ᐅ Floor construction without underfloor heating

Hello,
We will start building our passive house at the beginning of 2024. Heating will be fully provided by the ventilation system, with only electric underfloor heating in the bathrooms. I just realized that we might not need a traditional screed and could use a dry construction method instead. This could be done with a cross battens system, cellulose insulation, and then a plank floor. What I’m not entirely sure about is the transition in the hallway and bathrooms, where we have tiles. How can we achieve a smooth transition and end up with the same overall height?
The total floor construction is 16 cm (6.3 inches). Cross battens with impact sound insulation are 14 cm (5.5 inches), and the planks are 2 cm (0.8 inches). Could we use a dry screed in the tiled areas, then Fermacell boards, and tiles on top of that? Or are there other options?
I hope my question is clear, and thank you in advance.

whoracle schrieb:

Would it be possible to install a dry screed in the tiled areas, then Fermacell boards on top, and then tiles? Or are there other options?

Yes, you can install a dry screed using a cross battens system; Fermacell boards actually serve as a dry screed. There are also specific boards designed for wet rooms to prevent the gypsum from swelling too quickly if there is any leakage. It’s better to use a load-bearing infill material between the battens rather than cellulose.
Alternatively, you can omit the battens entirely and lay EPS/XPS/PIR boards directly, then install the dry screed on top.
If you’re tiling anyway, you can also use XPS construction boards with fiberglass mesh and a cement coating (such as WEDI boards or Jackoboard) in the bathroom. This eliminates the need for a dry screed, as these boards can be tiled directly.

Ok thanks. So the easiest option, if you want to tile anyway, would be these WEDI panels or Jacko construction panels. And with those, you could also build up high enough so that the tiles end up at 16cm (6.3 inches) as well?

Please still remember to properly seal the floor. Simply placing the boards on the floor (regardless of type) is not professional practice.