ᐅ Sealing and Foam-Insulating the Attic Stair Opening

Hello everyone,

We are currently building a KFW40 single-family house. Recently, a branded attic ladder was installed.

We have a cold roof, so the vapor barrier is located on the upper floor with the following layer structure from bottom to top:
- Gypsum board
- Counter battens
- Vapor barrier
- 280 WLG 035 insulation between the rafters
- Cold attic space

The ladder already includes an installed "insulation pad" to ensure an airtight installation. Accordingly, the vapor barrier is not glued or otherwise attached to the ladder frame.
The installation was carried out as follows:

We are now wondering if the gap/cutout should still be sealed with foam or something similar. According to the site manager, only the trim will be installed here, and that’s it. However, warm air could continuously rise between the gypsum board and the vapor barrier. I already assume that this shouldn’t be a technical problem, but wouldn’t it still be advisable to seal it, for example with PU foam, and then cover it with the trim?

Thank you very much and best regards