Confused diy'er please advise

[bobandsmiffy]

evening all,
im preparing a floor,(floorboards on joists) for tiling
and, i am so confused,,some sites say ply others say ditra matting?

the area to be tiled (with 300x300 dark slate effect tiles) is 15sq mtrs

please advise ply or matting,,?
what else would i need to do to ply and what size?
what adhesive and grout would i need,,make if poss?

sorry to ask so much but i need help from you experts
thanks for reading
hope you can help
andy

[GazTech]

http://www.tilersforums.co.uk/tile-a...tml#post120171

[bobandsmiffy]

i know gaz,
just been looking all over but have had no joy with actually getting any info on materials,,makers etc
please help

[grumpygrouter]

Ditra does not stop a timebr floor deflecting, it is a decoupling membrane for LATERAL movement of the substrate. If you floor has any boumce then it should really be over boarded with 18mm ply, screwed every 300mm or less. if you are going to use BAL adhesives (single part flexy or the rapid set version) then you should seal the back face (non tiling side) and edges with BAL Bond SBR prior to screwing down.

An alternative product is Ardex-flex 7001. This si desigened specifically for timber floors. If you use this the ply must be sealed as above but with polyurethane varnish and the tiling face must be primed with Ardex P51 primer. You will need less of the Ardex than the BAL adhesives as it is mixed to a thin consistancy which not only goes further but helps to ensure a solid bed of adhesive.