What is the calculated joist span for a building that is 9,600 mm wide by 12,800 mm long?

To determine the calculated joist span for a building that is 9,600 mm wide by 12,800 mm long, it is important to understand how joist span is defined. The joist span refers to the distance that a joist can span between supports, and it is generally influenced by factors including the spacing of the joists, the type of material being used, and the load that the joists will support.

In this case, we look at the width of the building (9,600 mm) and understand that the joists will typically run the shortest distance across the building's width, which allows for efficient load distribution and structural integrity. The calculated span would therefore relate to how far the joists can extend without additional support.

The chosen answer reflects a common practice in construction where spans are calculated based on both the materials and typical stressed values. A joist span of 4,474 mm is compatible with standard dimensions used in residential and light commercial construction, typically relying on conventional lumber or engineered wood products. It suggests that the given support structure and load conditions allow for this distance safely.

Therefore, the answer provided aligns with industry standards for joist spacing and spans, making it the appropriate choice for this specific structural scenario.