ᐅ Floor construction with insulation for the ground floor

Hello,

we have an extension on our house (built in 1950) that is about 60cm (24 inches) above ground level (accessible from outside via a small staircase). A kitchen is planned for this space. The structure is built on a brick strip foundation. Below the floor is compacted soil, on which we have laid a vapor barrier and then poured a concrete slab. Currently, the base around the room has been treated with a horizontal damp-proof course and finished with about 40cm (16 inches) of base plaster.

My question is: how should we proceed with the floor construction? The water supply pipes, drainage pipes, and heating pipes for a radiator will need to run through the floor. The initial plan was to install a Katja Sprint track (screed track) with insulation on top (with the pipes laid within this layer) or use loose-fill insulation, followed by dry screed panels and then tiles or vinyl flooring. Does this make sense, or is it a bad idea? We are uncertain about the insulation part. Is loose-fill insulation feasible, or should we opt for insulation boards?

Unfortunately, we are not professionals, and so far, we haven’t been able to find any tradespeople willing to work on this room (about 7sqm (75 sq ft)) for us.

That works either way; whether using loose fill or panels is actually irrelevant. In my opinion, panels are easier to work with.

Do we still need to install vapor barriers anywhere? And if yes, where?

No, you need a moisture barrier against the ground – that’s exactly what Katja mentioned. Alternatively, you can also simply heat-weld it.