After creating a sketched stair, you can set the tread thickness of monolithic stairs to 0. Monolithic stairs have their stringers, treads, and risers all made from the same material, such as concrete. 
- In the drawing area, select the stairs. 
  
 
-  On the Properties palette, click 
	 
 Edit Type. 
   
- In the Type Properties dialog, under Construction, select Monolithic Stairs. 
  
 
- Under Risers, clear the End with Riser parameter. 
  
 
- For Riser Thickness, enter 0. 
  
 
- For Tread Thickness, enter 0.