I'm ready to replace my decking on my ground level deck made with pressure treated lumber. The area gets little sunlight after the morning hours and, consequently, the boards get moldy. Because it is so shady and close to the house, I'm hesitant to power wash it often because of the massive amount of water that sits on the ground with little ventilation. I'm considering composite decking but I've been told that shade is shade and any material will get moldy eventually. However, if I didn't have to pressure wash but could use a simple bleach and water mixture, that would keep the area from being so damp after cleanup. The deck abuts a stone retaining wall at the bottom of a hillside.

My contractor recommends a concrete decking but that would cause huge problems in the event something like a drain under the deck would need repair.

Any advice would be greatly appreciated.