I'm trying to replace a few sections of rotted bottom plate in my basement. I want to use pressure-treated lumber as it will be in contact with the concrete on 2 sides (and it still occasionally gets wet in one section, still trying to fix that,) but the basement was unfortunately framed in 2x3, and I can't find PT 2x3 anywhere nearby. Do I have any good options?
Rip a PT 2x4 down to size.
Use regular 2x3s, and treat the contacting faces with Copper-Green preservative (I already have a quart lying around)
Use regular 2x3s, and wrap the contacting faces in sheet plastic.
Would any of these work, or is there a better option?