I have a walk out basement with a covered screened in deck on the upper level. The 3 support posts have developed dry rot and removing the entire post is not an option. These posts run the entire hight of the deck, around 20 feet. I also need to redo the concrete support posts below each post. I was thinking of renting a post jack used to jack up decks and lift the deck just enough to cut out the dry rot and dig up and replace the concrete posts. My question is what is the best method to join the spliced in piece with the old posts. I figured to just cut up far enough to remove the dry rot then either butt join the 2 sections and use steel plates to join or use an overlapping joint between the 2.

What method is best and what do I need to consider when jacking up a deck to repair posts and concrete support? What kind of concrete should I use, add rebar? How long should I let the concrete cure before setting deck back down on it?

Thanks. I am just a little nervous jacking up a deck and leaving it that way a few days while I do the work.