advice on tanking floor

[merit]

trying to put right a wet room a previous tiler had installed ,that when i stripped it back i found that the floor hadnt been tanked,if you can beleive that.the existing tiles have been fixed on green chipboard so they hadnt stuck ,thus the tiles had popped.
i need to over board, so shower tray former needs to be raised,i was going to fix 6mm hardi ,then tank with wb1 or equivalent, bottom row of tiles off tape to wall and floors ect question is do ineed to prime hardi before tanking, and will this suffice, or any other alternatives ? ufh as well
thanks in advance

 

[Time's Ran Out]

If your green chipboard is well fixed and NO deflection, go with Ditra matting and you may find you will not have to raise the tray.

 

[Rich]

What a dogs dinner. A wet room tiled onto chipboard :mad2:


You shouldn't need to prime the hardie boards. Are you over boarding the old chipboard? If so make sure that it is not damaged and it must be screwed down good and proper, the Hardie boards will not be much use if the boards underneath them are not fixed down correctly.

 

[merit]

boards are fixed correctly ,the reason for hardi is the height issue, trying to keep it as low as poss ,john would the ditra or other matting stick ok to green eco chipboard ?

 

[Alan.P]

I've stuck plenty of Ditra down on green chipboard using flexi rapid over the last few years, never had a problem, touch wood lol