I've actually come across OP, decent guy imo. Where, I wonder, did we all learn that floating floors shouldn't be tiled on?, was it something that we genetically inherited "don't tile floating floors" gene, or was it something we were taught, or maybe somehow along the line had the absolute audacity to ask? I can see the humour in some replies and had a giggle, but some posters need to get their heads outta their butts...unless of course they have the "know it all" gene.
Well , seeing as you're asking.
I went to price a job in Bristol some 15-20 years ago , first floating floor I'd come across. It had lino down all through the hallway and into the kitchen diner and what first struck me was I could see all the ridges ( joins ) in the chipboard coming through the lino. Now having seen a chipboard job with cracks all along tiles where the chipboard joins were when I first started tiling - we tiling a pool there and someone else had tiled this floor before we got there - I was already wary of chipboard.
So , I got a mate of mine was a rep at the time to come with me and have a look . He was hmming and harring about ply then fast flex , then we got to the joints in the chipboard being fulcrums over which tiles could crack and I was already walking out of the door.
But what finally nailed it was when he stood in the door way and sort of jumped up and down , the floor was moving by probably 5mm-10mm. At which point I turned to customer and politely recommended more soft flooring.
So no , I didn't inherit it and luckily for me I didn't learn the hard way. I learnt by doing my research and checking it out then making the decision to walk away.
So to give the op his due he is doing the correct thing by doing his research , but he also needs to ignore the dafty posts on here - which are part and parcel of a forum like this imho - and sort the wheat from the chaff as it were.
Diggy