# 1" EMT through concrete



## benthehood (Aug 11, 2017)

Is it possible to run 1" EMT down a wall and make a 90 directly into the same wall it's running down? I was going to try using some unistrut and make a 90 right in but 1" is so big that I'm not sure if it will go in very well. I could use an LB but I'd rather just bend it if possible.


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## backstay (Feb 3, 2011)

With a big enough hole.


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## MechanicalDVR (Dec 29, 2007)

Welcome aboard @benthehood!

Are you not familiar with a 1" emt bender?


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## benthehood (Aug 11, 2017)

HAHA.. the hole will only be 1" I'm thinking I will either have to offset into a 90 or just use an LB


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## MechanicalDVR (Dec 29, 2007)

benthehood said:


> HAHA.. the hole will only be 1" I'm thinking I will either have to offset into a 90 or just use an LB


It's impossible to get 1" emt through a 1" hole.


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## benthehood (Aug 11, 2017)

Of course. I'm not asking if it's possible to bend 1". Just about that specific scenario.


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## benthehood (Aug 11, 2017)

... 1 1/4" hole to be EXACT, and I'm free to use unistrut if it will make that 90 go into the hole.


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## MechanicalDVR (Dec 29, 2007)

benthehood said:


> Of course. I'm not asking if it's possible to bend 1". Just about that specific scenario.


Then you just need to explain it a little better.

If you are asking if a 1" EMT running down the surface of a wall can be bent to go through said wall then no, you'd be best off with an LB.


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## MechanicalDVR (Dec 29, 2007)

benthehood said:


> ... 1 1/4" hole to be EXACT, and I'm free to use unistrut if it will make that 90 go into the hole.


As soon as you mention unistrut you lose me.


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## backstay (Feb 3, 2011)

MechanicalDVR said:


> As soon as you mention unistrut you lose me.


Strut would move the conduit away from the wall so the radius won't hit. But you need to be what, 4 inches away.


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## Jmcstevenson (Sep 11, 2010)

If you bend a gooseneck it will work. Ugly as sin though. Manufactured 90's are always a bit tighter.. knocking out the concrete around the sweep of your bend is something I've done but if youre asking if it'll fit into a tight round hole the same OD as your pipe then no. 

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## MechanicalDVR (Dec 29, 2007)

backstay said:


> Strut would move the conduit away from the wall so the radius won't hit. But you need to be what, 4 inches away.


Two thicknesses of deep strut and one of shallow strut and it should make it in clean. 


Might look a little strange when an LB would be cleaner.


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## splatz (May 23, 2015)

I think he means he'd set the 1" on strut to get it off the wall a little bit but a 90 in 1" still won't be anywhere close. 

You could make the "shepherds crook" bend, the question mark shaped bend, that's for this exact situation. It's basically an offset below the 90.


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## Jmcstevenson (Sep 11, 2010)

splatz said:


> I think he means he'd set the 1" on strut to get it off the wall a little bit but a 90 in 1" still won't be anywhere close.
> 
> You could make the "shepherds crook" bend, the question mark shaped bend, that's for this exact situation. It's basically an offset below the 90.


We call those goosenecks. Your name sounds less scabby though. It would not look as good as your photo as there wouldn't be an obstacle in his scenario. 

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## benthehood (Aug 11, 2017)

splatz said:


> I think he means he'd set the 1" on strut to get it off the wall a little bit but a 90 in 1" still won't be anywhere close.
> 
> You could make the "shepherds crook" bend, the question mark shaped bend, that's for this exact situation. It's basically an offset below the 90.


thanks for the photo. This is exactly what I was thinking about attempting, but I think it's a bit much considering it's on an exterior of a building. Gonna go with an LB.


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## MechanicalDVR (Dec 29, 2007)

benthehood said:


> thanks for the photo. This is exactly what I was thinking about attempting, but I think it's a bit much considering it's on an exterior of a building. Gonna go with an LB.


:thumbsup:

LB is the way to go and look clean.


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## telsa (May 22, 2015)

To the OP: you ought to have mentioned that you were entering the building from a vertical run outside.

In such circumstances LBs or NEMA3R cans are uniformly used.

The trick with LBs is to make sure that your wire fill is not going to be 'tight.'

When that happens, you burn a lot of time trying to get the conductors in. 

This seems trivial in small pipes. It gets absurd with feeders.

The other trick is that such a building penetration, if sloppy, won't be hidden by the LB.


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## Southeast Power (Jan 18, 2009)

If the LB isnt going to be easy to use, you can elongate the entry hole and patch it, I think I would do that if it were 20' in the air an a pain to pull through come wire pull day.


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## backstay (Feb 3, 2011)

Suncoast Power said:


> If the LB isnt going to be easy to use, you can elongate the entry hole and patch it, I think I would do that if it were 20' in the air an a pain to pull through come wire pull day.


Like this.


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## lighterup (Jun 14, 2013)

we would not get away with using emt through concrete or embedded in
concrete. We would have to use rigid steel or pvc.


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## MechanicalDVR (Dec 29, 2007)

lighterup said:


> we would not get away with using emt through concrete or embedded in
> concrete. We would have to use rigid steel or pvc.


So when you rough a building made from concrete block you can't bury EMT inside the webbing to your boxes?


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## lighterup (Jun 14, 2013)

MechanicalDVR said:


> So when you rough a building made from concrete block you can't bury EMT inside the webbing to your boxes?


Yeah that is what I'm saying. Not just AHJ's but blue prints will
spec pvc when under or in concrete slabs then transition to emt 
above grade.

I was told ( and I know what 2014 code says-which is it is permissible
under or in concrete) , but I was told by engineer on a mattress factory I 
contracted work for (which was a Lubrizol factory at one time) that they
did not want emt in the slab cause she said it would have a corrosive
effect and rot it out.


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## MechanicalDVR (Dec 29, 2007)

lighterup said:


> Yeah that is what I'm saying. Not just AHJ's but blue prints will
> spec pvc when under or in concrete slabs then transition to emt
> above grade.
> 
> ...


Wow, that is crazy.

Every hospital and school I have ever worked on had EMT inside the block walls and you know some of it are completely encased in cement.


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## lighterup (Jun 14, 2013)

MechanicalDVR said:


> Wow, that is crazy.
> 
> Every hospital and school I have ever worked on had EMT inside the block walls and you know some of it are completely encased in cement.


I am talking thin wall here . are you?


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## MechanicalDVR (Dec 29, 2007)

lighterup said:


> I am talking thin wall here . are you?


Yes, standard EMT.

Normally installed in 30" pieces as the walls are laid up.


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## lighterup (Jun 14, 2013)

MechanicalDVR said:


> Yes, standard EMT.
> 
> Normally installed in 30" pieces as the walls are laid up.


See I have occasionally found rotted emt under cement.

The last one was in a residential crawl space with a cement slab 
for a floor.

The HO complained they were having some outages in certain rooms
on & off until after Christamas they never came back on.

I spent a couple hours in that crawl space checking j box to j box , 
making my way toward the garage panel. 

discovered emt went underground for about 10' until it resurfaced
on the opposite side of the foundation wall in the garage where the
main was.

Voltage checks at each circuit breaker read good at source , but
nothing at first j box in crawl.

I tried to see if I could pull out feeders (1-1/2" emt run)but they 
would not budge. There was a corrosive white powder coming out from
the emt underground.

Gave HO a price to hammer drill the floor up and repair & replace 
but of course never got back to me. Whatever...is was s**t job anyway.


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## telsa (May 22, 2015)

Oakland has a SPECIFIC prohibition against EMT within slab concrete.

IIRC, this prohibition is found all around the Bay Area.

Nevada is even more severe. Due to soil conditions ( it used to be at the bottom of the ocean ) you'll run into prohibitions against buried GRC and IMC, too.


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## MechanicalDVR (Dec 29, 2007)

telsa said:


> Oakland has a SPECIFIC prohibition against EMT within slab concrete.
> 
> IIRC, this prohibition is found all around the Bay Area.
> 
> Nevada is even more severe. Due to soil conditions ( it used to be at the bottom of the ocean ) you'll run into prohibitions against buried GRC and IMC, too.


Interesting enough.


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## lighterup (Jun 14, 2013)

telsa said:


> Oakland has a SPECIFIC prohibition against EMT within slab concrete.
> 
> IIRC, this prohibition is found all around the Bay Area.
> 
> Nevada is even more severe. Due to soil conditions ( it used to be at the bottom of the ocean ) you'll run into prohibitions against buried GRC and IMC, too.


It could be a regional thing here too. Under Lake Erie is a massive 
salt mine that Morton Salt , has a plant right off Lake Erie in Mentor 
Ohio , harvests salt from ...so maybe there is enough in our soil to
do damage.


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## MechanicalDVR (Dec 29, 2007)

lighterup said:


> It could be a regional thing here too. Under Lake Erie is a massive
> salt mine that Morton Salt , has a plant right off Lake Erie in Mentor
> Ohio , harvests salt from ...so maybe there is enough in our soil to
> do damage.


Oh wow, never knew that about Ohio.


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## Lone Crapshooter (Nov 8, 2008)

Have used EMT in a hospital in the floor slabs above the ground floor . In the drybed under the ground floor it was all ridgid. Inside masonry walls is EMT.

LC


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## MechanicalDVR (Dec 29, 2007)

Lone Crapshooter said:


> Have used EMT in a hospital in the floor slabs above the ground floor . In the drybed under the ground floor it was all ridgid. Inside masonry walls is EMT.
> 
> LC


Same here.


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