Issue Description
When using the Stair tool, we might need more flexibility to create what we are looking for. Here you can read how to easily create a stair with an open tread.
Solution
In the Stair Settings Dialog go to Structure, which is available in a list on the left of the window. Here you can change the structure type of your stair. For this example, we will choose Stringers Only for both Flight and Landing Structure, and remove the Stringers on the left.
You will notice that when you change the Flight or Landing Structure, the two subsections expanded under 'Structure' (on the left of the Settings Dialog') will be updated as well.
Go to Structure > Flight - Stringers. Here you will find different settings such as Structure Shape which can be Straight or Stepped, as well as connections, materials and profiles. Similar options are available for the Landing.
To create the open Tread, go to Finish. We do not need risers in the model, so we will choose the option Tread.
Go to Finish > Tread, where you can modify the Tread profile, materials, and dimensions.
Click Ok and we are all done!