Abstract: Formwork creates a grid for receiving a filler material which defines a floor or floor base with a water drainage outlet. The formwork comprises a plurality of first wall members (4, 12) extending from an outlet zone (6) or channel (16). A plurality of second wall members (10, 14) extend between the first wall members to define the grid, with cells formed between the first and second members. Each first wall member (4, 12) has a progressively increasing height to define a downward slope for directing water towards the outlet zone (6) or channel (16), and the height of the second wall members (10, 14) will match that of the first wall members at junctions therebetween.