Tiling onto an OSB floor?!

[Lakey]

Have a friend who is wanting to tile his bathroom floor which apparently is OSB (floor grade I assume) which is glued and screwed.
I am going to recommend either 6mm Hardie or 10mm Wedi/Jacko/Orbry, glued, screwed & taped, just want to make sure I am recommending the right thing. He did ask me for Ditra but I advised against as that is more for lateral movement.
Cheers

 

[CJ]

As long as the floor is ok/solid, I’d go 6mm Hardibacker.

 

[Cranbrook]

How thick is the osb?

 

[Lakey]

How thick is the osb?

18mm I think

 

[Cranbrook]

A test I use is to put my laser level on the wooden floor (I use a tripod) and then it on, I then walk around the room to see how much the laser lines are moving.. This helps me able to judge how much deflection is in the floor.. Dunno if this helps without experience mind..

Albeit 18mm osb overboard should be sufficient, if using a proper tile board correctly adhered to the osb