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12.1.2. Drawing different types of staircases – Dog legged, Open well – plan and section
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Today, we're exploring the dog-legged staircase design. This staircase typically has two straight runs with a landing in between. Does anyone know why this design is popular in buildings?
Maybe because it saves space?
Exactly! The dog-legged design maximizes space efficiency. Can you remember the standard tread and riser dimensions we use?
I recall the tread is 300mm, and the riser is 150mm.
Very good! Now, let's recap the overall dimensions of the staircase we need. Can anyone remind me of those?
The dimensions are 3m by 5.5m with a vertical height of 3.3m.
Correct! This information is essential for our drawings. Remember: DRAWS for Dimensions, Riser, and Width of Stair.
To summarize, the dog-legged staircase features specific dimensions and is chosen for its space efficiency in buildings.
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Next, let’s shift our focus to the open well staircase. Can anyone explain what an open well is in this context?
Isn't it like a rectangular opening in the middle of the staircase?
That's right! The open well allows for more light and air. How are its dimensions different from the dog-legged staircase?
It has dimensions of 4.5m by 5.4m and a height of 3.6m.
You've got it! And what about the materials used? What’s the thickness of the waist slab?
It's 150mm, just like the others.
Excellent! Reinforcement details like main steel 12ϕ@150 c/c are also crucial. Remember: LIGHT for Light, Internal dimensions, and Guides the layout.
Summary: Open well staircases feature greater dimensions and provide enhanced lighting as a design element. Keep these details in mind when planning.
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Let's discuss the reinforcement techniques for both staircase types. Why is reinforcement vital?
To ensure the strength and stability of the staircase!
Exactly! For our dog-legged staircase, we use main steel of 10ϕ@125 c/c spacing. What about for the open well staircase?
It uses 12ϕ@150 c/c spacing!
Correct! Why do you think different diameters or spacing might be used?
It could be because of the different loads or designs on the two types.
Yes, perfectly said! Remember: STRENGTH for Spacing, Type, Reinforcement, and Effective load management.
In summary, reinforcement varies based on the design requirements, and each design needs to consider its specific load and dimensions.
Overview
Short Summary
This section focuses on the design and drawing of two types of staircases: dog-legged and open-well, along with required measurements and specifications.
Medium Summary
The section covers the essential techniques for drawing a dog-legged and an open-well staircase, detailing specific measurements, design requirements, and reinforcement details for each type of staircase relevant to building planning.
Detailed Summary
Detailed Summary
This section discusses two distinct types of staircases used in architecture: the dog-legged and open-well staircases. It outlines the design principles and specific measurements necessary for constructing these staircases in a reinforced concrete context.
Key Types:
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Dog Legged Staircase: This type is characterized by its L-shape and is commonly used in residential and office buildings. The design focuses on two straight runs of steps connected by a landing.
- Dimensions: 3m x 5.5m, vertical height of 3.3m
- Slab thickness: 150mm
- Tread: 300mm, Riser: 150mm.
- Stair width: 1.5m
- Reinforcement: Main steel 10ϕ@125 c/c, distribution 8ϕ@250 c/c.
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Open Well Staircase: This staircase features an open well design, allowing more light and air. It can have various forms but typically incorporates a rectangular well.
- Dimensions: 4.5m x 5.4m, vertical height of 3.6m
- Slab thickness: 150mm
- Tread: 300mm, Riser: 150mm.
- Stair width: 1.5m
- Reinforcement: Main steel 12ϕ@150 c/c, distribution 8ϕ@250 c/c.
The section is critical as it provides HVAC engineers with the knowledge to create functional and safe staircases in their designs.
Audio Book
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Create a free accountDraw plan and sectional elevation of RCC dog legged staircase for an office building which measures 3m x 5.5m. The vertical distance between the floor is 3.3m (including landing). Thickness of the floor slab is 150mm. Provide steps with tread of 300mm and rise of 150mm. Thickness of waist slab and landing slab is 150mm. Width of stair is 1.5m. Reinforcement details: main steel: 10ϕ@125c/c spacing and distribution: 8ϕ@ 250 c/c spacing.
Detailed Explanation
The dog legged staircase in this exercise has a specific design meant for office buildings. Its dimensions are 3 meters by 5.5 meters, meaning it occupies a rectangular area of that size. The total height between floors, which includes the landing area, is 3.3 meters. The floor slab, which is the horizontal surface that supports the staircase, has a thickness of 150 millimeters. Each step consists of a tread, which is the part you step on, measuring 300 millimeters wide, and a rise, which is the vertical part of the step, at 150 millimeters. Both the waist slab and landing slab also have a thickness of 150 millimeters, and the overall width of the staircase is 1.5 meters. Reinforcement of the stairs involves using main steel bars with a diameter of 10mm spaced 125mm apart, and additional distribution steel bars of 8mm spaced 250mm apart, to ensure structural strength and durability.
Examples & Analogies
Think of the dog legged staircase like a set of steps leading to an office building. Imagine walking up stairs where each step feels sturdy; that’s because they are designed with specific measurements in mind—like how a ladder has to be strong enough to hold your weight. The dimensions and materials are carefully chosen to prevent accidents and ensure comfort, just as builders would carefully select materials for a heavy-duty ladder.
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Create a free accountDraw plan and sectional elevation of an open newel staircase with a rectangular well for an office building with the following data: Inside dimensions of staircase = 4.5m x 5.4m. Height between the floors is 3.6m. Thickness of the floor slab and landing slab is 150mm. Width of landing=1.5m. Width of stair = 1.5m. Tread=300mm, riser=150mm. Waist slab thickness = 150mm. Reinforcement details: Main steel: 12ϕ@150 c/c spacing and Distribution: 8ϕ @ 250 c/c spacing.
Detailed Explanation
The open newel staircase is designed with a rectangular well, a design choice that provides more visibility and an open feel around the stairs. The inside dimensions, which determine how much space is available for the stairs, are specified as 4.5 meters by 5.4 meters and the height between floors is 3.6 meters. This staircase also has floor slabs and landing slabs each 150 millimeters thick, similar to the dog legged staircase. Width of both the landing and stair is set at 1.5 meters. The treads measure 300 millimeters while the risers measure 150 millimeters, contributing to the stair's overall usability. For structural support, main steel bars with a diameter of 12mm are spaced 150mm apart while distribution bars of 8mm are spaced 250mm apart.
Examples & Analogies
Picture this open newel staircase as a beautiful open-air spiral stairway in a modern office. Just as we might see in a stylish home, this design not only serves a purpose but also enhances the aesthetic appeal of the area. This staircase allows light and space to flow around it, similar to how an open window invites fresh air and light into a room, making the environment feel warmer and more inviting.
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Key concepts
Core takeaways and short definitions to help you quickly recall the key ideas from this section.
- Dog Legged Staircase:
A design feature that allows for space efficiency in building layouts.
- Open Well Staircase:
A staircase type that enhances lighting and ventilation.
- Reinforcement:
Crucial for the structural integrity of staircase designs.
Examples
Memory aids
Once there was a building with a dog legged staircase, where each step up was a race, but also an open space awaited on high, filled with light, far and nigh.
Flash Cards
Glossary
Dog Legged Staircase
A staircase with two straight flights connected by a landing, forming an L-shape.
Open Well Staircase
A staircase design featuring an open space in the middle, allowing for light and ventilation.
Reinforcement
Steel bars or mesh used to strengthen concrete.
Riser
The vertical distance between two consecutive treads.
Tread
The horizontal part of the stair on which one steps.