Primer required?

[doug boardley]

if your chipboard is just sat on your insulation and there is no joists secured to your block and beam floor, and therefore no fixings in your chipboard to the joists to anchor everything to the b&b floor, then it's a floating floor, so you're going to get a lot of bounce and movement within the floor.This will lead to tiles cracking and de-bonding whatever adhesive you use imo

 

[The Legend; Phil Hobson RIP]

How did I miss that floating floor 😳 The man who never made a mistake, never made anything:yikes:

 

[Scholester]

So is there no deflection in Insulation boards used under the UFH? These are a polystyrene board so not solid by any means.
I am now really worried that I am doing completely the wrong thing having bought all of the kit!!!