My "Ufer" install is a little more involved. I take a piece of 34 solid copper, at least 30ft. long, and place it so that at least 20ft is alongside the rebar, with the remainder coiled up above the pour, near where the service will be.
The wire in the pour is attached to the rebar in at least two places; I use split bolts for this. I also string out the wire in a straight line, along the rebar; leaving a coil in the concrete just doesn't seem right to me.
