Abstract: A sub-roof for roofs with roofing boards consisting of a plurality rectangular insulating boards (1) overlapping each other in direction of the slope of the roof. Each insulating board has a parallel plane central section (3), integral with a wedge-shaped board section (2) on the ridge side and a wedge-shaped board section (4) on the eaves side, the thickness of which increases towards the middle of the board. The thickness of the board sections (2 and 4) on the ridge side and on the eaves side at their edge towards the central board section (3) is at least equal to the thickness of said central board portion (3) and, when thicker boards are used, reaches said thickness after going through a step (11 and 12). The insulating boards (1) are placed so that they constitute an offset double or multiple covering.

Abstract: A roofing plate for the planting on greenery on a roof, having an approximately rectangular surface as seen from above. The roofing plate comprises a wedge-shaped upper section tapering in thickness towards the ridge, a central section of uniform thickness and of a lower section with an open channel on top. The combined length of the central section and the lower section (measured in the direction of the ridge to the eaves) is greater than the length of the upper section, so that a scale-like double or multiple roof covering can be installed. Several rows (25, 26) are installed one above the other, whereby a plurality of open channels are formed, and are located one above the other, are filled with a nutritive medium (35) for the planting of greenergy (36). Shell sections (32) are preferably inserted into the channels and hook into each other by means of beads and creases (33) so as to form a strong, sealed connection.