Using number 2 Southern Pine for floor joist, what is the size required for a span of 14 feet?

When determining the size of floor joists required for a specific span, it’s important to consider the type of wood, the spacing of the joists, and the load they are expected to support. Southern Pine is a commonly used species for structural applications due to its strength and stiffness.

For a span of 14 feet using number 2 Southern Pine, building codes and span tables indicate that a nominal size of 2x8 (which is generally referred to as 12x8 for its dimensional capacity) is appropriate. This size ensures that the joists can adequately support normal residential loads, which include both live loads (like people and furniture) and dead loads (like the weight of the materials themselves).

The other options, while they may be plausible diameters, do not meet the requirements for effectively spanning 14 feet with the necessary structural integrity for typical residential construction. Joists that are undersized may lead to issues such as excessive deflection or even structural failure over time. Thus, choosing the right dimensions is key to both safety and performance in construction.