As we suspected. Ecofilm is not designed for tile. It should only be used for wood/laminate. It does not like moisture (i.e. adhesive or bathroom environments). The tech guy at Flexel has never heard of anyone using ecofilm for tile because they have other products for tiled rooms.
Of course if it was used and it went wrong, then there would be no guarantee.
So that's it, I've had to walk from another job!
Strangely enough I quoted for tiling a porch for the same lady customer a couple of months back. It was quarry tiles that I said needed coming up or an uncoupling membrane laid first before it's tiled. Anyway she did not take my advice. She employed a decorator that said he could tile. She was not happy with his work, nor was she too pleased that he broke several tiles that cost her half a day in buying replacements. Needless to say he went straight over the quarry tiles with different grout line thickness's and only managed to tile 15mm from the skirting.