Any Tilers on?

The staff at B&QA should be able to help ya

very funny MAKE MY HAY

Is the slope on your kitchen floor running up hill or down hill?

Years ago we used to use stuff called self leveller on cracked uneven floors, if that's still about it might do the trick ;)

avoid B&Q like the plague. It is pot luck which staff and knowledge they have, but more importantly B&Q do not sell good quality adhesives etc.

I'm half decent at tiling, and the brother in law is a professional contractor so I get good advice. It does sound like a job that requires decent application of levelling compound.

I'd get advice from a tiling contract supplier and go with that, but why not take the tiles up?

often tiles are laid upto a kitchen and finish just under a plint board which is easily removed. even it wall to wall, you can remove them to just beyond the plinth. at very worst, cut from half a tile out with an angle grinder and remove them that way, and level upto the old, (half), tile. Removing tiles is quite easy too. once the fist one is out then a lump hammer and a bolster chisel will probably take an hour.

*f kin