If I understand correctly, when using a monolithic slab (where the footers and slab are poured as one piece), the vapor barrier is installed under the slab and the footers.
The NEC does not consider concrete that is over a vapor barrier to be in direct contact with the earth. ).
Are there any common practices or workarounds that are code compliant and used?
Note: I don't mean using a different grounding method, or skipping a vapor barrier. I'm asking if there's some clever way to get enough of the footer to contact the earth while still protecting the slab from moisture. Or something else along those lines.
NEC 250.52 (3)
Concrete-Encased Electrode. A concrete-encased electrode shall consist of at least 20 ft of [...] One or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 13 mm (1/2 in.) in diameter, installed in one continuous 20 ft length, or if in multiple pieces connected together by the usual steel tie wires, exothermic welding, welding, or other effective means to create a 20 ft or greater length.
Metallic components shall be encased by at least 2 in of concrete and shall be located horizontally within that portion of a concrete foundation or footing that is in direct contact with the earth or within vertical foundations or structural components or members that are in direct contact with the earth. If multiple concrete-encased electrodes are present at a building or structure, it shall be permissible to bond only one into the grounding electrode system.
Informational Note: Concrete installed with insulation, vapor barriers, films or similar items separating the concrete from the earth is not considered to be in "direct contact" with the earth.