DIY Related: Tiling onto suspended floor (bathroom)

[Ryaneb85]

Hi all, this is my first post, hope you can help out.

I'm redoing my bathroom from top to bottom. I am going to be tiling the floor, so while the room was totally empty I ripped the old floor boards out and laid down some 18mm Tongue and groove water resistant chipboard from wickes:

http://www.wickes.co.uk/tongued-and-grooved-chipboard-flooring/invt/164516/

I am paranoid about the tiles cracking after reading so many horror stories. I have seen numerous posts that suggest fixing hardiebacker onto existing floorboards, but my question is do I still need to put hardiebacker down seeing as I've replaced the floorboards? I have put in extra noggins to secure the flooring as much as possible.

I don't really want to put down an extra 6mm if possible as the floor height is perfect at this moment in time.

Any extra advice that you tiling pro's may have that may help out will be greatly appreciated.

Thanks in advance.

[Dave]

Hello and welcome.. IMO it is not good to tile direct to Chipboard.. It would have been ideal to use marine ply instead of the chipboard..

[whitebeam]

I would fix 6mm hardie on the chipboard personaly as your've allready changed the existing floor.

[kilty55]

defo overboard with 6mm cementy boards,not good to tile to chipboard

[Stewart]

Defo 6mm cement board, glued and screwed. 6mm in nothing in the grand scheme of things and chipboard is unsuitable to tile directly onto....

[aph257]

no to tile onto chipboard defo put a 6mm cement board on top then tile.

[Ryaneb85]

Wow thanks for all the replies so far, wasn't expecting a response so soon! Yeh I realised my mistake as soon as I put the chipboard down and that I should have put down ply. I haven't fixed the board down yet as it's been up for the plumber to finish off. Question is now, is it best to scrap the chipboard and put down 18mm marine ply instead or put 6mm cent board on top of the existing chipboard?

Do you think this is enough to eliminate any movement and therefore tiles cracking?

Apologies for all the questions, first time tiling a wooden floor!

[Stewart]

If you change to ply, I would still recommend the backer board....

[aph257]

Yep as Stewart says

[Perfect Tiling]

Even with marine ply down I would still put down the 6mm hardibacker...it gives a much better substrate to tile onto. Marine ply can have its problems too, as being waterproof it will not let the adhesive draw into it to give a good bond. With the hardie it is cement based, so will give a better hold to a cement based adhesive which is what you must use on a floor. I usually prime the floor, apply adhesive with a 6mm float, put down the hardie and walk over it to bed it, screw down at 250mm centres then wipe with a damp sponge as you lay adhesive for tiles. Never had a failure yet. If you want tiling practice...tile onto the chipboard...then you can do it again in a few weeks...LOL. Do it right...do it once!

[nybor62]

take out chipboard put 15mm ply 6mm backer board , your only gaining 3mm

[Ryaneb85]

Thanks for the advice so far. I think I will just put cement board on top of the existing chipboard as it doesn't sound like it will be that advantageous replacing the chipboard with ply and then cement board.

Before I move on with the tiling tomorrow, am I right in thinking there is nothing more I can do to reduce deflection/movement or anything that is going to cause the tiles to crack?

Thanks

[whitebeam]

Your've allready put extra noggins in, just make sure theres no bounce.