Which of the following is a common deck framing issue?

Joist spacing is a common deck framing issue because it directly affects the structural integrity and safety of the deck. Proper spacing ensures that the load is evenly distributed and prevents issues such as sagging or uneven surfaces. Building codes often specify maximum joist spacing to maintain strength and support for the deck surface and any load it may bear, such as furniture or occupants.

When joists are spaced too far apart, the deck may not be able to support the intended loads, leading to potential safety hazards. Conversely, if the spacing is too tight, it may lead to unnecessary material usage and increased project costs without significant benefit.

The other options do involve considerations in deck construction, but they do not primarily pertain to framing issues. Deck railing design is more about safety and aesthetics, post material pertains to the vertical supports rather than the framing itself, and siding thickness is related to the exterior finishing rather than the structural elements of the deck. Thus, joist spacing is undeniably key in framing discussions.