First, the old floor covering is removed down to the concrete.

Any gaps are filled with levelling compound and smoothed out.

High-performance insulation boards are laid in a staggered pattern to the greatest possible thickness. 

To ensure that any water which may seep under the floor covering (e.g. when mopping) cannot under any circumstances reach the insulation boards, the joints must be completely sealed with aluminium adhesive tape; this must also be done where the boards meet the walls.

The following constructions would be possible:

1. OSB boards, 15 mm, with cork
2. OSB boards, 15 mm (tongue and groove), with linoleum, PVC or carpet
3. Laminate flooring laid as a floating floor on 15 mm OSB boards
4. Vinyl on 15 mm OSB boards, laid as a floating floor
5. 15 mm solid wood click-lock parquet, laid as a floating floor (directly onto the boards, without OSB)
6. 4 mm click-lock linoleum flooring, laid as a floating floor (directly onto the boards, without OSB)

The greatest possible insulation thickness should be selected. However, this is limited by

1. connection issues with stairwells

2. existing room doors (which, if they are to be retained, will need to be trimmed at the bottom)

   It is therefore recommended to use high-performance insulation boards of the greatest possible thickness.