Staircase Reinforcement

EN 1991-1-1 Eurocode 1: Actions on structures - Part 1-1: General actions - Densities, self-weight, imposed loads for buildings, and EN 1992-1-1 Eurocode 2: Design of concrete structures - Part 1-1: General rules and rules for buildings specify the requirements for the height of stair risers in Europe. According to EN 1991-1-1, the minimum height for stair risers should be 150 mm, and the maximum height should not exceed 190 mm for residential buildings. For non-residential buildings, the maximum height can be extended up to 200 mm. EN 1992-1-1 provides additional guidance on the design of staircases, considering factors such as safety, comfort, and usability. It recommends avoiding abrupt changes in riser heights and ensuring a consistent rise throughout the staircase. Keep in mind that these values are only recommendations, and national building codes or local regulations may have specific requirements that need to be followed. It is advisable to consult the relevant codes and regulations applicable in your country or region for precise guidelines on stair riser heights.

To calculate the loads on stairs according to Eurocodes, you need to consider two main load cases: permanent loads and variable loads.

1. Permanent Loads:
- Self-weight of the staircase: Calculate the weight of the structural elements of the staircase, including treads, risers, stringers, and handrails, based on their dimensions and material properties. - Imposed loads: Determine the loads that are permanently acting on the stairs, such as the weight of the finishing materials, partitions, and fixed installations.
2. Variable Loads:
- Live loads: Determine the loads expected due to the occupancy of the building. It is essential to consider the intended use of the stairs, as different occupancy categories have different load requirements. For example, a residential staircase may have a lower load requirement compared to a commercial or public staircase. Refer to the Eurocode EN 1
3. 990 for guidance on minimum imposed loads for different occupancy categories.
- Snow loads: If the staircase is exposed to snow, calculate the snow load based on the geographical location and the annual snowfall. Eurocode EN 1
4. 991 provides guidance on snow load calculations for different regions.
Once you have determined the various loads, you need to consider their combinations according to Eurocode EN 19
5. The code provides different combinations based on the type of loading and their probability of occurrence. These combinations will help you determine the critical load cases for design.
It is also essential to consult the specific national annex of your country, as it may provide additional guidelines and modifications to the Eurocodes to ensure compliance with local regulations. Overall, calculating loads on stairs according to Eurocodes requires understanding the specific load cases, considering the appropriate load factors, and following the design codes and national annexes for accurate and safe design.

The design of a staircase using the Eurocodes should include the calculation of the loads, design of the structure, selection of the materials, and the verification of the structure by multiple tests.

1. Calculate the loads - Determine the type of forces applied to the staircase and calculate their magnitude using the appropriate Eurocode documents. Calculate the static loads, dynamic loads, wind loads, and other external loads.
2. Design of the structure - Use the Eurocodes to select the most suitable type of staircase for the required application. Determine the size and shape of the steps, risers, stringers and any other components.
3. Select the materials - Design the staircase in accordance with the Eurocodes and select the appropriate materials. Consider the strength, cost and durability of the materials, as well as any applicable regulations.
4. Verification of the structure - Perform brittle fracture, static load, dynamic load, wind and other tests to verify the strength and durability of the staircase. Check the design to make sure it meets the requirements of the Eurocodes.

The amount of reinforcement needed for a staircase depends on the type of stairs, the design load, the size of the stairs, and the structural materials used. To determine the exact amount of reinforcement needed for your staircase, consult with a structural engineer or use an online calculator. Generally, horizontal and vertical reinforcing bars should be placed at the center of the stair stringers, while a continuous bar should be used at the edge of each tread or riser. The reinforcing bar size should be based on the design load and the size of the stairs. It is also recommended that the bars be tied together to provide added stability.

Reinforcement in a cantilever staircase can be shown with metal rods, structural steel, brackets, or other forms of metal support. Usually, these pieces of metal are embedded into the concrete foundation beneath the stairs, and may include additional support under each step or at the connection points between the treads and risers. The reinforcement should be made visible by either painting it a different color than the rest of the stairs or by wrapping it in a protective material.

Hanger bars are commonly used in waste slabs in staircases to provide a secure base to which the waste slab can be attached. This helps ensure that the slab remains in place and that it is properly supported. The hanger bars provide a secure and stable connection between the waste slab and the staircase structure, helping to reduce vibrations and noise. Additionally, the hanger bars help to reduce any potential sagging of the slab over time.

1. Determine the height and length of your stair.
2. Calculate the rise and run of each step: the ideal rise of a step is between 150 to 160mm and the ideal run of a step is between 250 to 280mm.
3. Design the stair landings: the minimum width of a landing should be equal to the stair width and the minimum length of a landing should be equal to twice the step height plus the step run.
4. Calculate the size of the stair treads and risers: the minimum size of a stair tread should be 200mm and the minimum size of a stair riser should be 175mm.
5. Determine the reinforcement details: the stair landings and treads should be reinforced with steel bars and stirrups on each side.
6. Design the formwork details: the formwork details should be designed based on the concrete pours and the desired stair finish.
7. Calculate the quantities of concrete required: the amount of concrete required can be estimated from the stair measurements and formwork details.
8. Calculate the required elements for fire resistance: if it is a public stair, it should be designed for a minimum fire resistance of 30 minutes.
9. Design the stair details according to the Eurocode 2 standard: the design should include the details of the reinforced concrete, formwork, and fire-resistance for the stair.
10. Calculate the cost of the project: the cost of the project should include the cost of the materials, labor, and resources.

1. Calculate the Width of the Staircase: The width of the staircase should be calculated based on the width of the tread and the number of risers. According to Eurocode 2, the minimum width of a staircase should be between 1.1 m and 1.2 m.
2. Calculate the Height of the Staircase: The height of the staircase should be calculated depending on the number of risers. According to Eurocode 2, the tread should have a minimum height of 16 cm and a maximum height of 22 cm.
3. Calculate the Number of Treads: The number of treads for the staircase should be calculated depending on the total height of the staircase. According to Eurocode 2, the minimum number of treads is two per meter.
4. Calculate the Pitch of the Staircase: The pitch of the staircase should be calculated based on the angle between the tread and the riser. According to Eurocode 2, the minimum pitch of a staircase should be between 30 degrees and 45 degrees.
5. Calculate the Riser Height: The riser height should be calculated based on the total height of the staircase. According to Eurocode 2, the minimum riser height should be between 15 cm and 16 cm.
6. Calculate the Tread Depth: The tread depth should be calculated based on the width of the staircase. According to Eurocode 2, the minimum tread depth should be between 25 cm and 30 cm.
7. Calculate the Handrail Specifications: The handrail specifications should be calculated based on the width and depth of the staircase. According to Eurocode 2, the handrail must have a minimum height of 0.9 m and must be continuous along the entire length of the staircase.