The contractor is suggesting building a ground grid out of one continuous ground wire run back and forth, to be installed in the floor slab. Question: does the crossing of the wire need to be welded/crimped toegether in this situation?
ATT604
The ground grid needs to be connected at crossing locations because one of its main functions is to direct electric currents into earth under normal and fault conditions. If not connected, these points where ground wires cross would tend to heat up due to being a 'higher resistive' location in the grid. When you say floor slab do you mean a concrete floor? If so, someone else can provide better guidance on methods for grounding.