ECN Forum Forums Code Related Discussion NEC & other Code issues Mass Ufer rule

Look at 680.26(B)(1)

No ground rods are required if you use a concrete encased electrode.
Don

Several years ago, my area went to concrete-encased electrodes on all new construction. I don't know how it is usually done, since I have rarely been involved in that phase of the job and now I generally don't do new construction at all.

For the past year, I have been using a type of concrete-encased electrode that has been recommended to me by several local AHJs, and that is due to be adopted as the standard for existing construction.

I dig a hole 30" deep and 24" diameter, and place 25' of coiled bare #2 Cu at the bottom. Add a bag of Quikrete, mix in water, then backfill. One AHJ advised me to leave the bag on the ground nearby, with a hose available, so he could pour it in himself after inspection.

I started using this method on the west side of town, where driving ground rods is frequently close to impossible. Word is ground rods will soon be eliminated altogether.

You would have a hard time convincing any AHJ around here he was mixing your concrete.

Alan- I agree with you. We are still on the '02 code here in Michigan so we haven't been pushing the concrete encased electrode yet but I would agree with you that all the rods in all the concrete are not automatically electrodes. If that's the case, we have a major problem on our hands.

This is not a Mass rule the use of the concrete encased electrode is a NEC requirement that is not amended by the Mass Board of Fire Prevention.

The letter that I-wire posted was circulated by the chair of the Mass Code Advisory Committee in an effort to coordinate the inspectional process between the building commissioners and the inspectors of wires.

As was mentioned if the rod is not in the pour this electrode is not required to be established although it may!

Greg,

Here in NJ the building inspector checks for the footing ground and it is only required on new buildings. Also as someone else said, the whole piece of rebar has to be encased otherwise it isn't rebar and the BI will fail you. Also in this state you do not need ground rods if you have a footing ground but some AHJ's will still ask for it, even though they are not suppose to.

Should the electrical industry quit messing around and just require 20 foot of # 4 and not rely on other trades to do our grounding for us ?
We had this whole agruement in the 1920's with plumbers about using their water pipes.
I suggest that we just put in the wire and not connect it to any thing except the earth.

Alan--

Alan, I would say you want the rebar because a couple hundred feet of rebar is a lot better than 20 feet of copper. It makes the whole footer a ground electrode instead of just 20 feet. If we really thought concrete alone was a good conductor we would just be using a 20' wire in a pool.

BTW we don't seem to mind steel workers building our electrode when it is building steel

[This message has been edited by gfretwell (edited 12-12-2005).]

[This message has been edited by gfretwell (edited 12-12-2005).]

I showed up on one job to do the temporary service and found the rebar in place and the concrete guys just waiting for the mud to be delivered. I asked them to stub up a piece of well tied rebar out of the footer and coat the last several feet of it with the foundation water proofing cement they had on site. They acted like I was crazy but they did it. It measured a lot lower than the thirty feet of number two that was used on the house next door. I have read somewhere that the steel does better in the footer than the bare copper does. Is galvanized rebar readily available? Will it help with the corrosion problem on the stub up. Galvanized ground rods are installed all the time so I presume that the galvaneal coating is reasonably conductive.
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Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison