• 1
    Design sketch

    This stairs use to connect first to second floor, only one way, so I take around the building and make a sketch for the first design.

    Of course, I need to design in 3d view, I want to see every angle of stairs. For this, I use SketchUp on web.

  • 2
    Design details

    Let's make it more clearly. All details have designed. With this drawing, I can calculate how much materials I need.

  • 3

    First, I've made main bearing structure. Most of herringbone stairs use standing pillar to support stairs, for me, it's not pretty at all, I want the steps to fit into the main load-bearing structure, less is more. 
    I've weld main structure first, then use truckle to pull it up in position. This is most heavily job that i have to do, I tight the structure with rope and rotate the truckle. Finally here:

    Keep finish main load-bearing structure left. Then welding each step on ground then bring it up like image below, step by step.