What is the minimum tread length required on a staircase?

The minimum tread length required on a staircase is important for ensuring safety and usability. For residential staircases, the building code typically specifies that the minimum tread depth is 10 inches. This measurement ensures that there is sufficient space for a person's foot to rest securely while ascending or descending the stairs, reducing the risk of slips and falls.

A tread depth of 10 inches strikes a balance between functionality and safety, allowing users of various foot sizes to navigate the stairs comfortably. Codes may vary slightly based on local regulations, but 10 inches is a commonly accepted standard across many jurisdictions.

Other options listed appear to either exceed the minimum requirement or fail to meet it. For example, while 9.5 inches might seem feasible, it does not comply with the safety standards that specify a minimum of 10 inches. Therefore, the choice of 10 inches aligns with established building codes, making it the correct and safest answer for minimum tread length requirements on a staircase.