Over-logging of softwoods prior to the 1960s resulted in a diminished supply of decking material, but by then pressured treated (PT) pine was on the market. Today, most pressure treated wood is Southern Yellow pine, which is chemically protected through a process called pressure treating. This process helps guard against insect damage, mold, microorganisms and fungal decay. For decades, manufacturers infused the wood with the chemical chromated copper arsenate (CCA), a suspected carcinogen, to protect the wood, but today, pressured treated lumber is treated with less-toxic chemicals.
Pressured treated wood decking is stainable and durable, but not all is created equal. Bad quality pressure treated decking can be full of moisture. If so, it will shrink and twist, and it will be heavier than a better quality decking.
If you decide to use pressure treated decking to build a wood deck consider using choice, premium, or select treated decking. It costs more than a lesser quality wood decking but it will have fewer knots, straighter grains, and is kiln-dried before and after treatment so it will have less tendency to warp.
Pressure treated decking is used in 75% of all decks built today. In fact, according to popularmechanics.com “the understructure frame—posts, beams, joists—of virtually every deck is made of PT lumber.”
A wood deck built with pressured treated decking will last 15 – 20 years depending on the quality of decking material used, and with proper care. Maintenance on wooden decks require more care, effort, and expense. To properly maintain a wooden deck with rail, it should be power washed annually — by a professional. Further if you build a wood deck plan on staining it, or having it stained, or coated with a clear wood preservative every two or three years.
Although the initial cost of pressure treated decking material is about 40 – 50% less expensive than other alternatives, like composite decking or exotic wood decking, the labor to build a PT wood deck and maintain it over the years often makes up for the materials cost savings.