spiral staircases are a type of round stair or curved stairs that consists of individual steps, or treads, that is connected to a center column. The treads rotate around this central point as you go up or down the stair, creating a spiral design. Al Safeenah making a customized spiral staircase as per customer imaginary models and developing the design. spiral staircases are a type of round stair or curved stairs that consists of individual steps, or treads, that is connected to a center column. The treads rotate around this central point as you go up or down the stair, creating a spiral design.