floor tiles on old tiles

No.

 

I'd say maybe. The big problem is levels. New over old is +10-15mm. If the old tiles are mega solid and the levels work out, why not? high performance adhesive and large format tiles I'm sure would be just fine - I'd do it rather than try and lay onto a very thick bed of adhesive if the levels worked that way. Any looseness/movement though and it's def a no.

 

What about any doorways,you raising kitchen floor height, your creating a trip hazard from other rooms.

 

"i spoke to topps tiles today and they say it fine to"

Well to paraphrase the late Randy Mice- Davies " They would wouldn't they"

Take the damn things up and start again.

 

The correct way to do the job...

Too many if & buts tiling on top of the exsisting tiles.

 

Mostly I'd agree, but if I was trying to raise the kitchen floor to level up to say a 20mm engineered wood floor in an adjacent room, I'd defo lay on top of sound existing tiles instead of trying to build a 10-12mm bed of adhesive to get the level. In any case taking up well fixed existing tiles and getting a nice flat surface when they have been well fastened down to a concrete floor can be a b*****d. It all depends on the levels.

And BAL flooring adhesive provides preparation information for existing glazed tiles. - They recommend modifying adhesive with addition of diluted ADMIX

 

Yes you can just treat it like a solid floor but make sure grout lines for top and bottom are offset if grout lines are ontop of each other it will be a very weak point.Obviously look at levels at the door and joining into other rooms