Architecture: Staircase Components

Stair Components

• A step is a portion of a stair that permits ascent or descent, composed of a tread and a riser.
• A stair is composed of a set of steps.

Tread

• The tread is the horizontal member of a stair.
• The tread of public buildings must be wide enough to provide safe footing.

Going

• Going is the horizontal distance between the nosings or front edges of two consecutive steps.
• The going of public buildings is usually 30cm, providing safe footing.

Riser and Rise

• The riser is the vertical member of a stair.
• The rise is the vertical distance between the upper surface of two consecutive steps.
• The rise of public buildings is about 15cm, while a higher value can be used for private buildings.

Technical Terminologies

Nosing

• The nosing is the projecting part of the tread beyond the face of the riser.
• The nosing is usually rounded off from the architectural point of view.

Flight, Landing, and Baluster

• A flight is a continuous set of steps between floors and/or landing.
• A landing is a platform between two flights.
• A baluster is the vertical member that supports the hand rail.

Balustrade and Hand Rail

• The combined framework of hand rail and baluster is known as a balustrade.
• The hand rail is a rounded or molded member of wood or metal fixed on top of balusters.

String and Head Room

• A string or stringer is the structural member that supports the steps and acts as inclined beams.
• The head room is the minimum clear vertical distance between the tread and overhead structure.

Soffit

• The soffit is the underside of the stair.