Adhesive thickness

[Etherglide]

Just picked up a kitchen floor with 800mm square polished porcelain. What thickness of ribs would you advise for the floor AND for the back of the tile. Previously laid a lot of 600mm porcelain but this is my first job with a bigger tile. Ill be using a levelling system with it.

 

[Paulg83]

12mm trowel and skim tile also