Everything about the Dog-Legged Staircase

The building's numerous floors are accessible through staircases. The stair is made up of a flight of steps with landings at regular intervals. Individual steps make up stairwells. A tread and a riser make up each step. The tread is the flat portion of the shoe that you walk on. The riser is the vertical (up and down) component of the stairway between each tread.

The dog-legged staircase is the most cost-effective option. Two neighboring flights run parallel with a mid landing in this set of stairs.

When space is limited, a dog-legged staircase is usually installed, allowing for more efficient use of the existing area. This sort of staircase landing has a landing that corresponds to the level where the flight direction changes.

Features of Dog legged Staircase

1. In sectional elevation, it looks like a dog's leg.
2. It is always split into two fights.
3. The height of each flight is half the height of the floor.
4. The ratio of the height of each flight to the rise determines the number of risers in each combat.
5. The number of risers is equal to the number of trends in each flight.

Elements included in Dog-legged Staircase

1. Tread: Tread refers to the part of the staircase where the foot is placed.
2. A riser: is the section of the staircase that sits between two treads.
3. Newel post: The vertical post at the beginning and conclusion of the flight is known as a newel post.
4. Baluster: A baluster is vertical support erected across the length of a flight on which a handrail is supported to prevent a fall.
5. Handrail: A handrail is an inclined rail placed at an appropriate height to support a person when ascending or descending.
6. Landing: A landing is a platform that is offered to break the continuity of flight in order to provide respite to the user.
7. Pitch: is the angle formed by the line of nosing with the horizontal.
8. Nosing line: An imaginary line parallel to the stairwell's slope which connects the nosing of the staircase is referred to as the Nosing line.

How to determine the space required for this Dog-legged staircase?

In most institutional buildings, the tread measures 250–300 mm, while the riser measures 100–150 mm. The main stair in an institutional building must be 2.0 meters wide approximately.

Because the staircase we are designing is for a secondary purpose (rather than a primary one), we can lower the breadth of the stairs to fit the available space.

Take stair width = 4.5' = 1.372 m [There is no exact rule for determining stair width; it is dependent on the projected number of persons moving]

Width of landing = width of stairs = 1.372 m

Now, floor height = 12’ = 3.6585 m

Assume, riser = 6” = 0.1524 m [To get the number of steps in the whole number, a slighter greater than 0.15 m is assumed]

Number of riser = 12’ / 6” = 24 nos

Since dog-legged is assumed, take two number of flight.

Number of riser in each flight R = 24/2 = 12 nos

Number of tread = R – 1 = 11 nos. Width of tread = 600 – 2R = 600 – 2 * 152.4 = 295.2 mm

For construction easiness take 1’ = 304.8 mm.

So, going = 11 * 1’= 11’ = 3.354 m

Space required for staircase,

Length = entry space + going + landing = 1.372 + 3.354 + 1.372 = 6.098 m

[Entry space is the amount of space necessary before the step begins, and it is usually equal to landing space.]

Width = 2 * width of stairs (+ small gap) = 2 * 4.5’ = 9’ = 2.744 m.

To learn more, watch the following video tutorial.

Video Source: Civil Engineering Mastery

Advantages of Dog-Legged Staircase

1. The staircase has a simple design.
2. The drafting of the staircase is also simple and quick.
3. Space is more effectively utilized, resulting in less wasted space and greater carpet surface accessibility for use.
4. Because the top floor is not seen from below and the bottom floor is not visible from the top, the privacy of the floors is protected.
5. This sort of stairway can readily include architectural aspects.
6. The landing serves as a resting area, making commuting more convenient.

Disadvantages of Dog-Legged Staircase

1. The dog-legged staircase is incredibly tough to create.
2. Because railings are difficult to install, they should be planned properly.
3. Handrails are a crucial component of a staircase since they help with climb and descent.

Everything about the Dog-Legged Staircase