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.