Hardie Board on 18mm ply and shower cubicle question

[carlsbergy]

i would appreciate a Bit of advice please as there is conflicting views on the site.

I have laid 18mm wbp ply on a bathroom floor after ripping up the old chipboard floor.

- should I use 6mm hardie boards on the floor and are they stuck to the ply floor with tile adhesive and screwed? Also do I pva the ply first?

- I have also build a 800mm shower cubicle with 12mm hardie board around the tray. Do I need to tank the hardie board cubicle or do I tile straight onto the hardie board?

Thanks in advance

 

[vinn]

Try and keep PVA out of bathroom walls and floors - only use the powdered tile adhesive and screws to fix the Hardie boards.
Fix around the wet walls according to Mfr's instructions - typically you screw & tape the boards without the need to tank.
Given that you have DIY built the cubicle I'm sure that you are aware that the walls must be plumb, and have perfect 90 degree inside corners.