[TowerTalk] Grounding tower

[Jim Lux]

On 1/4/14 5:42 PM, Mike Fahmie wrote:
> I'm putting up a HDX572.  Digging the hole has been quite a job,
> hardpan was encounter a few feet below the surface and it was
> alternating jackhammer and backhoe work for two days to get close to
> the specified depth.
>
> Now, I'm wondering if I'll be able to drive ground rods into that
> stuff!  I have a impact driver with the appropriate driver head but I
> need a 'Plan B' if, as I expect, the rods won't go in.  I can imbed
> some rods or heavy gauge wire into the concrete (ala Ufer ground) but
> have heard that if the tower takes a strike the moisture in the
> concrete could flash into steam and fracture the concrete.
>

Nope.. no flash into steam.  Your situation is what the Ufer invented 
the concrete encased grounding electrode for.  20 ft of bare copper wire 
of the appropriate size (AWG4) , or bond to the rebar (which has to be 
20 ft long, minimum) .  From a ease of installation standpoint, I think 
the copper wire approach is easier.


http://www.nh.gov/jtboard/050909_concreteencasedelectrodes.pdf is a nice 
summary from New Hampshire