Spacing
The spacing of the floor joists depends on the spanning capacity of flooring being supported.
The maximum allowable spacing of joists supporting tongue and groove strip and sheet flooring relates to the species of wood, grade and thickness.
An example of this would be: South-eastern Australian hardwood, AS 2796, standard grade, 19 mm thickness, maximum spacing of joists 620/680 mm, butt joists, 470/520 mm end matched.