Stairwell edge insulation strip or not

Hello,



This is the current status at the stairwell opening. I have now laid insulation and stapler board up to 10 cm against the stairwell opening. Then the formwork will be installed. The builder said that later a screed will simply be poured and then it will crack at the transition from "only screed" to screed with insulation. Is that correct or rather botched work? I have now first installed the edge insulation strip as shown in the picture. But I don’t know if the screed ring will hold then. The stairs or the railing will be fixed there.

What made you decide not to lay the insulation? I don't see any sense in that.

What kind of railing is planned? Often, screed angles are mounted on the railing, on which the insulation and screed are applied.

According to the stair builder, there should be a 10-15cm strip without insulation at the stairwell opening. This allows him to attach the staircase there.

when does he want to do that? does he want to drill through the screed into the raw subfloor afterwards? I know this as described with screed angles. that goes on the raw subfloor, then insulation, underfloor heating, screed. then he can mount his railing against the angle afterwards

I assume that he does not drill through the screed into the raw subfloor but only into the screed.

He usually doesn't hold something like that. Better ask him again. Metal or wooden railing? How should the view in the stairwell be?