Tips for EMT in dwelling unit

[lordofpi]

Hi all. Long time, no post; hope all of you are well. Normally, I don't get involved with too much residential work, but a buddy of mine -- who does mostly residential -- stepped aside and recommended me for this job because the contractor has mandated it be done in EMT due to local ordinance. My piping skills are good, but I am used to dealing with mostly CMU/block walls and exposed-utility installs. I guess this question goes mostly to guys from the Chicago area. I need some tips for running through studs and solid joists and securing EMT to satisfy code the easiest way possible. I tried to search the topic, but of course "EMT" is fewer than four letters long, so it will not parse.
Before I click "Post", two things that have been rattling around in my head: (1) Where in studs is it best to locate holes? Dead center and offset at boxes, or closer to surface to keep in line with box connectors.
And (2), where how is raceway to be supported in long vertical runs (i.e., though floors).
All opinions are appreciated!

 

[LarryFine]

1. You'd probably be better off with notching studs and using protector plates. No hole threading, no offsets, and you'd save a hundred couplings.

2. How about 2x4 blocks nailed across stud bays like fire blocks, except rotated so the 3.5" side is vertical?

 

[iwire]

1. You'd probably be better off with notching studs and using protector plates.

Larry if someone did that to my new home I would flip out.

A notch here and there is one thing but to notch entire walls would be a different story.

There are some pictures somewhere on this forum of a Chicago EMT job, I will look for them.

 

[iwire]

Well I found where the pictures where but the server they are own is now gone.

I do not recall any notching, a lot of vertical EMTs and a lot of couplings.

They also do not bother to closely follow the lumber like we would when the work would be exposed.

 

[lordofpi]

Larry if someone did that to my new home I would flip out.

A notch here and there is one thing but to notch entire walls would be a different story.

I must say I agree with you Bob. This just seems, I don't know, un-neat somehow. Plus any unevenness in the drywall will just be blamed on the electrical by the G/C, even if it has nothing to do with it. The 2X4 stringers for strapping seems like a nice idea though. This is definitely going to be interesting. Maybe for a real challenge, I ought to try to do the whole thing in threaded IMC!

 

[jrannis]

In each room you hit the ceiling light outlet and "spider out" to each wall.
It is rare to have horizontal runs.
Exterior block walls usually have a couple of "wall wrap" double 90s here and there.
Make sure you get in ahead of the furring strip installation.

 

[jrannis]

I must say I agree with you Bob. This just seems, I don't know, un-neat somehow. Plus any unevenness in the drywall will just be blamed on the electrical by the G/C, even if it has nothing to do with it. The 2X4 stringers for strapping seems like a nice idea though. This is definitely going to be interesting. Maybe for a real challenge, I ought to try to do the whole thing in threaded IMC!

Stringers? Seems like you would just offset over to the closest stud.

 

[billsnuff]

try post 49

try post 49

http://forums.mikeholt.com/showthread.php?t=81632&page=5

when you get there open a new page and copy and paste the pictures links from the post to the new page to see them. Or maybe PM George.

 

[lordofpi]

I know Scott hasn't posted in a while, but my hat is off to some nice work. As is mentioned in the thread by some of the responders, there is definitely a lack of securing and support for the raceway -- at least at the time the photos were taken.

While making offsets is not a problem per se, offsetting to studs will add to installation time and I probably will run out of room in a lot of locations, e.g. large switch boxes. Also, I suppose that -- as some one else said -- I will be using a lot of couplings. Normally a lack of such is a mark of pride since it means that everything was laid out perfectly, but in this case I think it will just add to the work I have by me trying to figure out out to snake long distances of bent steel tubing into studs.

By the way, I like the concept of spidering out from the ceiling, though I am never crazy about lots of holes in joists (as opposed to studs). Probably (at least for receptacles), I will have one branch for each wall coming from the ceiling, and the rest running horizontally (at 24" AFF) to supply each receptacle.

I was just looking through this:
Caddy Stud Fasteners
and some of these items might really come in handy here.

 

[iwire]

The pics in two posts

 

[iwire]

Part 2

 

[crossman]

Man, if I was the Code dictator, I would make it a requirement to run EMT in houses, simply because those pics are so cool!

 

[iwire]

It is great looking work, even with the NEC violations. :grin: (lack of supports)

 

[macmikeman]

I would love it if the nec started requiring all emt in dwellings, and romex stopped getting made. Then we could all be real men again. :grin: I bet you encounter less hack add on work in Chicago than you get in other parts of the country due to the added skill level required to do the work as evidenced in the pictures that Bob has posted. The pipe bending is way beyond what the carpenters in my area would attempt to try on their own.

 

[crossman]

The pipe bending is way beyond what the carpenters in my area would attempt to try on their own.

LOL! Nice!

 

[C3PO]

If I had to guess I would say the hacks in that area still just add on with nm cable. If they are not getting it inspected what's to stop them?

 

[crossman]

I wouldn't even worry about that. All that pipe work on the original install would be enough for me!

 

[crossman]

It is great looking work, even with the NEC violations. :grin: (lack of supports)

I wonder if Chicago requires an EGC to be pulled in or if they can use the EMT. If they allow the EMT as equipment ground, proper strapping is vital. For instance, in some of those vertical runs, they are sure to get banged around during construction, and this could definitely cause the locknut in the box to loosen. Strapping EMT is not solely for support. It is to help insure and maintain proper grounding too.

 

[iwire]

If they allow the EMT as equipment ground, proper strapping is vital.

I know that some Chicago guys have said they do not pull EGCs.

For instance, in some of those vertical runs, they are sure to get banged around during construction, and this could definitely cause the locknut in the box to loosen. Strapping EMT is not solely for support. It is to help insure and maintain proper grounding too.

I agree to some extent but I really do not see any conduits in those pictures that I would expect to be loose. If they tighted the fittings well a little bit of banging around during constrution is not (IMO) going to loosen anything up.

 

[crossman]

Maybe, maybe not. In your post #11, in the last pic, if the vertical run with the offset were pushed back at the top of the offset, it could loosen the locknut. Of course, the locknut could be retightened fron inside the box, but would it be?

I think my statement stands that EMT strapping serves two purposes. One for support, the other to help maintain continuity by preventing the EMT system from wiggling arouns and transmitting this movement to fittings, thereby loosening them.