What are treads and risers supported by?

What Structural Elements Support Treads and Risers in a Staircase?

Primarily, the structural backbone that supports the treads (horizontal steps) and risers (vertical boards between steps) in a staircase is the stringer. However, other components, like carriages or a combination of stringers and support walls, can also play a vital role depending on the staircase design and building codes.

Summary

The stringer, typically a sturdy board notched to accommodate treads and risers, forms the primary support structure for most staircases. In some designs, carriages, which are similar to stringers but have the treads and risers attached between them, may be used. Additionally, support walls can provide additional structural support, particularly for stairs built against a wall.

In-Depth Explanation

Stringers: The Staircase Backbone

• The most common support structure for treads and risers.
• Typically, two or three stringers are used, depending on the width of the staircase and building code requirements.
• Stringers can be made of various materials, such as wood, steel, or concrete, depending on the design and load requirements.
• They are notched or routed to create a precise fit for the treads and risers, ensuring stability and structural integrity.

Carriages: An Alternative Support Structure

• Less common than stringers but often used in open-riser staircases or where a more contemporary look is desired.
• Consist of two parallel boards with the treads and risers attached between them, creating a visually lighter and more open feel.
• Require precise fabrication and installation to ensure adequate support and structural soundness.

Support Walls: Additional Structural Support

• Can be used in conjunction with stringers, especially for staircases built against a wall.
• Provide lateral support to the stringers, enhancing the overall stability of the staircase.
• May be required by building codes, especially for wider staircases or those with heavy loads.

Other Factors Influencing Support Structures:

• Staircase Design: The type of staircase (straight, curved, spiral, etc.) and its design aesthetic influence the choice of support structures.
• Building Codes: Local building codes dictate minimum requirements for staircase structural elements, including stringers, carriages, and support walls, to ensure safety and load-bearing capacity.
• Materials: The choice of materials for treads, risers, and support structures affects the overall structural design and load distribution.

Conclusion:

In conclusion, while stringers are the most prevalent support structure for treads and risers in staircases, other elements like carriages and support walls can also play a critical role. The specific combination of structural elements used depends on various factors, including staircase design, building codes, and material choices. It’s essential to consult with a qualified professional to ensure your staircase is designed and built to meet all safety and structural requirements.