Cement Board Jointing and Tanking ? - Tile Advice

[1001charlie]

Please help. I’m about to tile a small two-sided shower area, 2.5m high and width 1.2m one way and 2m the other. Tiles are conventional ceramic
Substrate is 6mm Hardie Board glued and screwed onto original plywood to one side and plasterboard to the other.
Hardie recommend using their fibatape and an adhesive skim 150 wide over the board joints. I intend tanking the area using a Nassboards waterproof tanking kit including tanking tape etc. Do I use both, ie the Nassboards tape over the fibatape and adhesive skim or do I just use the tanking?

 

[Flintstone]

Just the tanking. I don't think 6mm Hardie is for walls. 6mm for floor, 12mm for walls.

 

[1001charlie]

Thanks Localtiler. Think 6mm is OK if it's over existing not just by itself on thestudding.