Do I need to use PT deck boards
taos
| Posted in General Questions on
I live in the high desert and am going to build a deck. Humidity is very low and the deck will be on the southeast side of the house. The lumber company says that I don’t need pressure treated deck boards. I’m going to use UV protectant sealer on all sides and ends, and will do yearly maintenance. What is your take for using untreated Southern Yellow Pine deck boards? (They will be 2×6, not 5/4.)
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I'm in Montana, also high alpine desert / dry.
I wouldn't use PT, mostly because I don't think PT lumber looks great, but also I don't think it's necessary. You might price out cedar decking, something like western red cedar or Alaskan yellow cedar - it'd probably last longer, and at least in my area Alaskan yellow is relatively inexpensive.
Also - and this is just personal preference - I hate refinishing decks, so I leave my Alaskan yellow cedar deck untreated and just let it grey out in the weather.
taos,
I look at wood decking as a sacrificial layer, the lifespan of which varies with climate and materials. The main thing to concentrate on is that the structure below is durable and will last without issues for a good 40 years, and is detailed so the periodic removal of the decking is easy and doesn't necessitate a lot of extra work to get at. If you want the deck surface to last as long as the structure then pavers are probably a better option.
I almost never specify pressure treated decking, and I almost never use synthetic decking. There are many types of wood that are naturally somewhat-to-very rot-resistant without treatment. You can also get lumber that is thermally modified or acidically modified to be very rot-resistant and maintains a nicer-looking surface than typical pressure treated lumber.