The subfloor

The flooring can be laid directly on aligned joists that are placed 40 cm apart.
- Check alignment with a mason's line or a screed board.
- If there is a floor made of particle board directly over the joists, put a wedge under the flooring, if required, and nail it down.

If you are installing nailed down flooring, screw or nail the backing strips onto the joists, adding wedges between the backing strips and the joists if necessary. The backing strips are to be placed perpendicular to the joists.

To install flooring on concrete slabs, begin by placing the backing strips.