What Is Staircase?
A staircase is a structure with number of steps that lead from one floor to another. It is provided to allow the means of ascending and descending between the various floors of the building.
The room or enclosure of the building, in which the staircase is located, is known as a staircase. The opening or space occupied by the stairs is known as the staircase.
What is Dog Legged Staircase?
This types of staircase are named as Dogg-legged Staircase due to its sectional elevation resemblance to a dog’s leg.
Dog-legged staircase comes under half turn stairs, where flights of stairs takes 180 degree turn, it consists of two flights run in opposite direction with a landing space in between as mid landing. And these stairs provides access to different floors of the building.
These type of stairs are designed or used where available space is equal to the twice the width of the stairs. Usually used in residential buildings and public buildings. And dog leg stair are most economical staircase.
Components of dog legged staircase
● Landings- where two flights inter-connects and change of flight direction takes place.
● Step- Each step consist of a tread and a riser.
● Riser- Riser is the vertical section between each step of the stair.
● Thread- it is the flat part on which you step on.
● Handrail- These are provided for support purpose.
● Newel- Provided at starting and ending of a flight.
● Nosing- Extended part of thread.
Advantages of Dog-Legged Staircase
● Efficient use of space: Covers less area when compared to straight stairs Suitable for more compact stair arrangement.
● Privacy: Dog legged helps to maintain your privacy’s they divide the floors with mid landing which covers direct sight of top floor or ground floor vice versa.
Disadvantages of Dog-Legged Staircase
● Bit Difficult to build when compared to other staircase.
● Planning is need to place Handrails on these stairs
Requirements for Good Stairs
The below given requirements must be met, in order to build strong and durable staircase.
Location: Proper staircase location helps In easy access to all the room.
Length of flight: Flight should have minimum 3 risers and maximum 16 risers.
Pitch of stairs: Stairs are inclined from 15 to 55 degrees, however, the recommended stair angle is in between 25 to 40 degrees. Long stride should be flattened using landings.
Landing: The width of the landing must not be less than the width of the flight of stairs.
Step Proportions: The rise/rise of each stage on a flight and on flights and landings between floors must be the same. Any variations can ruin the pace. The climb/climb is provided to ensure comfortable access.
Example: Dog-Legged Staircase Design
Designing a Dog-legged staircase for a residential building, where the space provided is 2.5mx 4.5m and the floor to floor height is 3.3m
Solution:
Generally, for residential buildings, we adopt Rise and the pitch of each step is 150 mm and 225 mm.
Stairway dimensions
1 = 2.5m x 4.5m
Floor height = 3.3m
Total number of flights = 2
So, flight height = 3.3 / 2 = 1.65m
Elevation = 150mm, Floor = 225mm
No. of risers = 1650/150 = 11
Therefore, number of steps = 11-1 = 10
Adopting stair width = 1.2
For 10 steps, the required length = 10 x0.0225 = 2.25m
Landing width = (4.5-2.25)/2 = 1.125m