Since this is a recent thread and relevant, I have a question related to meter box surface installation. I have a metal shed/shop and the spacing of the metal and it's vertical ribbing is such that there is no way to mount the box flat to the metal sheeting, which isn't a surprise. I was going to do two 5 ft legs of Unistrut and have to figure that mess out along with drilling new holes in the box but I saw someone use cut off PVC slices, about 1 1/2 inch tall as stand-off spacers in between the box and the wall. Would something like that pass a city inspection or is there any code wording that specifies spacer and mounting materials when you are offsetting a semi-flush mount setup? Seems like it would be a clean install solution, as opposed to having wood or strut hanging out and being overly visible.