Height for underfloor heating

Hello,

we would like to extend our upper floor - currently there is only the concrete ceiling. Unfortunately, the windows were installed a bit low (bottom edge just 90 cm). Therefore, we wanted to get as low as possible with screed, underfloor heating, etc. Hence my question, what is the minimum height one would have to plan for?

Hello,

unfortunately, I cannot tell you the minimum height you have to calculate.

Our floor structure (screed with underfloor heating) has a height of 18 cm without flooring.

However, I have also read here in the forum about significantly lower screed thickness with integrated underfloor heating.

Regards,

Dirk

for us it is 17 cm....

Well, it can be much flatter.
One option is to use a dry screed system (underfloor heating in a system panel made of 25 mm EPS plus 2 cm dry screed), that would be a 45 mm build-up.
Then there are ultra-thin renovation build-ups with metal honeycomb panels where the pipes lie; the whole thing is poured with leveling compound and then has about 1 cm (!!) build-up height.

We ourselves have a build-up of 14 cm but we also had to chisel out the screed for that. Then 8 cm insulation alone, 15 mm OSB board, and on top of that the aforementioned 45 mm dry screed system. However, on the upper floor you don’t need additional insulation, so it will be 45 mm there. The 1 cm would have been nice too, but certainly quite a bit more expensive.

We have 14 and 18 cm (OG / EG) each with about 8 cm of cement screed.

How did you manage to get insulation and a tack board in the upper floor with 8 cm screed? Or were there no cables on the floor at all (which I can hardly imagine)?