Sparky's Rebar?

Originally Posted By: psabados
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http://www.nachi.org/bbsystem/usrimages/more/IMG_4607.jpg.JPG ]


Looks like a few knock-out slugs and a connector.

[ Image: http://www.nachi.org/bbsystem/usrimages/more/IMG_4606.jpg.JPG ]

Just curious, is this what you Sparkies use for rebar. ![icon_rolleyes.gif](upload://iqxt7ABYC2TEBomNkCmZARIrQr6.gif)

Paul


Originally Posted By: jtedesco
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The rebar is required to be at least 1/2 inch in diameter and in “one or more lengths” totaling 20 feet in contact with the footing, or an unbroken 4 AWG can be used.


The reference is in the 2002 NEC.

Courtesy: www.nfpa.org

![](upload://lETd8NsHCJHuu2TDY6E80wglV6P.jpeg)


--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

Originally Posted By: Mike Parks
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Joe


Is there a min from the top??? Of the concrete.

I never thought of this before.

Mike P.


Originally Posted By: jtedesco
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Quote:
Concrete-Encased Electrode. An electrode encased by at least 50 mm (2 in.) of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth, .....


I will ask for some help from someone here who can tell us the required depth of a concrete foundation or footing.

I don't have access to a building code.


--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

Originally Posted By: gbell
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In Florida most residential footers are 18 inches. I have seen them up to 24 inches depending on the load they need to support. Most of our cement is 2500 to 3000 psi.



Greg Bell


Bell Inspection Service

Originally Posted By: Ryan Jackson
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The depth of the footings depends on the frost depth. Here in Utah, it depends alot on the elevation. One area that I inspect in is about 6,000 feet above sea level and gets probably 20 feet of snow every year. The frost depth there is 42".


As far as clearance to the top of the concrete, the ACI (American Concrete Institute) document 317 (I think) requires 3" of cover around rebar ![icon_smile.gif](upload://b6iczyK1ETUUqRUc4PAkX83GF2O.gif)


--
Ryan Jackson, Salt Lake City

Originally Posted By: Greg Fretwell
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If you go where it never gets below 0c the footer can be 8" deep, 12" wide (“bell footer” on a slab house). They put the plastic under the 4" deep slab but not the outer 8" rim of the “bell” where the footer is. You get 2 #5 rebar 2" to 4" up from the bottom. The current argument here is whether it is OK to simply turn up a piece of rebar for the EGC to connect to or whether you need a <typical> #4 copper with an acorn on it in the slab and stubbed up to the panel. The problem with that is they end up breaking it a lot, then you have nothing.


The argument is the turned up rebar, if it is exp[osed, will end up rusting off at the point where it exits the concrete.


What my wife’s company is doing is to bring up the stub into a core of a block that they knock a hole in. (paint the block green so it doesn’t get poured solid with the dowels!)


The sparky makes his connection after the block is done (that was when the damage happened) and then they seal up the block to prevent corrosion.


Originally Posted By: psabados
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Greg


If they seal the block over, then the connection is not visible correct? I'm assuming that the sealing process takes place after all required inspections are performed and the green light is given to proceed. How does one verify (visually) proper ground connection afterwards?

Paul


Originally Posted By: Greg Fretwell
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It is sealed after the electric rough, the stucco guy does it, they pack the hole with type S. They use an acorn clamp that is listed for encasement in concrete. The alternative is to put a mud ring in the wall and a blank cover but you still have the corrosion issue. If water collects behind the cover it can rust the rebar off.


Originally Posted By: psabados
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How about using a plastic or PVC sleeve, sliding it down, out of the way. Make the connection, pull the sleeve back up and fill it with a potting compound. Totally sealed then and water/chemical resistant. Forms something like a seal-off barrier, but the connection is in the mix.


Paul


Originally Posted By: Greg Fretwell
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It costs them about a quarter’s worth of stucco mud to seal it and less than a minute of the stucco man’s time. They are not going to buy potting and some plastic sleeve. You might even have an inspector asking if all of that is “listed”


The concrete encasement is.


Originally Posted By: dbozek
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Joe,


I might be wrong here but when placing a ground into concrete, would it not be required for that connection to be cad welded? Art 250 is always bonkers to me ![icon_eek.gif](upload://yuxgmvDDEGIQPAyP9sRnK0D0CCY.gif)


--
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

Originally Posted By: jtedesco
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Exothermic Welding Process or Irreversible Compression Type Connection

Courtesy: www.nfpa.org


--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

Originally Posted By: Greg Fretwell
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250.68 Grounding Electrode Conductor and Bonding Jumper Connection to Grounding Electrodes.


(A) Accessibility. The connection of a grounding electrode conductor or bonding jumper to a grounding electrode shall be accessible.


Exception: An encased or buried connection to a concrete-encased, driven, or buried grounding electrode shall not be required to be accessible.


*** You can bury the connection in a concrete encased electrode

250.70 Methods of Grounding and Bonding Conductor Connection to Electrodes.
The grounding or bonding conductor shall be connected to the grounding electrode by exothermic welding, listed lugs, listed pressure connectors, listed clamps, or other listed means. Connections depending on solder shall not be used. Ground clamps shall be listed for the materials of the grounding electrode and the grounding electrode conductor and, where used on pipe, rod, or other buried electrodes, shall also be listed for direct soil burial or concrete encasement. Not more than one conductor shall be connected to the grounding electrode by a single clamp or fitting unless the clamp or fitting is listed for multiple conductors. One of the following methods shall be used:
(1) A pipe fitting, pipe plug, or other approved device screwed into a pipe or pipe fitting
(2) A listed bolted clamp of cast bronze or brass, or plain or malleable iron


*** You can use a clamp if it is listed for concrete encasement


At least that is the way the AHJs read it here. YMMV if your AHJ's brother in law sells CadWeld kits ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif)


Originally Posted By: dbozek
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Thanx…


Been doin residential too long......god I miss the commerical days. Seemed to me it had to be cad welded....and seems I got dinged on that once in them commercial days ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) . Thanx for clearing that up.


--
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln