The (2nd floor flat) kitchen floor is 18mm ply screwed directly to the
joists. There are no floorboards underneath. It seems to me to be
fairly sturdy and level. But there are a few uneven joints (2 or 3 mm
height differences) between boards and there is a lot of lino adhesive
residue left behind.

I want to cover it with slate tiles. I intend to stick them with BAL
single-part flexible adhesive and grout with BAL superflex wide joint
grout. I will prime the plywood with diluted PVA.

I'm worried about three things:

Is 18mm alone ply stable enough to tile onto?

What should I use to flatten the uneven joints? Or will the adhesive
fill the irregularities OK?

Will the remains of the lino adhesive cause problems with the tile
adhesive sticking?

Thanks!

Duncan

Duncan wrote:
The (2nd floor flat) kitchen floor is 18mm ply screwed directly to the
joists. There are no floorboards underneath. It seems to me to be
fairly sturdy and level. But there are a few uneven joints (2 or 3 mm
height differences) between boards and there is a lot of lino adhesive
residue left behind.

I want to cover it with slate tiles. I intend to stick them with BAL
single-part flexible adhesive and grout with BAL superflex wide joint
grout. I will prime the plywood with diluted PVA.

I'm worried about three things:

Is 18mm alone ply stable enough to tile onto?

Yes.


What should I use to flatten the uneven joints? Or will the adhesive
fill the irregularities OK?

Adhesive will..use thick bed though. - at lest 10mm

Will the remains of the lino adhesive cause problems with the tile
adhesive sticking?

Might do.

Could be worth sanding it all

Thanks!

Duncan