Building Stairs

Stair Construction

Category Construction Glossary
Calculating Stairs

The rise height of each step is measured from the top of one tread to the
next. It is not the physical height of the riser; the latter excludes the thickness
of the tread.
tread depth or length is measured from the edge of the nosing to the
vertical riser. It is sometimes called the going.
total run of the stairs is the horizontal distance from the first riser to the
last riser. It is often not simply the sum of the individual tread lengths due to
the nosing overlapping between treads.
total rise of the stairs is the height between floors (or landings) that the
flight of stairs is spanning.
slope of the stairs is the total rise divided by the total run (not the
individual riser and treads due to the nosing). It is sometimes called the rake
or pitch of the stairs. The pitch line is the imaginary line along the tip of the
nosing of the treads.
Headroom is the height above the nosing of a tread to the ceiling above it.
Walkline - For curved stairs, the inner radius of the curve may result in very
narrow treads. The "walkline" is the imaginary line some distance away from
the inner edge on which people are expected to walk. Building code will
specify the distance. Building codes will then specify the minimum tread size at
the walkline.
To avoid confusion, the number of steps in a set of stairs is always the
number of risers, not the number of treads.