Around here, we aren't even allowed to use rods anymore. West of I-35, odds are you can't drive it no matter how hard you try, and east of I-35, you can drive it, but in the summer when the soil dries up, the clay will shrink and there will be an air gap around the rod.
For new construction, we have to do a u-fer. For upgrades (90% of my work), we have to use a plate electrode. We automatically rent a chipping hammer, whether we need it or not.
