One more: The stores won't cut pressure-treated for you -- "It's toxic". So you'll need a circular saw, and a good respirator, which may be hard to buy just now ...
Does anyone happen to know how toxic the new copper compounds are? Obviously they are toxic enough to microbes to make the wood rot resistant.
Also a fun fact I learned since our deck was originally built 15-20 years ago shortly after the switch-over to the new treated wood:
They needed to re-formulate the coatings they put on fasteners to hold up decent in the new treated wood. It took them a couple years to figure that out or at least for the knowledge to be widely known.
All the screws in our deck that I took out were corroded to the point that many of them looked more like toothpicks than screws when I removed them.