Redwood Vs. Pressure-Treated Wood

Wood is a common choice in material for constructing outdoor decking, railing and support posts. Different wood types, like redwood and pressure-treated wood, can be used for these applications.

Redwood comes from California's redwood forests, and is used for its aesthetic red appearance and beauty. A high grade type of redwood will resist insect harm and rot. A drawback to redwood is its high cost, so much so that redwood use is often kept at a minimum for only part of a construct that is visible.

Pressure-treated wood is normally made with pine or other softwood species and is typically infused with a chemical preservative called copper azole. This treatment allows the wood to be resistant to insects, bacteria and fungi. The cost of this wood can be 30 percent to 40 percent less than that of redwood.

Redwood contains tannin that gives it natural decay-resistance, but not all redwood products are equally protected, and many should not be used for ground contact or for structural applications. These days, a deck built with redwood usually has pressure-treated posts, beams, and joists (in addition to other structural elements) and reserves redwood for the decking, railing, and other highly visible components.