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Thread: Ufer rebar
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07-25-2014, 05:07 AM #1
Ufer rebar
Stilt home foundation with piers and continuous bond beam; running 5/8 rebar around perimeter. Question: How is ufer rebar attached to run? Are rebar ties sufficient or should it be welded.
And is ufer enough or do I need additional ground rod as well. If I'm missing any elements; please fill in the blanks. Thanks
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07-25-2014, 09:44 AM #2
Re: Ufer rebar
Minimum 20 feet of rear - sounds like you have that
Regular steel tie wires are okay
GEC is clamped to the rear with a clamp which is listed for CE (concrete encased), Rebar (and size of rebar), usually will also have a paper tag stating it is listed for every use, is a substitute for aspirin, and stops the aging process, etc
Typically will be cast brass or bronze with SS or brass screws.
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07-25-2014, 10:40 AM #3
Re: Ufer rebar
Jerry, thanks, but still not clear on this. I want to bend rebar (ufer) at right angle, attached to one of two 20 foot sections in the bond beam, then route this ufer above grade where I will attach ground clamp and ground wire. Also; how long should the section of the ufer be as it lies along the 20 footer in the bond beam. Does this all sound correct?
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07-25-2014, 12:59 PM #4
Re: Ufer rebar
The UFER needs to be in contact with the earth. How would being installed in the bond beam meet this?
https://www.google.com/url?sa=i&rct=...06404711414460
All answers based on unamended National Electrical codes.
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07-25-2014, 01:16 PM #5
Re: Ufer rebar
IMO the concrete needs to be in direct contact with the earth, not the rebar.
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As long as you have 20' or more rebar wire tied together you are good to go.
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As long as you have 20' or more rebar wire tied together you are good to go.
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As long as you have 20' or more rebar wire tied together you are good to go.
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07-25-2014, 01:22 PM #6
Re: Ufer rebar
I think I should be calling it a grade beam as it runs from pier footer to pier footer and is below grade. Sorry bout that. Also, still wondering if I'll need an additional and typical ground rod. This is for a personal home that I'm building. I've done others but never did the foundation before, always hired it out. Thanks
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07-25-2014, 02:01 PM #7
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07-25-2014, 02:31 PM #8
Re: Ufer rebar
The NEC does not require another electrode if the cee is used. If another is present they all need to be bonded together.
To Brad, I agree, I was thinking of how to word that better.
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07-25-2014, 02:40 PM #9
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07-25-2014, 03:28 PM #10
Re: Ufer rebar
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07-25-2014, 07:04 PM #11
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07-25-2014, 07:54 PM #12
Re: Ufer rebar
Maybe other places (I've seen posts where that is accepted in Texas), but I have not seen anyone approved that in Florida - the concrete encased electrode is the steel in the concrete, the rebar sticking up is not an appropriate GEC.
Now, if one wanted to attach the GEC to a vertical stub up of rebar, and then encase that vertical stub up in concrete like the rest of the concrete encased electrode, then it would still require a clamp listed for use to be encased in concrete.
And, to answer Mark's other question/statement, it is not sufficient to simply have 20 feet or more tied together, it needs to be 20 feet long. running a piece around the inside of a 4-1/2 foot by 4-1/2 footing (20 feet of rebar) is not going to cut it.
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07-25-2014, 08:20 PM #13
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07-26-2014, 06:26 AM #14
Re: Ufer rebar
The 2014 NEC has a change in it that does allow this method.
From the 2014 NEC
250.68(C)(3)
A concrete encased electrode of either the conductor type,reinforcing rod or bar installed in accordance with 250.22(A)(3) extended from its location within the concrete to an accessible location above the concrete shall be permitted
This has been an accepted practice in many jurisdictions across the US for many years now. Maybe not Florida but many other areas.
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07-26-2014, 06:31 AM #15
Re: Ufer rebar
I remember reading somewhere about the rebar sticking out of the footer being accepted even though it is not concrete encased. I think the debate started due to word parsing. It really didn't make sense that if the required amount of rebar was in the footing that you could not use the same bar outside of the footer. If you took two 20 foot bars and tied them together but left a stub of a couple of foot out it was unacceptable simply because the stub was not encased.
To Jerry, why are you saying the pier with 20 foot of bar is no good?
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Thanks for posting that Jack. I couldn't remember if that was from the continuing Ed of the IAEI or somewhere else.
All answers based on unamended National Electrical codes.
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07-26-2014, 06:55 AM #16
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07-26-2014, 07:06 AM #17
Re: Ufer rebar
Thanks everyone for the help but still not picturing it; I just want to have it correct for the county inspector when he shows up. I've got 160' feet of grade beam connecting 16 piers with two 5/8 running rebar. I want to use a ufer but not sure how to install it. I know there will be a stub out above grade where I can connect the GEC with appropriate clamp. Its the actual piece of rebar that I will use from the two parallel sections in the grade beam to above grade. Should it be a 20 footer section already installed with a right angle going above grade or can I just use another shorter piece bent and set along side (tied) to one of the two parallel sections and then routed above grade. If the shorter piece is acceptable; how long should it be where it is tied along an already installed piece of rebar.
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07-26-2014, 07:39 AM #18
Re: Ufer rebar
As long as the connection is secure I don't see the difference if the stub is part of a full bar or just a couple of feet.
All answers based on unamended National Electrical codes.
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07-26-2014, 07:42 AM #19
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07-26-2014, 11:17 AM #20
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07-26-2014, 05:19 PM #21
Re: Ufer rebar
Keep in mind that the question came from Florida and Florida is stuck on the 2008 NEC until the new code becomes effective later this year.
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As long as there are not two 10 foot long pieces tied together in a bundle - that is only 10 feet in length even though there is 20 feet or rebar there. Otherwise one could tie 20 one foot pieces of rebar together and claim to have 20 feet of rebar ...
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07-26-2014, 06:24 PM #22
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07-27-2014, 08:21 AM #23
Re: Ufer rebar
Brad,
I can ... when needed to represent the extremes to show the logic missing in some thinking.
The code wants a 20 foot long concrete encased electrode - minimum.
Putting 20 feet of rebar in a 5 foot by 5 foot pad footing does not equate to a 20 foot long piece of steel ... to make that difference obvious I simply chopped the 20 feet of rebar into 1 foot pieces ... hey, there is 20 feet of rebar there, right?
It's a tough job, but someone has to do it.
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07-27-2014, 01:14 PM #24
Re: Ufer rebar
Jerry, I am not seeing how someone could reject a 20 foot bar bent into a 5 foot square. The required amount of bar is accounted for and the code does not specify that the bar must be straight or cannot contain bends.
All answers based on unamended National Electrical codes.
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07-27-2014, 01:43 PM #25
Re: Ufer rebar
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07-27-2014, 01:57 PM #26
Re: Ufer rebar
JP, would you accept a flat steel plate buried I think it is 3 feet down with a built on clamp? That is allowed here, preferred quite often in fact.
John Kogel, RHI, BC HI Lic #47455
www.allsafehome.ca
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07-27-2014, 03:07 PM #27
Re: Ufer rebar
To Jerry, I don't see any valid reason to reject it. The 20 foot has been met.
All answers based on unamended National Electrical codes.
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07-27-2014, 03:22 PM #28
Re: Ufer rebar
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07-27-2014, 03:58 PM #29
Re: Ufer rebar
Just the one plate req'd for the service panel about 18" X 36" buried 2 or 3 feet down.
I found a pic for y'all to see, not that a pc is any more than an artist's conception. ufer.jpg
Oops I mean this one.
Last edited by John Kogel; 07-27-2014 at 04:07 PM.
John Kogel, RHI, BC HI Lic #47455
www.allsafehome.ca
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07-27-2014, 07:16 PM #30
Re: Ufer rebar
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07-31-2014, 06:03 AM #31
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07-31-2014, 06:51 AM #32
Re: Ufer rebar
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07-31-2014, 10:56 AM #33
Re: Ufer rebar
As we have very expansive soil in the Bay area, we see mostly pier and grade beam foundation systems where the grade beam spans between drilled, cast in place concrete piers. The grade beams are often required to have crushable material below them to allow expansion of the soils below and prevent uplift pressure on the bottom of the grade beam. In this case there may not be adequate contact between the soil and the grade beam to provide for adequate grounding, so we make sure that the ufer is well clamped to the pier reinforcement since the piers are well embedded into the ground. In any case, the adequacy of the ufer be checked by an ohms test.
By the way Mark, you never want to weld rebar unless you are using A706 grade rebar with preheating and Special Inspection. The grade of steel used in rebar is subject to brittle fracture after welding, unless done properly.
Thom Huggett, PE, SE, CBO
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07-31-2014, 11:00 AM #34
Re: Ufer rebar
Here in Washington State we require UFER/CEE (New Construction) or you get to do a ground ring/plate which most would not want to do.
The common practice here is to have the rebar extended above the foundation and then the GEC connected to that with a proper clamp. This connection has to be accessible.
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Here in Washington State we require UFER/CEE (New Construction) or you get to do a ground ring/plate which most would not want to do.
The common practice here is to have the rebar extended above the foundation and then the GEC connected to that with a proper clamp. This connection has to be accessible.
Don Hester
NCW Home Inspections, LLC
Wa. St. Licensed H I #647, WSDA #80050, http://www.ncwhomeinspections.com
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07-31-2014, 12:23 PM #35
Re: Ufer rebar
I can understand not wanting to do a ground ring once they realize what a ground ring actually is.
But not wanting to do a plate? That's easy enough to install, but ... if the CEE is present, and typically there is a CEE present, then it is required to be also as all electrodes which are present are required to be used and bonded together.
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07-31-2014, 02:06 PM #36
Re: Ufer rebar
There is no requirement for the resistance of the cee to be proven like a driven electrode.install it and you are done. No need to test or prove less than 25 ohms.
All answers based on unamended National Electrical codes.
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07-31-2014, 04:24 PM #37
Re: Ufer rebar
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