Adding Spiral Stairs

You can add spiral stairs to a building model.

See Also
Creating a Mass
Activating a Story

Context: Spiral stairs are like circular stairs, except instead of an inner diameter, a spiral staircase has a pole that supports the structure. Spiral staircases have treads, without risers. They are often used as focal points and when stair space is limited.

  1. Before you begin:
    1. Create a mass with two or more stories.
    2. Activate the story where you want to locate the bottom of the spiral stairs.
  2. From the Building section of the action bar, click Spiral Stairs .
  3. In the 3D area:
    1. Drag the spiral stairs to the desired location.
    2. Use the Robot at the bottom of the stairs to position the stairs and to change the orientation of the stairs.

      Note: To increase the visibility, zoom to the stairs.

    3. To adjust the spiral stairs height, drag the Height handle.

      Alternatively, enter the height in the top value box.

  4. To change the elevation for the bottom of the spiral stair, in the Spiral Stair dialog box, in Starting Story, select a story.
  5. In the Spiral Stair dialog box, from the stair option list, click Stair Diameter .
    1. In the 3D area, in the bottom value box, enter the stair diameter or drag the Stair Diameter handle.
    2. In the dialog box, in Pole Diameter, enter the diameter of the pole.
    3. In Pole Above Height, enter the distance that the pole extends beyond the spiral stairs height.
  6. In the Spiral Stair dialog box, from the stair option list, click Tread .
    1. In the dialog box, in Tread Angle, select the tread angle from the list.

      A larger tread angle results in larger treads and fewer steps per revolution. Larger tread angles also increases the headroom of the spiral stairs.

    2. In Overlap Distance, enter the distance by which consecutive treads overlap each other.

      A lower overlap distance results in fewer steps per revolution, and more usable area per tread. Lower overlap distances also reduce the headroom of the spiral stairs.

    3. In Tread Thickness, enter the tread thickness.
    4. Select the Circular Tread check box to create circular tread edges.
    5. In Top Tread Type, select the shape.
    OptionDescription
    Same Sets the shape and size of the topmost tread the same as the rest of the staircase.
    Circular Creates a circular top tread. In Top Tread Angle, select the size of the tread from the list.
    Triangle Creates a triangular top tread. In Top Tread Angle, select the size of the tread from the list.
    Rectangle Creates a rectangular top tread. In Top Tread Depth, enter the depth of the top tread.
    Square Creates a square top tread. In Top Tread Angle, select the size of the tread from the list.
  7. To change the total number of risers, that is, the number of steps, in the Spiral Stair dialog box, from the stair option list:
    1. Click Number of Risers .
    2. In the 3D area, in the bottom value box, enter the number of stairs.

      Note: A larger number of stairs reduces the headroom and distance between consecutive treads.

  8. To change the stair orientation, in the Spiral Stair dialog box, click either:
    • Clockwise .
    • Counterclockwise .
  9. Click .

The system adds the spiral staircase to the building. In the tree, the system lists the spiral stairs in Shell and Core.