We have a preexisting deck above where we want to put a stone/concrete patio below. The existing footing are differing heights and in general are lower (6-12") lower then where we'd like the patio to be at. This leaves us needing to make adjustments to the deck post that will eventually have to be replaced (20+ years hopefully).

What is the best way to build the patio to not prematurely rot out these posts? Better to use pavers then concrete?

Should we do pavers so redoing the post in years to come won't involve busting up concrete? or would using pavers just rot the wood out sooner since there would be more water retained in the area?

Is there something I could wrap the posts with that would protect them?

More importantly, is there a cost effective approach?