What is a Staircase in Architecture? What are the Elements and Details That Make Up the Staircase?
What is a Staircase?
They are vertical circulation devices with a certain slope that provide the connection between different elevations and are graded at regular intervals.
The elements that make up the stairs are; They can be listed as steps, risers, stair handles, landings, stair buckets, railings, head heights, staircases and exit lines.
1. STEP
It is the level of the ladder that is stepped on with each step. They can be trapezoidal or rectangular in shape. The step width from step tip to step tip is called ‘b’ step width. In staircases with rectangular steps, the step width is the same at each stage, but in trapezoidal steps, it changes along the step.
It is bmin on the narrow side, bmax on the wide side, and b in the middle. Step width should be minimum 25 cm and maximum 33 cm. The narrowest part of the step may be 11 or higher.
The number of steps is expressed as ‘m’ and is found with the formula m=n-(1+As). (n=number of docks and As=number of intermediate landings)
2. STEP HEIGHT
The vertical front edge of the step is called the riser, and the height between the top faces of two consecutive steps is called the riser height.
This height is preferred in different sizes depending on the function of the ladder. For example; garden, courtyard etc. 13-15 cm is preferred in outdoor areas, 16 cm in meeting halls such as cinemas and theaters, 17-18 cm in residences, 17 cm in public buildings, and 20-21 cm in roofs, basements, service and fire escapes.
The riser height should be the same everywhere on the ladder and step. There is a 2r+b=63 relationship between riser height and step width.
Various profiles can be given to the docks for both comfort and aesthetic purposes. In the staircase drawing, the profile end is shown as a solid line and the riser level is shown as a dashed line.
3. LADDER HANDLE
The series of steps that continue uninterruptedly between the flat parts called landings on the stairs is called ‘stair arm’.
If possible, and especially in crowded places, there should be at least two steps on the staircase arm so that the difference in elevation can be detected.
Stairs according to the shape of the staircase branch in the plan; They are divided into three groups: rectangular steps, trapezoidal steps and mixed steps.
Ladder arm length is expressed with ‘l’.
Stair arm length = Number of steps (m) x Step width (b)
Stair arm width=Step length (e.g. 120 cm)
4. STAIRCASE LANDİNG
The flat areas where the stair branches start and end are called landings. Landings provide comfort when ascending and descending, they enable straight-arm stairs to change direction and to enter floors.
The landings where you enter the floors are called ‘floor landings’ and the others are called ‘intermediate landings’. A landing with a maximum height of 2 meters is useful. It is best to arrange them in the middle of the floor. The elevation difference between two landings should not exceed 3 meters.
The width of the landing perpendicular to the exit line is called ‘landing width’. It should be at least 100 cm and never less than the width of the stair arm.
The length parallel to the landing exit line is called ‘landing length‘.
5. LADDER BUCKET
The space between the staircase arm and landings is called the ‘staircase’. The staircase ground level is the elevation where the stair treads begin.
They are made with a minimum width of 10 cm. They can be kept wider for natural lighting from above or planned as elevator shafts.
6. EXIT LINE
Assuming that people hold the railings while using the stairs, they use a certain part of the stairs when ascending and descending. This line, which passes through the middle of this region and is assumed to indicate the exit direction, is called the exit line.
It starts at the landing of one floor and ends at the landing of the next floor. Starting from the first dock, the points where each dock intersects the exit line are numbered and the required number of docks is determined. These numbers should appear on the dock according to the exit direction. Numbering starts with the output line and ends with the output line.
7. STAIRWAY HOUSE
The place where the staircase arms and landings are located is called the staircase house. It is surrounded by elements such as doors, windows and walls. It is important to determine the area covered.
8. RAILING
On stairs with more than five steps, the free edges should be protected by handrails. They provide descent and ascent safety. The height of the railing should be taken as 85-90 cm vertically from the imaginary line connecting the ends of the steps.
9. HEAD HEIGHT
The net vertical length between the stair arms located on top of each other is called head height.
The minimum length is 220 cm for stairs making an angle of 30 degrees with the horizontal, and the minimum length is 240 cm for stairs making an angle of 45 degrees.
