I am certainly not an industry expert but my recollection is that when you lay a wood floor over cement slab you have to use a moisture barrier in the middle. I cannot believe that laying a moisture barrier is more work then all of the work that would go into a tile floor. But I can believe that it might be more costly in terms of materials. You really should research this point - once you decide on the flooring that you want, read its installation instructions- so that you are well-versed and can have a coherent discussion with the GC... I would also ask him point-blank if he has ever done this. It could be he has not and that he does not have a sub who knows how to do it well either...

You can install anything over anything you want, even tile over carpet ... but you will often be very unhappy with it. What do the installation directions for THAT BRAND say? If they say it's possible and if they give clear directions, and if the tile is in excellent condition, and if you know the floor joists are string enough for the extra load .... then yes. By the time you get the underlayment and adhesive, your floor height will be high enough that your baseboards will look strange and doors will need trimming for clearance. And the weight of the floor might exceed your joist carrying capacity. If you want to cover up old crumbling tile ... don't do it. That doesn't fix the problem and the floor will continue to deteriorate. then you have two floors to demolish instead of one.

Did you end up going with these floors, and if so, are you happy with them and do you have any pictures? We just chose these for our bedeoom, but can only find the pictures on the manufacturer’s site.

Yes they could have- we can’t know. What brand of flooring is it? What do the specifications say? What is your subfloor? What was there before? Do you know what they used?