Staircase is a very important structural element found in mostly buildings of more than a floor. The properties of materials and designs used in constructing this structural element are very important. This study addresses the development of ultra-lightweight concrete. How ultra-lightweight concrete can effectively work in helicoidal structure. The flexural strength of this staircase was analysed on a finite element software SCAD. The designed lightweight aggregates concrete is targeted to be used in staircase of a structure having the shape of helicoid. In the concrete, chopped basalt fiber portion was added to each concrete mixture specimen reinforced as reinforcement. The basalt fiber percentages used are 0, 0.45, 0.9, 1.2 and 1.6. The developed lightweight expanded clay basalt fiber concrete showed significant increase in the flexural strength. The loads applied on this helicoidal concrete staircase in SCAD were derived from the laboratory experiments conducted on the concrete specimens on the 28 days curing period. This combination of values exceeds, to the researchers' knowledge, the performance of all other lightweight building materials. Furthermore, the developed lightweight concrete possesses excellent durability properties. © 2021 Trans Tech Publications Ltd, Switzerland.