19 Building and construction materials and elements, not of metal; Statues and works of art made of materials such as stone, concrete and marble, included in the class; Structures and transportable buildings, not of metal; Doors, gates, windows and window coverings, not of metal; Precast pavers; Spackling compound; Armour-plating, not of metal; Pitch, tar, bitumen and asphalt; Stone, rock, clay and minerals; Wood and artificial wood.