A wall is then constructed around the brackets. Then the completed treads are bolted in place. These treads may be of metal or wood or Wooden clad steel. Cantilever actions should be made by a structural engineer, in order that they remain horizontal and rigid with use after some time. https://socialimarketing.com/story5369095/how-cantilever-staircases-can-save-you-time-stress-and-money