A wall is then built around the brackets. Then the finished treads are bolted in position. These treads might be of steel or Wooden or wood clad steel. Cantilever methods need to be created by a structural engineer, so that they remain horizontal and rigid with use over time. In https://staircaseinspirations.weebly.com/blog/the-rise-of-cantilever-staircases-in-contemporary-homes