Rebar as CEE - lap splice required?

Status
Not open for further replies.
kwired said:
What is in the photo to use as a reference to determine the size of anything?

We have no idea what the width of the trench is, and have no known objects to compare sizes to. Asking the OP what size the rebar is, is acceptable, but telling him what size it is with no supporting evidence is not right.
Click to expand...

I believe if we look at the tie wires if they are common bailing wire then these rebars are at least ?" in diameter, the vertical rod looks as if it is a little larger.

kwired said:
I see no problems here, and the picture is exactly what I see a lot of the time.

The vertical pieces are driven into the ground, not for use as grounding electrodes, the concrete guys could care less about that, they are used both as vertical reinforcement of the concrete and as a place to tie the horizontal bars to for positioning them where they want them in the pour. IMO your GEC needs to tie to a full 20 foot piece of bar, meaning that it can not tie to any of the vertical bars if they are less than 20 feet long, or if they would happen to be above grade when finished.

Some people don't feel this way, and some inspectors would let you tie to a 6 inch piece as long as it is tied "with the usual ties" to at least 20 feet somehow. I can kind of see where that comes from, but if presented with what we see in the picture why not tie to a horizontal bar instead of a vertical bar? It takes pretty much the same effort and removes any doubt of whether or not the vertical piece is acceptable.
Click to expand...

The code posted in post 7 clearly allows for multiple rods tied together to form a 20 foot rod, but I myself do not feel that the cross tied rods meet the intent of "usual steel tie wires" or "other effective means" if we think logically we know these very minimal connection points will not last very long, but then again how long will uncoated rebar last in concrete in damp ground???

250.52(A)(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 electri-
cally conductive coated steel reinforcing bars or rods of
not less than 13 mm (1⁄2 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
Click to expand...

Wow I'm a slow poster
 
Last edited:
George Stolz said:
Ignoring the size of the rebar (which we don't know), I'm with Rob and others on this. There is nothing in the NEC to prohibit a perpendicular lap from forming the connection to the CEE. It shouldn't matter anyway.
Click to expand...

Hi George,

I agree with you if the vertical rebar is considered having a 24" lap.
 
George Stolz said:
Ignoring the size of the rebar (which we don't know), I'm with Rob and others on this. There is nothing in the NEC to prohibit a perpendicular lap from forming the connection to the CEE. It shouldn't matter anyway.
Click to expand...

Yup, the issue is that the code wording is vague, merely stating that multiple pieces tied together can give us the minimum of 20' It doesn't specify how many pieces, vertical or horizontal, perpendicular, lap, etc. If you were to use a 20' piece of bare #4 then the wording is more specific.
 
RBJ, the IRC is concerned with structural soundness in requiring a 24" lap between rebar. Our "accessory" piece giving us connection to the CEE after the pour is not governed by that, AFAIK. The NEC (concerned with electrical connections) puts no 24" lap stipulations on the installation, so a 24" lap is not required for us, IMO.
 
kwired said:
What is in the photo to use as a reference to determine the size of anything?

We have no idea what the width of the trench is, and have no known objects to compare sizes to. Asking the OP what size the rebar is, is acceptable, but telling him what size it is with no supporting evidence is not right.
Click to expand...

The code says to use 1/2" rebar now it gives a length to use and it generally says how to apply it. It doesn't say
that it won't work in a mesh of any size or shape.

I don't see a ground CEE or the proper size that it's attached to, OK? Forgive my kindle!

Oh and for everyone else as a reader or as a poster, please continue to express your opinions within the guidelinesof this FORUM! Please also don't be affair to state an opinion in a post, question what you see and seek out the
correct answer, whether it's given here correctly or not.
 
Jude, please slow down and read your posts before submitting them. They're a little incoherent, and it may be adding more than a little confusion. I'm not trying to be rude; I think your kindle might be substituting words on you, causing incoherence.
 
George Stolz said:
RBJ, the IRC is concerned with structural soundness in requiring a 24" lap between rebar. Our "accessory" piece giving us connection to the CEE after the pour is not governed by that, AFAIK. The NEC (concerned with electrical connections) puts no 24" lap stipulations on the installation, so a 24" lap is not required for us, IMO.
Click to expand...

The cement subs agree. rbj
 
cadpoint said:
The code says to use 1/2" rebar now it gives a length to use and it generally says how to apply it. It doesn't say
that it won't work in a mesh of any size or shape.

I don't see a ground CEE or the proper size that it's attached to, OK? Forgive my kindle!

Oh and for everyone else as a reader or as a poster, please continue to express your opinions within the guidelinesof this FORUM! Please also don't be affair to state an opinion in a post, question what you see and seek out the
correct answer, whether it's given here correctly or not.
Click to expand...

I'm just saying don't be so eager to shoot down something you have no evidence of.

I see nothing wrong with asking OP if that is at least 1/2 rebar, but you pretty much insisted it is not with no references in the photo that give us any clue as to the size of anything visible in the photo. You then tell us it is likely masonry block mesh. How much block mesh have you seen that is not welded together vs wire tied together? I can see the tie wires pretty clearly in the photo. If you are viewing on a miniature monitor, IMO you have less business making comments on the size of things, you can ask, but you just can't tell what is there.
 
How can we tell the difference between the photo showing a 1" rebar in a 12 inch wide trench vs a 1/2" rebar in a 6 inch wide trench, and different zoom levels, with no known sized references in the photo?

Just put something simiple like a quarter in the photo and you have a reference to determine size.
 
I don't see a requirement in the code language to require a lap splice, bor do I see 'rebar' defined.

Before we get all wound up in splitting hairs, just what is a 'concrete encased electrode?' As I see it, it is the entire assembly that is the electrode, and not just the metal portion. When you put a "Ufer" in a slab, you make that entire slab your electrode.

Only by this model does the plain language of the code make sense - that ordinary tie wires are sufficient.

Indeed, there need not be any rebar at all- a copper wire coiled about where it enters a plain concrete slab would meet the reuirements for a CEE. In like manner, the rebar used need not be straight.
 
renosteinke said:
I don't see a requirement in the code language to require a lap splice, bor do I see 'rebar' defined.

Before we get all wound up in splitting hairs, just what is a 'concrete encased electrode?' As I see it, it is the entire assembly that is the electrode, and not just the metal portion. When you put a "Ufer" in a slab, you make that entire slab your electrode.

Only by this model does the plain language of the code make sense - that ordinary tie wires are sufficient.

Indeed, there need not be any rebar at all- a copper wire coiled about where it enters a plain concrete slab would meet the reuirements for a CEE. In like manner, the rebar used need not be straight.
Click to expand...

250.52(A)(3) describes what NEC considers a CEE.

(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 (? 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.
Click to expand...

I still think you need 20 feet of horizontal (qualifying) metal in the concrete, and I don't believe just any slab qualifies either, must be the "foundation or footing"
 
Gregg Harris said:
Darren, when you state, "will be raised vertically" are you refering to both the vertical and horizontal re-bar, or just the verticall?

I would conscider your idea a better design to have a 90 degree bend and multiple tight band wire to be a better mechanical connection.
Click to expand...

The entire rebar "ladder" grid will be raised as one piece, prior and during the concrete pour. The vert and horizontals will remain in the same orientation to each other.

Not exactly code compliant I know, but a concession we have made administratively for residential construction only.
 
gndrod said:
Hi Darren,
Thanks for the update. You did good. Just one more burning question. What brand of conductive paint is that on the rebar?
Click to expand...

The kind that gets scraped off before the clamp goes on. We had a terrible time keeping the framers or flat work guys from bending or cutting off the bar, so we have the paint it a bright color, to hopefully save it til later!
 
Darren Emery said:
Next time - I'll try to get a reference object in there!
Click to expand...

Hey, I'm not the one that insisted that your rebar was less than 1/2 inch, I just kept saying we really can't tell in the photo what the size of anything is, even thought it wasn't really a direct issue with the question in the OP. We never go off in semi related tangents here:)
 
Darren Emery said:
The entire rebar "ladder" grid will be raised as one piece, prior and during the concrete pour. The vert and horizontals will remain in the same orientation to each other.

Not exactly code compliant I know, but a concession we have made administratively for residential construction only.
Click to expand...

I would have guessed #4 bar and I would have guessed that this whole install is incorrect. Now the fact that you say they're going to lift it, yeah, maybe, once that concrete gets in there it's pretty tough to pull that up.
 
Status
Not open for further replies.
Top