ufer

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Re: ufer

I use it a lot in fiber optic regenerator stations. Cheap and effective. It is now required in the 2005 NEC as I understand, have not got the new code book yet :eek:
 
Re: ufer

Beware of what I think that picture is showing. That is rebar from the footing exposed. I'm sure your building inspector would not go for that. better to make the connection inside the concrete avoiding corrosion on the rebar.
 
Re: ufer

Ryan
The rebar shown is an extension of the structural rebar in the slab/footing.

I assumed this rebar was to be exposed outside. It would then be at , near or in the dirt. Being unprotected steel, the corrosion will travel inside to rot out the rest of the rebar. The first thing you would lose is your connection to earth.

Also the requirements in the UBC or I would think all building codes require a specific inch coverage of concrete to prevent corrosion of the steel. 3 inches to dirt and I think 1 inch to air.

That being said, if the rebar came up inside the building that would be a normally dry location and be ok.

I'm no expert in reinforced concrete, but that's what and why we have done here since I can remember. :D
 
Re: ufer

Been using #4 x 20' rebar for residential and lt commercial UFER's since 1972. Eliminates staked rod(s) cost and potential damage. Rebar must be set in trench foundation footing within 2" of horizontal (I used brick flat on stretcher-side as spacer) above hard pan footing with AHJ buyoff prior to pour. NEC 2005 [250.52(A)(3)

Eliminates cost of staked rod(s) and time to drive them in as compared to having GC lay in an extra #4 rebar. You'll have to be there to help while attaching wire ties to the form footing iron. Some AHJ require an inspection port to verify GEC clamp to rebar sticking out of stemwall.

Second method is to lay 20'x #4 AWG copper in footing 2" above hardpan with extra continuous length (i.e. 6'+ pigtail) long enough to reach distance into Main Service panel ground bus. Saves rod clamp.

Downside, must have early involvement (contract) with contractor before foundation, otherwise NEC 2005 [250.50] leaves open 2002 existing options.

rbj, Seattle
 
Re: ufer

The 2005 doesn't leave open any options. If there is steel in the footing, it must be used. If that means getting out a jack hammer than you have to get out the jack hammer.
 
Re: ufer

ryan,

Please humor me for a minute. "Alternate" is a better choice of words. Sorry....250.50 reads "that are present at each building or structure served shall be bonded to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used."
Please read the exception that supports that also. Am I wrong?

rbj, Seattle
 
Re: ufer

I think you are reading into it a little bit. Take a close look at the exception. It states that on an existing building you need not disturb the existing concrete. With that said, if it is a new building and the electrode is there, you are required to use it, even if that means disturbing the concrete.

I had a few conversations about this with Chuck Mello and Mike Johnston, both on CMP 5 for article 250, and this indeed is the intent. They want the Ufer used and they want it used on every job. :eek:
 
Re: ufer

I agree with you on that. So what I understand is that if the contractor doesn't allow for an exposed UFER and the forms are poured, then the EC better include in the bid on a jackhammer rental if a UFER is not spec'd in the plans. I feel it is in the hands of the AHJ at this point. The CMP are wise enough not to indelibly say UFER ground or else. I respect intent.

rbj, Seattle
 
Re: ufer

With that said, if it is a new building and the electrode is there, you are required to use it, even if that means disturbing the concrete.
Click to expand...
The structural engineer may have a problem with this. There is no way that I'd ever let one of my electricians cut into the structure to get to the rebar unless I had signed papers from a structural engineer with a PE.
Don
 
Re: ufer

If I were doing commercial building.More than likely their would be some kind of underground.I would be little more involved with project and install a #4 re bar 30 feet in nearest outside footing with bending into main switch section.
Or if I am not worried about the bid,I install 30 feet of 3/) copper also in to nearest footing.Keep in mind the re bar or the copper not to disturb soil.
I like to layout my switchgear and get the underground in first.
Southern Calf area.
Thanks Rick
 
Re: ufer

Rick,
For commercial work in this area, the footings are often poured before the bids are in on the electrical work.
Don
 
Re: ufer

Don,
You are probably right.I am the type of contractor that usually go after nrthese types of projects early,if I want them.The building inspector should get schooled on ufer grounding.Take care
Rick
 
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