floor tiling between two different floor levels

[Joeylegend]

My dining room and kitchen has been knocked into one large kitchen and I intend to floor tile across the new entire floor space now exposed.

what I have discovered is that the old dining room floor was slightly higher than the old kitchen floor, this means when I start tiling from one side of the new kitchen floor space , when I get to the middle there will be a slight drop(or rise depending on which side i start) which will affect the tiles level.

any ideas how to get round this?

 

[Richard C]

How much is slightly higher?

 

[tictic]

also what subtrates have you got?

 

[Joeylegend]

the drop would be a tile thinkness, 7-10mm,
both floors are wooden

 

[Richard C]

both floors are wooden

What sort of wooden, floorboards, ply or crapboard?

 

[Joeylegend]

large sheets of plywood for floorboards and then I screwed down sheets of plywood over the top of that, I hoped that screwing down a sheet over the drop (4ft before the drop and 4th after the drop) would remove some of the dip but it is still present , you can feel it under your feet.

 

[Richard C]

You will never get rid of such a large height difference by screwing ply over it, you will always notice it & the floor will flex, causing tile failure. Best way to do it would be to lift the over-boarding (what thickness is it?) lift the floor in the low area & either replace with thicker ply to make up the difference or fit packing strips to the joists & relay; or a combination of both. In a heavy traffic use kitchen/dining area, a suspended floor should also use 25mm WBP ply, anything less & the tiling could fail; the ply should also be WBP, not conventional ply boarding. You may also need a decoupling membrane between the two floors or it could crack where they meet; depends how it's constructed.