Tiling on a floating chipboard floor

[klunk]

Hi all,

I'm doing a small bathroom renovation for someone and the walls and floor are failing to bits with damp i can sort walls but the floor is chipboard which looks like its laid on 50m jablite its a flat in a old building floor proberly been there least 30 years, it looks like its all laid on top of a timber floor but i havent ripped it up all so hard to tell

Whats my best option for sorting this for tiling? any help apprecated

 

[klunk]

Well i have done a lot reading tonight, im going try convince him not to have a tiled floor and if he insists ill replace the chipboard with 18mm ply and overboard with hardibacker , the room is only 6' x 6' and a small bit less than 3 x 3 feet