We live in Toronto and are replacing our 17-year-old deck made with pressure-treated wood. Our challenge: being on the mostly shaded, north side of the house, our present deck retains moisture, moulds, dirt and all finishes peel off. We thought using composite decking material would be the answer, but a quick review suggests it brings its own problems. Has anyone had success with composite decking under these conditions? Is there a wood solution that would work?