I know of no NEC requirement to locate a ground rod 2’ from a foundation. UFER grounds are in the foundation.
You could drill a hole through the concrete and set the rods there. 2 rods with no less than 6’ spacing. Or you can run the wire around the house to the grassy area with no need to increase the size.
You could drill a hole through the concrete and set the rods there. 2 rods with no less than 6’ spacing. Or you can run the wire around the house to the grassy area with no need to increase the size.