Rotten Subfloor goes under support post of my lanai Roof. Best recommendation so far is to cut 3/4 inch thick end off a 2x4 (post is a 4x4) hammer under one side, scrape/chisel out other side of rotten subfloor under post, add another 2/4 "shim". then simply cut new subfloor around 4x4 post.
Can't figure out how to post pics, but I have em...