We're doing a retiling job on a tub surround. I have demoed the old tile and the drywall behind it. I have half-inch hardibacker to replace the old stuff, but it looks maybe an eighth of an inch less deep than the old stuff. I am wondering if that will be a problem where the hardibacker meets the drywall left behind, outside of the tub surround area. If so, what would the solution be to that? Is there an easy way to take care of it with end or bullnose tiles? (We have not selected the tile yet.) Any suggestions? Thanks much.