I'm sure most know this but even treated wood exposed in the sun and weather must have a treatment of paint or other protection or it will degrade and start to splinter. I was warned of this and also experienced it. My deck, which is half covered with a roof was covered with a deck stain just I after built. Over the years, about 12, the roofed part of the deck has held up like it was new but the other half started to splinter. I gave the sun exposed half a treatment this spring but it was like closing the barn door after the horse was out of the barn.
