R317.1.3 Geographical Areas
In geographical areas where experience has demonstrated a specific need, approved naturally durable or pressure-preservative-treated wood shall be used for those portions of wood members that form the structural supports of buildings, balconies, porches or similar permanent building appurtenances where those members are exposed to the weather without adequate protection from a roof, eave, overhang or other covering that would prevent moisture or water accumulation on the surface or at joints between members. Depending on local experience, such members typically include:
- Horizontal members such as girders, joists and decking.
- Vertical members such as posts, poles and columns.
- Both horizontal and vertical members.