an outlet when you really need one. Being that the shop is a work space, things are moving in, around and out. Some outlets, usually the one you really need, are bound to hidden behind something leaning against the wall, even if you place the outlets well above 48".

So, when planning outlets, it's all about location, location, location.

[Jason Morgan]

Thanks for all the great advice. I guess I just didnt want to overlook something, but it sounds like in-wall is the obvious choice. I can put the conduit up later if I need to I guess.

Thanks!

[Terry Kelly]

I like the conduit route myself that way it is pretty easy to upgrade with in reason, 20a to a 30a circuit for example, or to add a seperate circuit if needed. Just don't over fill right off the bat and leave room for future growth. Plus if ya wanted to you could rough-in the boxes where you think you may need them in the future but not pull the wire to them til you need them.. Just a few thoughts...Na haven't done this before...

[Bruce Wrenn]

First, are you confusing the conduit, and the EMT? Conduit is threaded, and EMT assembles with mechanical fittings. With EMT, or conduit, you don't have to pull a ground wire. EMT also leaves you a passage way for future changes, without ripping off wall finish. Please don't install 1/2" stuff though. There isn't enough room to go back later and add another circuit. The 3/4 stuff will only cost a few bucks more. In my shop I have a nine foot ceiling. I have several runs of surface mounted EMT near ceiling. Behind the finished wall, I drop down with EMT also.

[Randall Davis]

First, are you confusing the conduit, and the EMT? Conduit is threaded, and EMT assembles with mechanical fittings. With EMT, or conduit, you don't have to pull a ground wire. EMT also leaves you a passage way for future changes, without ripping off wall finish. Please don't install 1/2" stuff though. There isn't enough room to go back later and add another circuit. The 3/4 stuff will only cost a few bucks more. In my shop I have a nine foot ceiling. I have several runs of surface mounted EMT near ceiling. Behind the finished wall, I drop down with EMT also.

EMT is conduit threaded (rigid)is also conduit.
If you have a one man hobby shop save time and money put some thought in to your layout and use 12/2 romex for the general duty outlets. Wire your dust collecter, table saw, compresor to manufacterers specs. If your planer, jointer, drill press and table saw are all 240 volt save $ on breakers and panel space, run one 30 amp circuit to feed all of them unless you have figured a way to run two of these machines at the same time.

[Rod Sheridan]

Since my shop is in the basement, and the walls are poured concrete, I used EMT for all my wiring except lighting.

I used 1/2" EMT with qty 3 12 gauge T90 conductors ( two lines, one neutral) plus a #14 ground.

This was used to feed one duplex 15A 240 V receptacle (6-15R) and one duplex 15A 120 V receptacle in a split configuration (5-15R) fed from a 15 A 2 Pole breaker.

The above receptacles were mounted in a 4 inch square box, which gave me a 15A 240 circuit for machinery, and two 15A 120 circuits for machinery. This is suitable for my 3HP saw, shaper and planer, as well as the 2HP Bandsaw, as well as the lathe and drill press.

I doubt if I'll ever have to upgrade it, however 1/2 inch EMT with T90 conductors, you can install qty 9 12 gauge, or qty 5 10 gauge conductors, not that I'd ever use fill values that high however.

The conduit route allows you to change the wiring configuration easilly, just pull in different conductors as your requirements change.

Regards, Rod.

[Greg Crawford]

Being in Wisconsin, I'm puzzled at why heating hasn't come into play. With every penetration through the walls and ceiling, heated air escapes (or cold air enters) the conditioned space. While this may seem minimal, it also means that cold air is passing through the insulation, reducing it's effectiveness. In my shop, the final plan is all conduit, with controlled ventilation passing through a heat exchanger to cool the incoming air and remove some of the moisture. Of course, my conditions are hot and humid, but the principles are the same.

[Cliff Rohrabacher]

Metal Conduit allows you to use Multi strand wire. Multi. Strand carries more current.

[Rob Russell]

FYI, "conduit" is a generic term used for round raceway. The typical round metal tubing used as raceway is EMT - Electrical Metallic Tubing and has not threads. The EMT connectors are all screw fittings, where a set screw clamps down on the EMT.

There are other types of raceway that are allowable - non-metallic/PVC is another type. It comes in varying wall thicknesses - Schedule 40, Schedule 80, etc. that's the stuff you glue together.