The load-bearing structure of an industrial stairway is subjected to widely fluctuating traffic loads. This is taken into account in EN ISO 14122. One person using the stairway without carrying a load corresponds to at least 1.5 KN/m². One person carrying a load or several people using the stairway corresponds to 5 KN/m².
The steps themselves are evaluated separately in terms of traffic loads. Each step with a width of < 1,200 mm must be able to accommodate a minimum load of 1.5 kN on an area of 100×100 mm, as measured at the center of the nosing. In the case of width of ≥ 1,200 mm, the step must accommodate the same load of 1.5 kN at several points simultaneously. Measurements are taken at the center of the nosing and at the most unfavorable points positioned 600 mm apart over the center.
The following applies to stairways and steps: The load-bearing structure and the steps must not exhibit deflection of more than 1/300 of their span and/or a maximum of 6.0 mm during load tests.