Dog-Legged Staircase Section Detail | RCC Stair Design Drawing

RCC Dog-Legged Staircase Details – Comprehensive Information Including Plan, Section, and Reinforcement

Introduction

This image provides detailed information about an RCC (Reinforced Cement Concrete) dog-legged staircase, covering the detailed plan, sectional view, reinforcement layout, and dimensional data. Such staircases are widely used in houses, duplexes, apartments, and commercial buildings because they are space-efficient and facilitate easy movement between floors.

This drawing includes the following elements:

• Staircase plan
• Staircase section
• Reinforcement details
• Landing details
• Staircase dimensions
• Riser and tread calculations

It is essential for architects, civil engineers, AutoCAD drafters, and construction professionals to understand these detailed specifications.

What is a dog-legged staircase?

This type of staircase consists of two flights running in opposite directions, connected by an intermediate landing. There is no open well between the flights, making it a compact staircase design suitable for small to medium-sized buildings.

Key Features

• Two parallel flights.
• Intermediate landing for a change in direction.
• Space-saving layout.
• Cost-effective construction.
• Suitable for residential and commercial projects.

Staircase Section Details

1. Lower Flight

The first flight starts at floor level (+0'-0") and ascends towards the landing.

• Total risers in the first flight: 10
• Tread width: 10 inches
• Riser height: 6.28 inches

The stair slab is inclined and is supported by the landing beam and the floor slab.

2. Landing

The landing is constructed at an intermediate height.

• Landing level: +5'-3"

Functions of the landing:

• Provides a resting space
• Changes the direction of travel
• Enhances safety
• Reduces fatigue while climbing the stairs

The width of the landing is equal to the width of the staircase (3'-6").

3. Upper Flight

The second flight extends from the landing level to the slab level.

• Remaining risers: 11
• Tread and riser dimensions remain the same
• Ends at the slab level (+11'-0")

Staircase Plan Details

The plan shows the following:

• Stair width = 3'-6"
• Two parallel flights
• Direction of movement indicated by arrows
• Landing located in the middle
• Total horizontal length = 11'-0"

Numbering the steps helps identify the positions of risers and reinforcement during construction.

Staircase Design Calculation

Riser Calculation

• Floor height = 11'-0"

Convert to inches:

• 11 × 12 = 132 inches
• Number of risers = 21

Riser height:

• 132 ÷ 21 = 6.28 inches
• Tread width
• Given tread = 10"
• Comfort check formula

According to staircase design standards:

• 2R + T

Substituting values:

• R = 6.28"
• T = 10"
• 2 × 6.28 + 10
• = 22.56"

This falls within the recommended comfort range for staircase proportions.

Reinforcement Details

The section drawing illustrates the reinforcement arrangement within the waist slab.

Main Reinforcement

• Main steel bars = 10 mm diameter.
• Placed along the slope of the staircase.

Purpose:

• Resists tension.
• Supports the load of the staircase.
• Prevents cracking.

Distribution Reinforcement

• 10 mm diameter stirrups
• Spacing = 6" c/c

Purpose:

• Distributes the load evenly
• Controls shrinkage cracks
• Enhances structural stability

Components shown in the image

1. Stair Tread

The horizontal part where the foot is placed.
Width = 10 inches

2. Riser

The vertical part between two treads.
Height = 6.28 inches

3. Landing

The flat platform between flights of stairs.
Width = 3'-6 inches

4. Waist Slab

The inclined RCC slab that supports the staircase.

5. Main Steel Bars

Placed along the slope of the staircase.

6. Support Wall/Beam

The black-colored wall shown in the section serves as a structural support.

Advantages of this staircase design

1. Space-saving

It requires less floor area compared to open-well staircases.

2. Cost-effective

Simple formwork and reinforcement reduce construction costs.

3. Ease of construction

It is easy to draft, design, and construct on-site.

4. Safe movement

The intermediate landing provides comfort and safety.

5. Ideal for residential buildings

Commonly used in:

• Duplex homes
• Apartments
• Villas
• Small commercial buildings

Construction Precautions

• Maintain uniform riser height.
• Ensure proper reinforcement cover.
• Use correct tread dimensions.
• Carry out adequate curing after casting.
• Check the staircase slope before shuttering.
• Ensure the landing level is correctly aligned.

Applications

Staircases of this type are generally used in the following locations:

• Residential buildings
• Duplex homes
• Apartment blocks
• Schools
• Office buildings
• Commercial complexes

Conclusion

As shown in the drawing, the staircase is a well-designed RCC dog-legged staircase featuring a comfortable riser height of 6.28 inches, a tread width of 10 inches, and a 3'-6" landing. The details provided in the section and plan clearly illustrate the structural arrangement, configuration, and reinforcement layout essential for safe and robust construction.

 Thanks to its compact design, cost-effectiveness, and ease of construction, this type of staircase is a preferred choice for modern homes and commercial buildings.