Meant to be in the above post.
(c) Concrete-Encased Electrode. An electrode encased by at least 2 in. (50.8 mm) of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 20 ft (6.1 m) of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than ?-in. (12.7-mm) diameter, or consisting of at least 20 ft (6.1 m) of bare copper conductor not smaller than No. 4. Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means.1
That part might get you
He has 25' caisons I see this as a better UFER than 25' 1' below grade. Just my opinion though.Is it permissable to install a Ufer ground vertical rather than horizontal? The house where the ground will be installed will have caisons poured in place, 25' down.
yeah, they added a few words that help him out in this situation. I was reading 05'(3) Concrete-Encased Electrode. An electrode encased by at least 50 mm (2 in.) of concrete, located horizontally near the bottom or vertically, and within that portion of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 6.0 m (20 ft)
This is from the 08 a vertical 1/2" rod should be ok you could have 5-four foot sections in five different caisons and bond them together.IMO