Non-metallic building materials, namely, bituminous coatings for roofing; bitumen; bituminous coating compounds for roofs; bituminous membranes and preservatives being granules of calcined kaolin or calcined kaolin-feldspar-quartz mixtures for roofs; silica, namely quartz; quartz sand, quartz powder, in particular for use as reflective granules for roof coverings and roof tiles, not made of metal