Ufers

[mbrooke]

Are UFERs required for dwelling units? Are they required for commercial? Around here there isn't a single home with a UFER, and close to 90% of commercial inspectors let is slide. But after reading article 250, it has me thinking I could be doing something very wrong.


I would think bonding rebar foundation is more important to grounding than ground rods, possibly even the water bond since the foundation is such a large conductive part of the building requiring equal potential.


Also, am I correct to say that with a UFER, other grounding requirements (such as 2 ground rods) become optional?

 

[GoldDigger]

Almost anything is better than a ground rod. They really form a ground of last resort when nothing else is available.
Under the NEC if a Ufer exists it must be used. And it exists if the rebar meets the requirement, even if no way was provided during the pour for you to connect to it.
In a few locations, by amendment, you have to create a Ufer/CEE period.
Especially in an area of dry or rocky soil, the CEE is the best chance you will have of a good ground.
I agree with your conclusion in the first paragraph, but in your favor proper bonding is more important IMHO than a solid earth connection for just about everything except a lost neutral.

And, yes, the ground rods become optional.

 

[Dennis Alwon]

Are UFERs required for dwelling units? Are they required for commercial? Around here there isn't a single home with a UFER, and close to 90% of commercial inspectors let is slide. But after reading article 250, it has me thinking I could be doing something very wrong.


I would think bonding rebar foundation is more important to grounding than ground rods, possibly even the water bond since the foundation is such a large conductive part of the building requiring equal potential.


Also, am I correct to say that with a UFER, other grounding requirements (such as 2 ground rods) become optional?

The ufer is required for both resi and commercial buildings but many areas don't enforce it. Basically if the means to connect to an electrode exists then you must use it. NC gets around it by saying that when the electrician gets there the electrode (rebar) is not accessible to you don't need it. I, personally, use it all the time unless my builders screw up. I generally have to stay ontop of the job and call them regularly to make sure they are not pouring the footing without my grounding electrode conductor.

 

[infinity]

It's enforced around here if the rebar qualifies as an electrode. It's almost always part of the footing inspection to make sure that it's installed. I once did a house where the footing inspector wouldn't let them pour until the concrete guy put in the GEC to the rebar, so the concrete guy runs over to home depot and buys a piece of #8 solid and a clamp and attaches it to the 3/8" rebar to pass inspection. :slaphead:

 

[Dennis Alwon]

It's enforced around here if the rebar qualifies as an electrode. It's almost always part of the footing inspection to make sure that it's installed. I once did a house where the footing inspector wouldn't let them pour until the concrete guy put in the GEC to the rebar, so the concrete guy runs over to home depot and buys a piece of #8 solid and a clamp and attaches it to the 3/8" rebar to pass inspection. :slaphead:

And technically he is not allowed to install the grounding electrode conductor.

 

[102 Inspector]

A #8 wire on 3/8" rebar would not qualify for grounding. It would require 1/2" rebar to meet the requirements. I would also check to make sure the connector is rated for deformed rebar.

 

[Dennis Alwon]

A #8 wire on 3/8" rebar would not qualify for grounding. It would require 1/2" rebar to meet the requirements. I would also check to make sure the connector is rated for deformed rebar.

Yes I think that was Trevors point. Look at the icon at the end of his post

 

[Nom Deplume]

The way I understand it is if there is rebar you must connect to it.
If the rebar is too small or nonexistent then it is not required but you can install 20' of bare wire and create your own UFER.

Do you have to connect to the rebar if you just install the 20' of bare wire? As if you didn't have a connector or cadweld.

 

[Dennis Alwon]

The way I understand it is if there is rebar you must connect to it.
If the rebar is too small or nonexistent then it is not required but you can install 20' of bare wire and create your own UFER.

Do you have to connect to the rebar if you just install the 20' of bare wire? As if you didn't have a connector or cadweld.

Why wouldn't you connect it to the rebar? If you already have 20' #4 in the footer than add a clamp and it is that much better. IMO if the rebar is there you must use it. I usually do both- 20' and connect to the rebar. Why? because I am a nut and if the connection even went bad to the rebar I still have the 20' in there

 

[bphgravity]

Try not to think of grounding from a performance standpoint. The performance of the grounding system is of almost no consequence on perhaps 90% of all installations. For those 10% or fewer installations where the performance of the grounding system may be of greater importance, there is almost no increased benefit of installing a grounding system above code minimum.

So, just look at the prescriptive requirements of Article 250 and try not to overthink it.

To answer your questions: No, No, & Yes.

No, concrete-encased electrodes are not required for dwellings. If a concrete-encased electrode happens to be present at a dwelling, then it must be bonded to the electrical service or other system that is required to be connected to the grounding electrode system. The same answer applies to non-dwellings. The code does not differentiate between occupancy types when it comes to grounding.

And yes, concrete-encased electrodes are not required to be supplemented with another electrode type.

 

[Nom Deplume]

The way I understand it is if there is rebar you must connect to it.
If the rebar is too small or nonexistent then it is not required but you can install 20' of bare wire and create your own UFER.

Do you have to connect to the rebar if you just install the 20' of bare wire? As if you didn't have a connector or cadweld.

Why wouldn't you connect it to the rebar? ...

My question was if you didn't have a connector, would the 20' be just as good since if you installed the 20' without rebar it would be acceptable.

 

[mwm1752]

It's enforced around here if the rebar qualifies as an electrode. It's almost always part of the footing inspection to make sure that it's installed. I once did a house where the footing inspector wouldn't let them pour until the concrete guy put in the GEC to the rebar, so the concrete guy runs over to home depot and buys a piece of #8 solid and a clamp and attaches it to the 3/8" rebar to pass inspection. :slaphead:

All he had to do was extend 1/2" min rebar from the footer steel to the wall & call the electrician prior to the wall pour -- Here we educate and inform so that the availiable electrode within the new foundation footer is connected to the service. While I agree it is not required, I have not seen foundation footers around here without min 1/2" rebar. With the rebar in place it is required. Lighting strikes happen frequently all over the world so I disagree that a grounding system performance is rarey tested. Code creates a minimum standard but the Mr.Ufer and the US Army came up with the best electrode for good reasons.

 

[Dennis Alwon]

My question was if you didn't have a connector, would the 20' be just as good since if you installed the 20' without rebar it would be acceptable.

It may be but there is usually a lot more rebar so my guess is that the 20' of #4 is not as good but IMO it would not be compliant if the rebar exists there.

 

[infinity]

My question was if you didn't have a connector, would the 20' be just as good since if you installed the 20' without rebar it would be acceptable.

If the rebar is 20' or longer you need a CEE but how you make one is up to you. Either use the rebar or lay in 20' of #4 copper or like Dennis does you could use both.


In my aforementioned scenario there were many things wrong, for one, as stated the 3/8" rebar cannot be used as an electrode so no CEE is required. Secondly the service was 200 amps so even if the rebar were 1/2" the #8 was too small. The fact that the footing inspector held up the pour because of his ignorance was the real story.

 

[mbrooke]

The ufer is required for both resi and commercial buildings but many areas don't enforce it. Basically if the means to connect to an electrode exists then you must use it. NC gets around it by saying that when the electrician gets there the electrode (rebar) is not accessible to you don't need it. I, personally, use it all the time unless my builders screw up. I generally have to stay ontop of the job and call them regularly to make sure they are not pouring the footing without my grounding electrode conductor.

I think that what Im seeing here. Even though nearly all foundations especially commercial qualify for this it never gets noticed or taken care of. Simply electrical gets done ling after the pour, no one assures rebar is exposed for bonding.


BTW, which code section lets you get around this?

 

[GoldDigger]

BTW, which code section lets you get around this?

None, AFAIK, for new construction. And in many areas inspectors will make you break up the concrete to get access to rebar.

 

[infinity]

I think that what Im seeing here. Even though nearly all foundations especially commercial qualify for this it never gets noticed or taken care of. Simply electrical gets done ling after the pour, no one assures rebar is exposed for bonding.


BTW, which code section lets you get around this?

It's required and there are no exceptions in the NEC. As Digger said get out the jack hammer.

 

[mbrooke]

It's required and there are no exceptions in the NEC. As Digger said get out the jack hammer.

Guess it does pay for itself to know ahead of time:happyyes:

 

[bullheimer]

here in WA all new buildings are required to have one. i have this issue now with a detached garage w/o any rebar access. he failed my two ground rods and pointed me in the direction of a ground ring. i am waiting till tomorrow morning to see what lies ahead. the building was built before the requirement hit July 1, so i am hoping that lets me out.

i am also hoping somebody will read me 250.50 out of a 2014 book to tell me if it's still there, which said i don't have to use the rebar if any demolition is required. that would probably put me back into having a ground ring. there used to, i believe, be wording to the effect that a ground ring could be only 20 feet of wire in the ground, but now i think that language is gone that is, a ring goes all the way around a building!!! i will have to ask mr lead inspector around here wtf he wants me to do.

 

[Curious nerd]

2014 250.50, "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." I believe WA has their own rules though. The ground ring definition is "(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."