a) Hardcore is compacted onto the reduced ground level after the first 150 to 250mm of the topsoil is removed. Topsoil is soft and compressible, and contains growing matter, therefore it must be discarded. Mention four principal components of a solid concrete ground floor. b) The main functions of floors are to provide a flat surface, to support load, sound, heat and fire insulator, also act as a divider or upper part as a ceiling to the occupants. Critically examine a floor/slab and state precisely what might be the causes of water lodging in corridors due to driving rain. C) There are several factors considered appropriate to floor or slab construction from, structural timber, in situ plain and reinforced concrete and precast self-centering concrete floors. As an Engineer, produce design considerations and functions of the floor(slab) must fulfill.