[TowerTalk] Rebar Cage Question

[Dr M J DiGirolamo]

Hi Dick,

  Thanks for your email.

  You're right, whether or not a rebar cage requires welding depends on
local codes and/or whose advice you listen to.  I worked mostly from the
information supplied by PolyPhaser and from doing my own research.  I
concluded it wouldn't hurt to do the welds (regardless of contrary opinions)
as it made sense to me and I had a friend willing to do the welding.  The
additional cost was negligible.

    Oh, MY, MY, MY!!  When you mentioned "ditch witch" my body began to
shake and hurt!!  My grounding system called for a 250' trench around my
house, as well as the 3 tower radials in my yard.  Every time I hit a tree
root or rock, I was tossed all over the place.  It was an experience I'll
never forget.  BUT, worse than that was the Cadwelding experience.  Using
the one-shots like you had, was a NIGHTMARE.  I guess I had the first batch
of new molds.  Also, the igniting powder broke loose and mixed with the
welding compound so there was nothing to ignite with, in most cases.  The
folks are Erico stood by me but it was still a nasty, nasty experience.
Here is a link to my photos.  There are a LOT of them and unfortunately,
they're not in any order.  Enjoy...

    http://s287.photobucket.com/albums/ll147/Apostle10/?start=60

73,

Mike DiGirolamo, W4XN

PS  You can read more about my experiences on qrz.com under my call: W4XN

    >-----Original Message-----
    >From: Dick Green WC1M [mailto:wc1m at msn.com]
    >Sent: Wednesday, December 10, 2008 13:20
    >To: 'Dr M J DiGirolamo'; towertalk at contesting.com
    >Cc: k4kyv at hotmail.com
    >Subject: RE: [TowerTalk] Rebar Cage Question
    >
    >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. I ran one
end of
    >each wire up through the clamp so that it extended above the tower base
by
    >about two feet. After the pour, these pigtails were attached to the
tower
    >legs, bonding the tower to the rebar cage (I have a pier-pin base.) The
    >other ends of the 1/0 wires extended out the side of the base hole and
were
    >coiled up during the pour. After the pour, I had a guy with a Ditch
Witch
    >dig three 48' trenches extending from the base and laid the 1/0 wire in
the
    >trenches. Then I pounded in 8' ground rods every 16' in each trench and
    >Cadwelded the 1/0 wire to each rod. Lots of work!
    >
    >You can see pictures of most of this on my website at www.wc1m.com.
Click on
    >"Big Tower Project" on the left, then click on "Pier and Anchors" or
"Ground
    >System".
    >
    >73, Dick
    >
    >
    >> -----Original Message-----
    >> From: Dr M J DiGirolamo [mailto:DrD at 2020.com]
    >> Sent: Wednesday, December 10, 2008 11:08 AM
    >> To: towertalk at contesting.com
    >> Cc: k4kyv at hotmail.com
    >> Subject: Re: [TowerTalk] Rebar Cage Question
    >>
    >> Don,
    >>
    >>
    >>
    >>    I built my cage from "weld quality rebar" and it was welded by a
    >> friend.
    >> My friend is a certified master welder at a nuclear power plant here
    >> in
    >> Virginia.  --- snip, snip, snip ---
    >>
    >> Mike DiGirolamo, W4XN
    >>
    >> Charlottesville, VA