Need advise on laying glazed bathroom tiles

[johnscts]

I would like to remove a carpet and also remove the floor boards which are worse for wear. Can I replace with "Hardiebacker" boards and then adhere/seal glazed floor tiles direct to the hardiebacker boards - this is an upstairs bathroom and of course the boards will have to be (nailed/screwed) to the timber joists - many thanks in advance John

 

[flameport]

The thin Hardiebacker boards are intended to be fixed over an existing wooden floor.
If you want to fix directly to the joists, the much thicker Hardifloor must be used.

 

[johnscts]

Many thanks Flameport - you mentioned "Hardifloor " what thickness is this. Can I screw this direct to the joists - and can I just adhere/ glue cement this on to the hardifloor - B & Q said it can be layed but I was not aware that you payed it direct to floor boards. Appreciate this advice; is the hard igloos the same texture as the hardiebacker as I would like to cement tiles on top of these - would there need for water proofing
Kind regards John

 

[johnscts]

Just read my grammar and a wee bit confusing whether you are north or south of Hadrians wall. Trying to keep the bathroom floor as near to the same level as the corridor upstairs - I would like to take up the wood flooring and just put Hardi ..... whatever direct to joists - and then to cement ceramic tiles on top of this - but I have to be sure that the weight of traffic coming on that floor will not "crack " the tiles - obviously there will be a difference in the level between corridor floor and the bathroom (so a step up is unaviodable
Again any advise from any reader will be appreciated

 

[flameport]

Hardiefloor is 22mm, and has T&G edges. It's screwed directly to the joists in the same way that chipboard or other flooring panels would be.
The thinner Hardibacker is designed to be fixed over an existing wooden floor, as it is too thin to support any weight on it's own.

In both cases, tiles go directly on top using a suitable cement adhesive.

 

[johnscts]

Many thanks I read in my DIY Manual that 9mm external ply (don't know what the difference is between marine and external ply is) know doubt this will be cheaper - but the area is for a shower room and toilet (about 9ft x 5ft)
Lastly hardifloor is waterproof but if external ply is used does it need to be treated sealed - again Frameport many thank for your advise at this time
Kind regards John