Span Tables for Flat Roof Joists (to BS 5268-7.2)

Imposed loads of 0.75 kN/m² for maintenance and snow load are applicable where there is no permanent access (no fixed ladder or staircase) and most areas where the altitude does not exceed 100 metres (refer to BS 6399-3)

Imposed loads of 1 kN/m² for maintenance and snow load are applicable where there is no permanent access (no fixed ladder or staircase) and most areas where the altitude exceeds 100 metres but does not exceed 200 metres, but excluding parts of Scotland, Pennines, North East England (refer to BS 6399-3)

Imposed loads of 1.5 kN/m² are applicable where there is permanent access to the flat roof. For example, a fixed ladder or staircase (refer to BS 6399-3)