They get wet. So will your deck... unless you are planning to cover it completely. I have no plans of permanently covering my deck. As the song says "they say it never rains in southern California, but man it pours." Well, it does. At least for a couple months anyway!
A couple points I'd like to hit here. Pressure treated lumber - I am going to use it for all my framing. I think you REALLY should too, even if your code says you don't have to. The lumber is the strength and support of a free-standing deck. If it fails, all this is for nothing.
There are different levels of "PT" lumber:
- Ground Contact
- Above Ground
All Lumber will be clearly marked with tags stapled on the end indicating which of these they are. This image is a label from an
article at familyhandyman.com called "Identifying Treated Lumber", which described the subject in great detail.
It's important that at least your post be Ground Contact. If your beams are within 18" of the ground you should probably make those ground contact too.
