Lamella stone wool boards for the insulation of cellar ceilings and ceilings over garages and passageways. Lamellar wools have an ordered arrangement of fibres that are perpendicular to the surface of the board, so they have more than seven times the tensile strength. This is an improvement on classic mineral wool slabs, where the fibre arrangement is disrupted (tangled). The boards additionally have bevelled edges and are primed on one side. For the installation of the panels, adhesive mortar is sufficient in most cases, without the need for additional mechanical fasteners. The panels are glued in so-called passing and the adhesive is spread with a notched trowel.