Floor run length

Floor run length

The horizontal distance from the first step to the end of the staircase under the ceiling. Determines whether the flight will fit.

01 /The floor run — what it is

The floor run (the length of the flight's projection) is the horizontal distance from the first (starting) step to the farthest point of the staircase under the second-storey ceiling. This parameter directly determines whether a comfortable design will fit in the allotted space.

02 /How the floor run relates to the angle

Knowing the floor-to-floor height and the desired angle, you can easily determine the required floor length:

  • For a gentle, comfortable staircase (30°–35°): the floor run is about 1.5–1.7 times the floor-to-floor height.
  • For an optimal staircase (36°–40°): the floor run is about 1.2–1.4 times the floor-to-floor height.
  • For a steep staircase (41°–45°): the floor run is about 1.0–1.1 times the floor-to-floor height.

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Stringer length

The full length of the inclined load-bearing beam (stringer or string) that the steps rest on. The hypotenuse of the "height–run" triangle.

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The minimum vertical distance from the step edge to the ceiling or the flight above. The norm is at least 200 cm.

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The main rule of stair ergonomics: 2 step heights + depth = stride length (60–64 cm).