I built a deck more than 25 years ago and used construction spruce for the beams and joists—not pressure-treated wood. I put strips of tar paper about 3 in. wide on top of the 2×6 joists, then fastened the white-cedar decking with galvanized nails. The cedar has rotted, so I am replacing it. But the spruce, protected by the tar paper, is still in excellent shape. I live in Ontario, where there is lots of snow, and the deck has been exposed to it for all those years. This simple detail allowed me to avoid using the more toxic pressure-treated wood.
John McCubbin, Warsaw, None