Floor construction with insulation ground floor

Hello,

we have an extension on our house (built in 1950), which is about 60cm above the ground (accessible via a small external staircase). A kitchen is planned in this room. The room is built with a ring foundation made of bricks. The floor is soil underneath, which we have compacted, laid a vapor barrier, and then poured a concrete slab. The current status looks like this, and we have also added a horizontal barrier around the base and applied about 40cm of base plaster.


My question now is how can we continue with the floor construction? Water pipes, wastewater pipes, and heating pipes for a radiator are supposed to run in the floor. The plan was to use a Katja sprint track and insulation on top (the pipes should run in this layer) or loose-fill insulation, then drywall panels, and then tiles or vinyl flooring. Is this sensible or total nonsense? We are uncertain about the insulation part. Is loose-fill insulation possible, or should one use insulation boards here?

Unfortunately, we are not professionals, but we have not found any craftsmen willing to work on the room (approx. 7sqm) for us.

You can do it that way, whether screed or panels, it doesn’t really matter; in my opinion, panels are easier to work with.

Do we then still need to provide vapor barriers somewhere? And if yes, where?

No, you need a moisture barrier against the floor - that's what the mentioned Katja is doing. But you can also simply weld it shut.