How to make a warm floor in the dome, on the wooden interfloor overlapping

How to make a warm floor in the dome, on the wooden interfloor overlapping

People often ask: “How to make a warm floor in the dome, on the wooden interfloor overlapping?” I decided to give a couple of examples for clarity:
Option 1. Water heated floors in the dome Yardom 11m, for wood, factory made.
Video tutorial  https://www.youtube.com/watch?v=WiQFanYthiM
Option 2:
But why pay more if you can do it yourself?
https://www.youtube.com/watch?v=7w4v7IM4qyc
https://www.youtube.com/watch?v=70ySURj85j0
https://www.youtube.com/watch?time_continue=41&v=..
Option 3:
Semi-dry screed. In this case, the load on the overlap increases. But the deflection of the floorboard is reduced, as a result, the floorboard can be reduced in section. Or even use not grooved, like formwork.