A wall is then developed within the brackets. Then the finished treads are bolted set up. These treads might be of metal or Wooden or wood clad metal. Cantilever steps must be designed by a structural engineer, to ensure they continue to be horizontal and rigid with use with time. https://staircaseinspirations.weebly.com/blog/the-rise-of-cantilever-staircases-in-contemporary-homes