ESZ Type Z stair bearings are supplied and installed for flights of stairs, precast reinforced concrete stairs and landings. The requirements for increased sound insulation in accordance with supplementary sheet 2, DIN 4109, must be fulfilled and verified by an approval in executed construction. Computational proof of the usability of the bearings must be provided. The general building authority approval of the German Institute for Building Technology, as well as a fire protection report are required and must be submitted to the construction management.