Stair terminology — name of vertical members between steps and the handrail In staircase construction, what are the vertical members fixed between the treads/steps and the handrail that support the railing system called?

Introduction / Context:
A stair balustrade provides safety, guidance, and visual definition to stair flights and landings. Understanding the correct terms for its components is essential for specifying materials, spacing, and code compliance, especially for child-safety and fall-protection requirements.

Given Data / Assumptions:

• The question concerns the vertical posts that connect steps (or a string/landing) to the handrail.
• Standard stair elements are assumed: treads, risers, strings, newel posts, balusters, and handrails.

Concept / Approach:
Balusters (also known as spindles) are the small vertical members that support the handrail and restrict openings. A newel post is the larger, primary vertical post at the ends or turns of a staircase. A string (or stringer) is the inclined structural member supporting the treads and risers. Soffit refers to the underside of the staircase (finish or structural surface). Only “balusters” accurately names the vertical infill posts between the steps and the handrail.

Step-by-Step Solution:

Verification / Alternative check:
Building codes define baluster spacing (e.g., maximum gap rules) to prevent child entrapment or falls, reinforcing that these are the small vertical members under the handrail.

Why Other Options Are Wrong:

• strings: inclined structural supports, not vertical infill members.
• newel posts: few large anchoring posts, not multiple small members.
• soffits: underside of stairs, not part of the railing.

Common Pitfalls:
Confusing “newel” and “baluster”; using “balustrade” (the whole assembly) when the question asks for the individual vertical members.

Final Answer:
balusters