Ufer ground

[tdebrum]

Have any of you seen where someone ran a ufer ground up a concrete wall,rebar is in footer but turned up ,in this case up a 9' concrete wall,so you would connect to rebar sticking out top of wall and your ground connection would be at top of wall.
I have not seen this before but am told this is how it's done.

 

[augie47]

That would be an acceptable method. The rebar extension is not supposed to be in contact with the earth and the connection needs to be accessible.

 

[Dennis Alwon]

I have done this once but I did not leave access. How do you leave access to rebar in a concrete wall? Imo that is no different than connecting to the the rebar in the footing as long as the rebar is connected to the rebar in the footing.

 

[kwired]

I have done this once but I did not leave access. How do you leave access to rebar in a concrete wall? Imo that is no different than connecting to the the rebar in the footing as long as the rebar is connected to the rebar in the footing.

I think he is saying rebar sticks out of top of wall and the GEC connection is not embedded in the concrete.

 

[kwired]

Also if the vertical wall is in contact with earth and have insulating covering (often waterproof coatings on basement walls disqualifies them) it can contain a CEE.

 

[tdebrum]

I personally don't think this is a good idea,if lighting were to find it way to this ground connection in the wall ,it could possibly crack 9' of concrete wall, maybe I'm wrong,like to hear more about it.

 

[Tulsa Electrician]

It's done all the time where there is basements. They leave a one foot piece sticking out the top so it can be bent over and and GEC attached. In that area it is required to stubbed out the top of the wall with in fifteen feet of the meter location or near the sump pump. They like the sump pump due that is usually in the mech room and the panel is also in that location as well. This area allows the MBJ to be in that panel as long as there is no more than 15' of service cable total from meter to panel.
Other wise it must be bent out side and GEC ran to that location.
This area also uses a different sizing rule and must use 250.66 which can exceed the #4 sizing
It always pays to ask local AHJ for admentents.

 

[tdebrum]

Where did you get that attachment ,what page in code book,or is that from a building code book.

 

[tdebrum]

250.66(A) thorough (C)
(B) describes connections to Concrete - Encased Electrodes

 

[Dennis Alwon]

It's done all the time where there is basements. They leave a one foot piece sticking out the top so it can be bent over and and GEC attached. In that area it is required to stubbed out the top of the wall with in fifteen feet of the meter location or near the sump pump. They like the sump pump due that is usually in the mech room and the panel is also in that location as well. This area allows the MBJ to be in that panel as long as there is no more than 15' of service cable total from meter to panel.
Other wise it must be bent out side and GEC ran to that location.
This area also uses a different sizing rule and must use 250.66 which can exceed the #4 sizing
It always pays to ask local AHJ for admentents.

This 15' of the meter is a local amendment not an NEC rule.

The fact that the rebar sticks out of the footing does not change the fact that the grounding electrode conductor doesn't have to be any larger than #4. It can be but it doesn't have to be. Perhaps when you say this area you mean in OK.

 

[roger]

I personally don't think this is a good idea,if lighting were to find it way to this ground connection in the wall ,it could possibly crack 9' of concrete wall, maybe I'm wrong,like to hear more about it.

Lightning protection system terminal drops run down concrete (and other construction) walls and are connected to a buildings GES all the time, this occurs at multiple locations so I wouldn't worry about it too much.

 

[tom baker]

I personally don't think this is a good idea,if lighting were to find it way to this ground connection in the wall ,it could possibly crack 9' of concrete wall, maybe I'm wrong,like to hear more about it.

How is that different from the typical connection in the footer?
What substantiation do you have for damage from a lightning strike damage in stem wall?

 

[James L]

Here in Kansas City the vast majority of rebar type is going all the way through the wall with a foot or two sticking out the top.

Only once or twice I've seen it sticking out between the floor and wall, indicating that it was turned out and up from the footing.

One time it was sticking out the foundation wall into the front stoop area, and it wasn't long enough to reach the top of the foundation wall.

I've never had an inspector demand an accessible ufer clamp.

 

[kwired]

Here in Kansas City the vast majority of rebar type is going all the way through the wall with a foot or two sticking out the top.

Only once or twice I've seen it sticking out between the floor and wall, indicating that it was turned out and up from the footing.

One time it was sticking out the foundation wall into the front stoop area, and it wasn't long enough to reach the top of the foundation wall.

I've never had an inspector demand an accessible ufer clamp.

It not required to be accessible if encased in the concrete. If not encased it must be accessible.

The piece you mentioned sticking out into front stoop area might not been intended for you to connect to as much as it was maybe intended to reinforce stoop to the wall.

 

[kwired]

It's done all the time where there is basements. They leave a one foot piece sticking out the top so it can be bent over and and GEC attached. In that area it is required to stubbed out the top of the wall with in fifteen feet of the meter location or near the sump pump. They like the sump pump due that is usually in the mech room and the panel is also in that location as well. This area allows the MBJ to be in that panel as long as there is no more than 15' of service cable total from meter to panel.
Other wise it must be bent out side and GEC ran to that location.
This area also uses a different sizing rule and must use 250.66 which can exceed the #4 sizing
It always pays to ask local AHJ for admentents.

They can make such local rules if they want to, but curious to know what their justification might be to run more than a 4 AWG to the CEE.

I think NEC has determined a CEE can't dissipate any more energy than a 4 AWG can deliver to it is reason why they don't require any more than 4 AWG as sole connection to a CEE. Same goes for rod and pipe electrodes except it is 6 AWG that is maximum conductor for sole connection to the rod or pipe electrode.

 

[Tulsa Electrician]

Yes they are local admentents to the NEC.

I did not want to imply it was per NEC, sorry if I made it sound like that.

Just found it interesting.
It was on a job in Kansas.

 

[tdebrum]

Cool

 

[tom baker]

They can make such local rules if they want to, but curious to know what their justification might be to run more than a 4 AWG to the CEE.

I think NEC has determined a CEE can't dissipate any more energy than a 4 AWG can deliver to it is reason why they don't require any more than 4 AWG as sole connection to a CEE. Same goes for rod and pipe electrodes except it is 6 AWG that is maximum conductor for sole connection to the rod or pipe electrode.

The reason Mr Ufer used a 4 AWG is it was readily available on the job site when he did the tests of its suitability. But he may of known about the maximum energy part you mention. I will review his IEEE paper

 

[James L]

It not required to be accessible if encased in the concrete. If not encased it must be accessible.

The piece you mentioned sticking out into front stoop area might not been intended for you to connect to as much as it was maybe intended to reinforce stoop to the wall.

That one in the stoop was low enough that it would have been in the dirt below the concrete

 

[texie]

Here in Kansas City the vast majority of rebar type is going all the way through the wall with a foot or two sticking out the top.

Only once or twice I've seen it sticking out between the floor and wall, indicating that it was turned out and up from the footing.

One time it was sticking out the foundation wall into the front stoop area, and it wasn't long enough to reach the top of the foundation wall.

I've never had an inspector demand an accessible ufer clamp.

The Ufer clamp either has to be encased in concrete or if the rebar extends out out the pour it has to be accessible.