The designer is to select an appropriate load duration after careful consideration of the particular aspects of the particular purposes to which the floor under consideration is to be used. The use of short, medium and long term loading has been a traditional selection in the past and has been modelled in the NZ 3603 “Timber Structure Code” which is the only New Zealand design standard which incorporates such methodology. Out of necessity, the load history used in short and medium duration tables are simplistic, and as a consequence the designer should consider carrying out of a serviceability analysis for their particular project. Alternatively, a conservative approach is advised and if there is any doubt, long duration loads should be selected.