WPC decking on steel structure - substructure unclear

Yes, you can then see the edge of the steel frame from above.
Extrabreite Diele was also my initial thought - but 24cm wide, that won’t work :/
Solid for sure

So, the correct approach would have been to have a small crossbeam made directly by the balcony builder. In the area of the floor-to-ceiling window, simply install a "normal" exterior window sill below as a second water-carrying level (mandatory!). Then, with some distance above it, the crossbeam, on which the flooring is laid continuously up to just before the door (not directly at it, as every step on the threshold would cause movement and destroy the sealing at this point). Now open the door. Have the balcony builder measure, manufacture, and install the crossbeam. Install the exterior window sill beforehand. Then install or have installed the upper floor covering of the balcony yourself.

Thank you, but it is pointless to argue with what ifs afterwards. The steel frame is simply there and I cannot continue the flooring because it would then be too high (1. For the roller shutters of the floor-to-ceiling windows and 2. for the staircase on the other side).

Read carefully and understand! No one said that the floor covering should run through. Adjust the height of the traverse so that it fits under the door but above the windowsill. Naturally subtract the height of the floor covering upwards. Then carry out or have it made and installed as described above. The balcony manufacturer or the steelworker/professional on site will know how to implement something like this. Why do you insist on bringing some fiddling there that you won't enjoy for long and which leads to various expensive problems? Just do it once - but properly ;)

OK actually read that running through thing wrong :) :cool:

However, this solution is not feasible for the door in [Bild 3], as there is no space below for crossbeams and substructures.