Building materials (as finished products) made of concrete, gypsum, clay, potters' clay, stone, marble, wood, plastics and synthetic materials for building, construction, road construction purposes, included in this class; non-metallic buildings, non-metallic building materials, poles not of metal for power lines, barriers not of metal; natural and synthetic coatings in the form of panels and sheets, being building materials; bitumen cardboard coatings for roofing; bitumen coating for roofing; doors and windows of wood and synthetic materials