# When is a ufer ground required?



## MHElectric (Oct 14, 2011)

I may be wrong, and if I am let me know, but my understanding is that if a building is constructed with steel and metal, it requires a ufer ground. If the building is stick built, it does not. Correct?


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## flyboy (Jun 13, 2011)

If you mean ufer ground as in "encased in concrete" the quick answer to your question would be no in an existing building.


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## Black Dog (Oct 16, 2011)

MHElectric said:


> I may be wrong, and if I am let me know, but my understanding is that if a building is constructed with steel and metal, it requires a ufer ground. If the building is stick built, it does not. Correct?



When Building bomb storage vaults....






:laughing::laughing:


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## flyboy (Jun 13, 2011)

I'm pretty sure that even in new construction a stick built structure will require a ufer ground in the foundation/footing concrete.


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## MHElectric (Oct 14, 2011)

They dont require us to put them in when we do houses. At least not in my area they dont.

Ive got a metal building coming up out of the slab, and I threw a 20 ft peice of rebar with a 90 bent at the end coming up right next to my panel. I wasn't100% sure if i needed it or not, but I thought it would be better to do it now than to bust up concrete later.


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## flyboy (Jun 13, 2011)

III. Grounding Electrode System and Grounding Electrode Conductor
250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.

Exception:  Concrete-encased electrodes of existing buildings or structures shall not be required to be part of the grounding electrode system where the steel reinforcing bars or rods are not accessible for use without disturbing the concrete.

250.52 Grounding Electrodes.

(A) Electrodes Permitted for Grounding.

(1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductor(s) or jumper(s), if installed.
•
(2) Metal Frame of the Building or Structure. The metal frame of the building or structure that is connected to the earth by one or more of the following methods:

(1) At least one structural metal member that is in direct contact with the earth for 3.0 m (10 ft) or more, with or without concrete encasement.

(2) Hold-down bolts securing the structural steel column that are connected to a concrete-encased electrode that complies with 250.52(A)(3) and is located in the support footing or foundation. The hold-down bolts shall be connected to the concrete-encased electrode by welding, exothermic welding, the usual steel tie wires, or other approved means.

(3) Concrete-Encased Electrode. A concrete-encased electrode shall consist of at least 6.0 m (20 ft) of either (1) or (2):

(1) One or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 13 mm (½ in.) in diameter, installed in one continuous 6.0 m (20 ft) length, or if in multiple pieces connected together by the usual steel tie wires, exothermic welding, welding, or other effective means to create a 6.0 m (20 ft) or greater length; or

(2) Bare copper conductor not smaller than 4 AWG

Metallic components shall be encased by at least 50 mm (2 in.) of concrete and shall be located horizontally within that portion of a concrete foundation or footing that is in direct contact with the earth or within vertical foundations or structural components or members that are in direct contact with the earth. If multiple concrete-encased electrodes are present at a building or structure, it shall be permissible to bond only one into the grounding electrode system.

Informational Note:  Concrete installed with insulation, vapor barriers, films or similar items separating the concrete from the earth is not considered to be in “direct contact” with the earth.

(4) Ground Ring. A ground ring encircling the building or structure, in direct contact with the earth, consisting of at least 6.0 m (20 ft) of bare copper conductor not smaller than 2 AWG.

(5) Rod and Pipe Electrodes. Rod and pipe electrodes shall not be less than 2.44 m (8 ft) in length and shall consist of the following materials.

(a) Grounding electrodes of pipe or conduit shall not be smaller than metric designator 21 (trade size ¾) and, where of steel, shall have the outer surface galvanized or otherwise metal-coated for corrosion protection.
(b) Rod-type grounding electrodes of stainless steel and copper or zinc coated steel shall be at least 15.87 mm (5⁄8 in.) in diameter, unless listed.

(6) Other Listed Electrodes. Other listed grounding electrodes shall be permitted.

(7) Plate Electrodes. Each plate electrode shall expose not less than 0.186 m2 (2 ft2) of surface to exterior soil. Electrodes of bare or conductively coated iron or steel plates shall be at least 6.4 mm (¼ in.) in thickness. Solid, uncoated electrodes of nonferrous metal shall be at least 1.5 mm (0.06 in.) in thickness.

(8) Other Local Metal Underground Systems or Structures. Other local metal underground systems or structures such as piping systems, underground tanks, and underground metal well casings that are not bonded to a metal water pipe.

(B) Not Permitted for Use as Grounding Electrodes. The following systems and materials shall not be used as grounding electrodes:

(1) Metal underground gas piping systems
(2) Aluminum


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## flyboy (Jun 13, 2011)

MHElectric said:


> They dont require us to put them in when we do houses. At least not in my area they dont.
> 
> Ive got a metal building coming up out of the slab, and I threw a 20 ft peice of rebar with a 90 bent at the end coming up right next to my panel. I wasn't100% sure if i needed it or not, but I thought it would be better to do it now than to bust up concrete later.


You made the right decision! :thumbsup:


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## chicken steve (Mar 22, 2011)

Iirc, the CEE was a big 250 flap back a few cycles ago, until the accessibility ex was put in place.

The state inspector dept even sent out form letters to all the area cement heads, which did little to no real good without teeth

Basically, we're going to show up and even bid _after_ the pour, which is where i don't worry about CEE's 

~CS~


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## chicken steve (Mar 22, 2011)

MHElectric said:


> They dont require us to put them in when we do houses. At least not in my area they dont.
> 
> Ive got a metal building coming up out of the slab, and I threw a 20 ft peice of rebar with a 90 bent at the end coming up right next to my panel. I wasn't100% sure if i needed it or not, but I thought it would be better to do it now than to bust up concrete later.


last time i did that the poco thought i cheated on a Gbar.... ~CS~


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## Mshow1323 (Jun 9, 2012)

Any and all grounding electrodes that are present must be used. If it's there, bond, if there isn't any, install at least one. The exception is why we don't typically use the ufer. Like CS said, most of the time we don't step foot on a project until after the pour. 

NEC 2011.


> III. Grounding Electrode System and Grounding Electrode Conductor
> 250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.
> Exception:  Concrete-encased electrodes of existing buildings or structures shall not be required to be part of the grounding electrode system where the steel reinforcing bars or rods are not accessible for use without disturbing the concrete.


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## Mshow1323 (Jun 9, 2012)

MHElectric said:


> I may be wrong, and if I am let me know, but my understanding is that if a building is constructed with steel and metal, it requires a ufer ground. If the building is stick built, it does not. Correct?


The shorter answer is, you're wrong. If it's available, it's a necessity.


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## MHElectric (Oct 14, 2011)

Mshow1323 said:


> Any and all grounding electrodes that are present must be used. If it's there, bond, if there isn't any, install at least one. The exception is why we don't typically use the ufer. Like CS said, most of the time we don't step foot on a project until after the pour.
> 
> NEC 2011.


So with that logic, we could argue that if we were not on a job before the slab was poured then we are not responsible for the ufer ground? I didn't put any conduit in the slab, so therefore I technically didn't need this rebar ground? Maybe?

I honestly thought it had to do with the materials used to build the building. Nobody puts a ufer ground in when doing house, but structures with steel & metal, its common. Of course I will be hitting all the other GE available - building steel & grd rod.


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## Mshow1323 (Jun 9, 2012)

Even the good book has loop holes. "Sorry Mr. Inspector sir, I didn't get here until the walls we up. There is no available CCE."


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## Sbargers (Mar 28, 2013)

MHElectric said:


> So with that logic, we could argue that if we were not on a job before the slab was poured then we are not responsible for the ufer ground? I didn't put any conduit in the slab, so therefore I technically didn't need this rebar ground? Maybe?
> 
> I honestly thought it had to do with the materials used to build the building. Nobody puts a ufer ground in when doing house, but structures with steel & metal, its common. Of course I will be hitting all the other GE available - building steel & grd rod.


Where I'm at it is required even on track houses, we do not install but concrete guys put it right next to our panel every time they also allow al. For ufer

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## aftershockews (Dec 22, 2012)

Sbargers said:


> Where I'm at it is required even on track houses, we do not install but concrete guys put it right next to our panel every time they also allow al. For ufer
> 
> Sent from my XT1030 using electriciantalk.com mobile app


How do the concrete guys know where your panel is?


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## chicken steve (Mar 22, 2011)

Sometimes it's the meter, poco spots it, crete heads stick a rebar up , we make it into the intersystem G-bar...

~CS~


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## Dennis Alwon (May 9, 2009)

MHElectric said:


> So with that logic, we could argue that if we were not on a job before the slab was poured then we are not responsible for the ufer ground? I didn't put any conduit in the slab, so therefore I technically didn't need this rebar ground? Maybe?


That is the way NC looks at it but IMO that is not what the NEC requires. I use ufers all the time as it is the best electrode for the money that you can get. With all the electronics etc why wouldn't you use it?

The NEC changed the wording to avoid this particular thinking yet NC just ignores it. I wish they would enforce it.


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## Dennis Alwon (May 9, 2009)

The argument about not accessible is BS IMO, that is like saying we don't need outlets on the wall because the sheetrock got installed before the electrician got there. It is or was accessible and the electrician did not use it. The NEC does not say if it is accessible when the electrician gets there.

The except is there to avoid busting the footer when a remo job is being done.


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## Sbargers (Mar 28, 2013)

aftershockews said:


> How do the concrete guys know where your panel is?


Track homes show them one time they put I'm same place every time,

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## theJcK (Aug 7, 2013)

Dennis Alwon said:


> That is the way NC looks at it but IMO that is not what the NEC requires. I use ufers all the time as it is the best electrode for the money that you can get. With all the electronics etc why wouldn't you use it? The NEC changed the wording to avoid this particular thinking yet NC just ignores it. I wish they would enforce it.


yea.. even on my side of the state. never been enforced.. inspectors never asked about it.. but i have always installed it. this helps create the equipotential plane does it not?..


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## Dennis Alwon (May 9, 2009)

I would not call it the equipotential plane but rather a place where surges can be safely dissipated. The lower the ohm reading the better chance you have of dissipating surges from the power company or lightning


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## MHElectric (Oct 14, 2011)

Alright. thanks guys. Sounds like Im good.


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## cavie (Sep 12, 2014)

flyboy said:


> You made the right decision! :thumbsup:


 up until the point you exposed the rod to bare ground. It will rust off and you will have nothing. You must turn up inside a wall and provide access for connection to the service or use acorn clamp on rod in concrete and run copper wire to the service.


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## macmikeman (Jan 23, 2007)

cavie said:


> up until the point you exposed the rod to bare ground. It will rust off and you will have nothing. You must turn up inside a wall and provide access for connection to the service or use acorn clamp on rod in concrete and run copper wire to the service.


Turning up the rebar into a wall here is considered a rust point in itself and is not allowed. We must hit the rebar in the bottom of the footing period.


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## theJcK (Aug 7, 2013)

what are thoughts on bare aluminum encased in concrete?..


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## Dennis Alwon (May 9, 2009)

theJcK said:


> what are thoughts on bare aluminum encased in concrete?..


:no::no::no: Sorry look at 250.64(A)



> 250.64 Grounding Electrode Conductor Installation.
> Grounding electrode conductors at the service, at each building
> or structure where supplied by a feeder(s) or branch circuit(
> s), or at a separately derived system shall be installed as
> ...


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## theJcK (Aug 7, 2013)

interesting. ive never seen that reference but ironically seen a ufer conductor just recently that was a bare #2? maybe, just shooting straight up out of slab. thought it strange.. even looked up on my phone real quick (still open in Safari) but hadnt looked it up in NEC yet. thanks Dennis! 

this is what came up first.. some concrete forum.. 
"Aluminum reacts with the alkalis (OH) found in portland cement concrete. When these two chemicals are combined, the reaction produces hydrogen gas. This is why, when the reaction occurs in wet concrete, you'll notice tiny bubbles coming to the surface of a slab."


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## macmikeman (Jan 23, 2007)

theJcK said:


> interesting. ive never seen that reference but ironically seen a ufer conductor just recently that was a bare #2? maybe, just shooting straight up out of slab. thought it strange.. even looked up on my phone real quick (still open in Safari) but hadnt looked it up in NEC yet. thanks Dennis!
> 
> this is what came up first.. some concrete forum..
> "Aluminum reacts with the alkalis (OH) found in portland cement concrete. When these two chemicals are combined, the reaction produces hydrogen gas. This is why, when the reaction occurs in wet concrete, you'll notice tiny bubbles coming to the surface of a slab."


Using aluminum powder mixed into concrete is how AAC block is created- that soft kind that you can drill into with a paddle bit and not hurt the bit a bit.


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## Dennis Alwon (May 9, 2009)

theJcK said:


> interesting. ive never seen that reference but ironically seen a ufer conductor just recently that was a bare #2? maybe, just shooting straight up out of slab. thought it strange.. even looked up on my phone real quick (still open in Safari) but hadnt looked it up in NEC yet. thanks Dennis!
> 
> this is what came up first.. some concrete forum..
> "Aluminum reacts with the alkalis (OH) found in portland cement concrete. When these two chemicals are combined, the reaction produces hydrogen gas. This is why, when the reaction occurs in wet concrete, you'll notice tiny bubbles coming to the surface of a slab."


No problem... Heading out your way this weekend to visit my son in Asheville and to get a look at the tress. I hope they are in good color this year


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## Cincycaddy (Sep 18, 2014)

My take is just because there is rebar in the slab doesn't make it an ufer.


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## theJcK (Aug 7, 2013)

first job i ever started was in a three story hotel made of that puffy concrete they called Hebel. routed lines in that stuff to lay pipe with nail-straps. still hate it. quick lesson.. newbies get the router and dusk-mask. ::yuck:: never dealt with it since.. heard its bad to hold moisture and promote mold, years afterward. 

yea probably another week or so to be honest for peak to hit us . theres a little color but ive been working in Cherokee the most right now.. been a few weeks since i was in Aville.


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## Dennis Alwon (May 9, 2009)

Cincycaddy said:


> My take is just because there is rebar in the slab doesn't make it an ufer.


 That is true as the slab is not where you connect the ufer. Generally we are talking about rebar in the footings and the rebar must be at least 20' long and 1/2" diameter or larger


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## cavie (Sep 12, 2014)

Dennis Alwon said:


> That is true as the slab is not where you connect the ufer. Generally we are talking about rebar in the footings and the rebar must be at least 20' long and 1/2" diameter or larger


 And if it is, in Florida you WILL use it for UFER ground no matter what your opinion is. The rebar will not be in contact with the dirt. The wire will be copper. The connection may be in the concrete or turned up above ground in a dry accessible location.


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## Dennis Alwon (May 9, 2009)

cavie said:


> And if it is, in Florida you WILL use it for UFER ground no matter what your opinion is. The rebar will not be in contact with the dirt. The wire will be copper. The connection may be in the concrete or turned up above ground in a dry accessible location.


You Floridians are nuts. So Cavie, why would you enforce a ufer connected to rebar that is not in the footer? If it is in a slab the slab may not even be in the ground-- what a waste.

BTW, welcome to the wild side...


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## cavie (Sep 12, 2014)

Dennis Alwon said:


> You Floridians are nuts. So Cavie, why would you enforce a ufer connected to rebar that is not in the footer? If it is in a slab the slab may not even be in the ground-- what a waste.
> 
> BTW, welcome to the wild side...


 NO NO. I was agreeing with you. Must be in the footer.
:thumbsup:


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## Dennis Alwon (May 9, 2009)

cavie said:


> NO NO. I was agreeing with you. Must be in the footer.
> :thumbsup:


Good I thought you had gone over to the dark side. :thumbsup: :laughing:


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