Is this ok for tiling a chipboard bathroom floor? Fix 6mm Hardiebacker cement board onto the chipboard with screws and rapid setting flexible adhesive, then fix the tiles with a similar adhesive and grout with a flexible grout. The chipboard is already screwed down and the tiles are 45cm x 45cm porcelain. I dont want too great a step into the room.

sounds fine as long as the chipboard is quite stable

Thanks very much. Once I've put the Hardie boards down, can I walk over it straight away and how soon before I can start tiling?

A good time for a brew, then get back to work

If you have glued and screwed the cement boards, they ain't going anywhere so as WB says "have a brew and away you go".

Remember to wash the dust off the cement boards before you start mixing your addy up, no need to prime tho' .

Thank you both.