Backbutter Tiles on Ply Floor?

[rustylt2]

I have a 6m x 2m kitchen floor to tile with 300 x 300 ceramic tiles. The customer has removed the old tiles and quite a bit of the old adhesive has remained on the floor. It is a fairly new house and the floor is made of ply sheets about 18 or 21mm. Rather that spend ages removing all the old adhesive the customer wants me to ply over the top with 12mm ply and tile onto that. All the old adhesive is low level with no real high spots so would it be ok to go ahead and lay the new ply floor, well screwed down every 150mm?

I will use rapid set flexi adhesive but do I need to backbutter the back of the tiles to solid bed them?

Thanks.

[Fekin]

Why not just sand down the adhesive level, prime then tile away if the floors still nice and solid.

[CJ]

No don't overply, it only takes a MM high spot and you could be in trouble.

Latex self level the area first. Or just bite the bullet and scrape away

[Dave]

Try Mapei fibre plan leveller and then tile using a solid bed trowel.......