tile on a floating solid TG floor

richiedc

I have a bit of a conundrum.

I have a room we are knocking through to another. The subfloor is the first room is 20mm higher than the subfloor in the second room.

The second room has 20mm floating real wood TG floor, sat floating on what looks like batton sunk into concrete. There is wet underfloor heating below.

Could we tile on top of the wood?

Builder suggested screwing down the floor, then on top adding backer board / ditra. Im super nervous about this.

Wonder if there any other options for me? I need that floor to be 20mm higher if I remove the wood, and also I want the UFH to be effective.

thanks

Rich