We have a cantilevered deck extending 4 feet out the rear of the 2nd floor of our house, & running the entire 43-foot length. The cantilevered beams are 2x12 pt 16" o.c. The 2nd story roof above it does fully cover this deck, but water still gets on it whenever it rains due to the pool screen above it that causes rain drops to splash onto the decking, or when wind blows rain on it. Every wood material we've used for decking here has rotted within just a few years or less, because once it gets wet it tends to stay wet, even though the whole surface is slightly sloped outward. The bottom of the deck is standard porous aluminim soffit.
The question: What material would you use as a decking/ planking in this case, which can withstand years of being wet most of the time?
It seems this is almost the same situation as a flat-roof house.
About a year ago my dad installed plywood & painted it, & less than a year later the plywood's plys are separating, & it's starting to deteriorate & look bad very quickly.
Thank you ...