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Explanation of Parts & Terminology

This glossary of staircase related terminology is by no means
exhaustive but does detail the most common and basic terms
used in staircase construction and balustrade installation.

 – the vertical member, plain or decorative,
that acts as the infill between the handrail and baserail (or
tread if used on a cut string staircase).

Balustrade – the collective name for the complete assembly
of handrails, baserails, newels, spindles and caps.

Bullnose Step – usually at the bottom of the stairs with one or
both ends of the step having a rounded corner

Curtail Step – a wider decorative shaped step at the bottom of the

Closed String – a string with the face housed/trenched to
accommodate treads and risers so their profile cannot be seen.

Cut or Open String – a string with the upper edge cut away
to the shape of the treads and risers so that their profile can be
seen from the side.

Wall String the string fixed or adjacent to a wall.

Out String-a string not fixed or adjacent to a wall.

Continuous Handrail – using lengths of handrail
connected to handrail fittings and ramps, the handrail flows over
the tops of newel turnings creating a continuous run of handrail.

 – the going of a flight of stairs is the horizontal distance
between the face of the first and last risers. The individual
going of a step is measured from face of riser to face of riser.

 – vertical post in balustrade which accommodates the strings, handrails and treads/risers
of stairs.

Nosing – the edge of the tread projecting beyond the face of
the riser and the face of the string in the case of a cut string.

Top Nosing – forms joint between final riser of flight and upper floor or landing.

 – the angle of the stairs. NB max for private stairs is 42 deg.

Pitch Line
 – the notional line connecting the nosings of all
treads in a flight of stairs.

 – the board that forms the vertical face of the step.

Stairway/Stairwell – the space/void provided for the stairs.

Step – the tread and riser combined.

String Margin
 – the distance between the top of the string
and the pitch line measured at 90° to the pitch line.

– horizontal part of a step.

Scroll – a handrail detail like a Monkey’s Tail.

Wall String 
– the string of a staircase fixed to a wall.

Winders – are radiating steps narrower at one end that are
used to change the direction of a stairs.