What does the tread depth refer to?

Tread depth specifically refers to the horizontal distance from the front to the back of a stair tread. This measurement is crucial for assessing the safety and comfort of stairways, as it determines how much space is available for a person's foot when stepping onto the tread. Adequate tread depth helps prevent slips and falls, as well as providing a stable surface for users.

In the context of architectural and safety standards, having a proper tread depth is essential for ensuring that stairways are usable and compliant with regulations. Standards often dictate minimum tread depth dimensions to promote safety in construction practices.