How to measure the slope of a staircase
This construction video is created by Jim Fowler, PhD, The Ohio State University, and it provides the detailed process for measuring the slope of a staircase. Here the staircase contains small steps and large steps. For small step height is taken as 6.25 inches and width is taken as 12 inches. For large step height is taken as 18.75 inches and width is 36 inches.
So, slope for the small steps = 6.25/12 and slope for the large steps = 18.75/36.
These two slope are equivalent as we can reduce its fraction by dividing numerator with 3 and denominator with 3.
The slope can be applied for ascertaining steepest flight of stairs.
There are horizontal and vertical surfaces in the flight of a staircase. The vertical surface is known as riser and the horizontal surface is known tread. The combination of these two create the step is formed by combining these two together.
The vertical dimension that is enclosed in one step is known as the rise. The horizontal dimension enclosed in one step is known as the going.
The slope or pitch of the stairs refers to the proportion among the rise and the going. It is also known as the rake of the stairs. The pitch line stands for the imaginary line along the tip of the nosing of the treads.
A staircase rises up at an angle from the horizontal. So, stair pitch means the angle the pitch line creates with the horizontal, calculated in degrees. The value of the slope, as a ratio, becomes the tangent of the pitch angle. Upto a maximum of 42 degree is recommended for pitch.
While rising from starting level to the last level, the horizontal distance covered by the staircase is described as the total going or total run.
If handrails exist in staircase, there should be minimum width of 900 mm among handrails for smooth usage.
To obtain more detail information, watch the following construction video tutorial.