Hi,

I am confused about what to do about prepping my bathroom walls for tile. I have hardibacker in the shower area that the tile guy will cover completely with Hydroban, including the pan (there is no poly behind the hardibacker). The hardibacker joints will be thinset. The CBU/drywall joint was done with regular mesh tape and drywall mud by the drywaller. So it feathers onto the CBU, with a little bit in the actual wet area. Does that need to be removed or sanded down before the Hydroban goes on?

Also I am doing a tile wainscot on regular drywall. The drywaller got some mud and texture (light knockdown) a few inches down into the wainscot area. Does that have to be removed before tiling? Should the raw drywall wainscot area be primed or completely hydrobaned before the tile is installed? Does it make a difference whether thinset or mastic is used for the wainscot in the dry area as to whether or not it should be primed/hydrobaned? I am assuming that the wainscot area shouldn't be painted.

Thanks!