Hello Louis, the sleeve set-up is by far the simplest way in which to set-up and build a spiral staircase. When you are attaching the steps/treads directly to the pole there is a lot more chance for errors in spacing, levelling, etc. and it is much more difficult to do the layout. I have built stairs both ways and the direct tread method is much more of a challenge. Using the sleeves gives you the latitude to put the parts in place and then bring everything into line without a lot of hassle and then weld it to exactly fit your needs. You would be able to put the center pole in place and carefully position it to ensure a good fit and that it is level/plumb prior to installing the treads. When you put the treads into place you could locate the bottom tread and the top tread and then very easily space all of the other treads to make everything even and symetrical. Regardless of which choice you make there is some initial layout required to ensure that your treads are the correct width/length and once they have been spaced out that you will have the correct amount of tread extending past the nosing of the tread directly above it. Good luck on your project and please post up your progress as you work on it. I and others would certainly enjoy seeing how it turns out. Good luck and best regards, Allan
Ditto what Marshall said.
