Additional spacers (bottom strips for foil) can be inserted under the hollow bodies for height adjustment. The 1st concrete layer must be installed at least 2 cm above the upper layer of the lower reinforcement and at least to the lower edge of the hollow body (no opening between hollow body and concrete).

If the concrete does not rise in the hollow body due to the choice of the thickness of the 1st concrete layer, the weight saving can be a maximum of 0.32 kN / m² (0.0128 m³ / m² concrete) higher.

Hollow bodies can be installed in approx. 70% of the ceiling area of a conventional point-supported hollow body ceiling. The edges of the panels and the area surrounding the recesses must be solid with an area at least as large as the panel thickness h.

For easy installation of the shear reinforcement, the concrete cover of the lower reinforcement layer should be at least 35 mm. The maximum bar diameter of the lower reinforcement layers is 16 mm. No double bars may be arranged. The minimum bar spacing is 100 mm. This value can be used for a

of the two lower reinforcement layers can be reduced to 75 mm if at the same time the bar spacing in the other direction is ≥ 125 mm.

Specifications from fire protection standards may have to be observed.