Tiling onto wooden bathroom floor

[Shoggers]

Hi all - I'm new here.

Been reading the forum all morning picking up tips for tiling my bathroom.

I previously tiled my other bathroom walls, floor to ceiling in travertine and had no major problems, however I've never tiled a floor before.

My floor is an upstairs bathroom floor in a fairly old house. I have ripped up all the old floorboards and replaced with new 18mm thick chipboard. I have screwed this down at close intervals and its nice and flat and pretty solid.

My question is - do i need to board over the top of this with ply?

I am going to be laying 40x40cm 10mm thick slate tiles.
The bathroom is a strange shape - 1.2m wide x 4.5m long (3 tiles wide).

Any other suggestions that might make my life easier would also be appreciated.

Cheers

Ian.

[garretridge]

i would use 6mm hardibacker boards with flexi adhesive and screwed every 200mm if you use ply you need minimum 15mm exterior ply which will create a problem with height and is not as good a surface to tile on and make sure you use a good flexi adhesive and grout mapei would be my choice!

[Shoggers]

6mm hardibacker ordered - I will get that secured down tonight before tiles come tomorrow.

Is all mapei adhesive the same? - I have ordered mapei adhesive with the tiles - but when you say a "flexi-adhesive" does this relate to a specific mapei product?

[EFC Mike]

Yes it's a specific product. 'Flexible adhesive' is required were structural movement is prevalent. i.e. wooden floor, differing substrates etc.
I would suggest Dunlop large format flexi, excellent product.