Hello folk, Going to tile my shower cubicle after cutting in a box for a hidden shower valve into the wall of the airing cupboard behind and facing with aquapanel. Do I need to tape and skim around the edge of the aquapanel to the cement render of the existing wall? The tiles we've gone for are full width of the shower so obviously wider than the box and vertically will join halfway up the "box" if that makes a difference? Thanks Jon