Terminology used in stair construction

A stair is a set of steps (a series of risers and treads) that connects floors at different levels, giving access from one storey to another, usually with landings and a balustrade.

Terminology used in stair construction

• Tread: the horizontal top surface of a step on which the foot is placed (usually 250-300 mm).
• Riser: the vertical face between two consecutive treads (usually 150-175 mm).
• Going: the horizontal distance between the faces of two consecutive risers; the total going is the horizontal length of the flight.
• Rise: the vertical distance between two consecutive treads, or the total vertical height of a flight.
• Nosing: the projecting edge of the tread beyond the riser (about 25 mm), usually rounded.
• Flight: an unbroken series of steps between two landings.
• Landing: a level platform between flights or at the start and end of a stair; a half-space landing turns the stair through 180 degrees, a quarter-space landing through 90 degrees.
• Winder: a tapered (radiating) step used to change direction.
• Soffit: the underside of a flight or landing.
• Waist: the thickness of the inclined RCC slab, measured perpendicular to the slope.
• Baluster: a vertical member (post) between the stair and the handrail.
• Balustrade: the complete protective barrier of balusters, handrail and newel posts.
• Handrail: the rail on top of the balusters, held by the hand (about 0.9 m high).
• Newel post: the main post at the start, end or turn of a flight which supports the handrail.
• Stringer: the inclined side beam that supports the steps.
• Headroom: the clear vertical distance from the pitch line (line joining the nosings) to the soffit above (minimum about 2.0-2.2 m).
• Pitch (slope): the angle between the pitch line and the horizontal, usually 25-40 degrees.
• Stairwell: the space (room or opening) in which the stair is built.
• Scotia: a moulding under the nosing.

     newel post            handrail
        ||==============================
        ||      |       |       |        <- balusters
        ||      |       |    ___|_____   <- tread
        ||      |    ___|___|  <- riser
        ||   ___|___|  <- nosing (edge of tread)
        ||__|  going
  ______||
          \  pitch line joins the nosings
           \__________________________  soffit (underside of waist slab)