A wall is then developed across the brackets. Then the concluded treads are bolted in position. These treads could be of steel or wood or Wooden clad steel. Cantilever steps must be developed by a structural engineer, making sure that they remain horizontal and rigid with use after a while. https://staircaseinspirations.weebly.com/blog/the-rise-of-cantilever-staircases-in-contemporary-homes