Running electric in new construction, surface mount or flush?

[Jon Shoop]

Building a 42x42 with scissor trusses. Thinking about metal cieling and wall surface covering. Electric and air, considering surface mount to keep walls sealed and well insulated. Anyone have reccomendations pro or con? Thanks

 

[plout99]

I am going surface mount for everything mainly because I have no idea where I am putting everything, shop is 32 x48 with a second floor over half and will be metal and wood fabrication along with vehicle maintenance. Conduit will be harder and more money initially but easier if I need to add or remove down the road. Also the walls will be air sealed better so that is a secondary bonus.

 

[jeepxj]

I am going surface mount for everything mainly because I have no idea where I am putting everything, shop is 32 x48 with a second floor over half and will be metal and wood fabrication along with vehicle maintenance. Conduit will be harder and more money initially but easier if I need to add or remove down the road. Also the walls will be air sealed better so that is a secondary bonus.

Just put in 4' of plywood horizontal as the bottom run on the wall. then rip a section down to 18" and lay that horizontally above the base run. then run metal or sheet rock above all that.


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more plywood or metal to ceiling.




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18" electrical/air/future run strip you can easily remove to in wall wires
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4x8 sheets

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[Noltz]

Every commercial shop has surface mount wiring. It's not at all out of place in a workplace to see exposed conduit. I've even seen it in some "urban renewal" magazine layouts where old warehouses and such have been converted to residential use. Well thought out and neatly done looks good.

 

[nadogail]

IMHO, With surface mount you can show off your conduit bending skills and your ability to plan an attractive layout.

Any shortcomings in those areas will also be demonstrated.

 

[Dagny]

Ag steel with the humps no brainer thinwall EMT.

 

[Red 17]

Poured the floor yet?

If not, 1 or 1 1/2" conduit under the floor, straight runs from where the panel is to where you think you want juice in the walls. One to each corner if you want, with one in the middle. Pup it up inside any stem wall so it's inside the wall.

Serving suggestion.

 

[Dandy1008]

I always vote for exposed. We have exposed in 2 commercial buildings and it is so much easier to add/modify circuits and air lines. Some day I am hoping to build a shed/house (Shouse) and would used exposed in all possible locations both in the living quarters and the workspace. It is just that much easier. Now, if you don’t think you will ever be adding/changing any circuits then in-wall would work fine. For a commercial/industrial type space I do feel exposed actually looks more at home.

 

[klassenl]

Both have their merits. Wiring in the walls will be cheaper and faster. Pipe has the advantage of -some- flexibility.

 

[penright]

There were two pieces of advice I got from this forum when I started. 1. Don't try and do all that you might need someday. 2. Was use 3/4" conduit. Which would lead to "outside" the wall. Just yesterday, I took advantage of the 3/4" fill capacity and ran a new circuit that was not planned when the shop was started. Well, it was planned, just was not sure where it would wind up. You learn a lot about what you will need as you start to use and developed the space.

Also, take pictures before putting up the walls with a tape measure stretched. In my opinion, you can not document what is behind walls too much.

 

[sberry]

Wiring after is a tailored job, wire before is total speculation on so much of it. When I plan too far ahead with all the details I end up with a lot of wire parked I never use. While the cost,,, comparing apples to apples is a bit lower with cable in the walls often it takes so much less after the fact and it gets where it needs to be.

 

[penright]

Wiring after is a tailored job, wire before is total speculation on so much of it. When I plan too far ahead with all the details I end up with a lot of wire parked I never use. While the cost,,, comparing apples to apples is a bit lower with cable in the walls often it takes so much less after the fact and it gets where it needs to be.

You know I was quoting you (sberry).
That was one lesson I did not have to learn the hard way.

 

[Crazyjake8493]

I prefer to air seal and insulate really well, finish the walls, then surface mount everything. Plus I enjoy running EMT.

 

[sberry]

You know I was quoting you (sberry).
That was one lesson I did not have to learn the hard way.

I been thru this a challenge couple of times. Nothing seems to turn out exactly like the plans. You don't gotta get it all in one pipe. Nothing is as good as single circuit in pipe to the equipment, to a welder outlet or compressor, it reduces that fill from other pipes. Is easy to add another outlet or extend generals that have to be gfci. The cost of extra circuits has went up. I like pipe cause it's cheap to send an extra wires to fixture boxes although I do it with cable too.

 

[sberry]

The cost of materials in this size job isn't a deal breaker. The difference rather irrelevant. One thing is to do some design so you dont have to use every fitting they ever invented. All the non standard,, not a male threaded adapter or coupling adds cost and using a bit more room to bend is simpler than. Lb, offset. Not every piece needs to be 3/4, it doesn't add much but this gang doesn't need inch and 4 11/16, etc, use deep 4x4 combination where it's going to have big devices, I use shallow and some 90 bends going in to them isn't a bad thing. A few handi have their place at the end, for equipment switches, etc.
Not every place needs every what if, I got 1000's ft of pipe never had to come back to put a welder outlet in the ceiling, very few other wires either really. Don't need 300A ****** tig in every corner or in the bathroom. 1/2 pipe has it's place, in fact most of the place can be done with it just as well especially diy.

 

[sberry]

Every time I do this I can to the same with a couple less pieces. My service looks great, the inspector at the time a notorious **** said, that's the way it should be done but didn't stare at it long enough there could have been one less move. Last one I got dead nuts, 2 before I miss a free fitting. No one but a critical master would notice as it all looks right and is acceptable. Every piece adds an hour.

 

[sberry]

I prefer to air seal and insulate really well, finish the walls, then surface mount everything. Plus I enjoy running EMT.

EMT in this kind of install is really the gold standard, nothing as good as pipe, jump off it to add extra. Never rodent damage, no o e drives a nail in it, so easy to change a little. I did some with the idea of adding later,, never did need it, would have had it in the walls unused if it had to be covered.
I wired the shop as I moved in, some extra right off where I had some cords, the farther out the better. I wired the storage before I moved in and outfitted,,, wayyyyyyyy overkill.
Look.of that creative switch add on in the last pic,,, I think a helper added it for switches, they were behind shelf maybe
It should have been in line, in series but he didn't want to unwire, the electric doesn't know I guess.
Fore anyone blows a gasket the cord feeds that equipment, plug on the other end.

 

[sparky 1971]

+1 for emt. It looks nice when run straight and all the bends line up. You can almost always add another circuit through the existing pipe. I did wire one building with the metal on the walls and flush mount devices. The builder crew marked where the centers of the ribs would be, I used 4" square boxes with a bracket, left a little extra wire so if the box wasn't centered up they could just pull a couple screws out and move the box over a couple inches or so. I don't know how many, if any needed to be moved. I did have to go back a couple years later and add a circuit for a fancy saw. That was done in emt and since it was all by itself, I thought it looked like ****.

As long as the metal ribs are 3/4", and most of them are, use Raco 232CS boxes. The knockouts on two sides are punched out a little farther from the back than normal allowing the conduit to lay right on top of the ribs with no offset required. Of course, if it's a Morton Building, the ribs are an inch deep and the boxes won't work as intended.