[TowerTalk] Rebar Cage Question

[jimlux]

Dick Green WC1M wrote:
> A Ufer ground doesn't necessarily call for a welded rebar cage. The NEC code
> doesn't require it, and there have been several studies showing that
> properly wired rebar provides sufficient conductivity. However, it's
> possible that welding is required by the buiding codes in some
> jurisdictions, so you should check with your local code officer.
> 
> FWIW, my local building inspector required a Ufer ground. I wired the rebar
> cage and used high-quality aluminum clamps with conductive grease to attach
> three ~50' pieces of 1/0 stranded ground wire to the cage. 

Folks should be aware that there's a lot of discussion and variation 
among what the local officials will want (notwithstanding what the NEC 
allows)..

There's a big running dispute about whether its ok to just bend the 
rebar up and have it protrude through the concrete or whether one should 
do the clamp and wire technique.  One faction says that the stub up 
approach is better because you can SEE the connection to the rebar after 
the pour is done, and that the clamp won't be disturbed by the pour. 
The other faction says that the concrete protects the clamp and that 
having steel rebar protruding from the concrete is a fundamental evil.

Then, there's a whole other set of practical issues having to do with 
inspections.. If you use the rebar vs the copper wire, it might change 
who does the inspection.  Do you need to get the electrical inspector 
out? Or is the foundations guy/gal ok?  The bent rebar stub up probably 
doesn't need the electrical inspector, who will come by later to check 
that clamp you're going to put on.

And then there are myriad interpretations about the "all available 
grounding means shall be bonded" requirement.  Does that mean that if 
there is metal pipe, you have to connect to it?  What if it's 
preexisting? What if it's a rotting old rod that someone pounded in 30 
years ago?  on and on and on.

Clearly, you want to have a friendly relationship with the man/woman 
with the pen in their hand.<grin>

Jim