Structural recommendations for 3 story enclosed back porch?
Looking for some advice on an older 3-story enclosed back porch/stair structure.
I’ve had a couple different opinions and I’m a bit conflicted. One decking contractor pointed out several upgrades to strengthen things: joist hangers at small landings, lag bolts at ledger boards, hurricane ties, mending plates at top plates, sistering 2x6 stair stringers, doubling up joists at small landings, adding blocking at roof rafters, continuous 4x4 from ground to top landing, and possibly adding a support wall or posts to better transfer load down to concrete.
Another contractor came out and said none of that was really necessary because the joists go into the building and there are no visible signs of sagging/cracking/stress.
But when you walk up and down the stairs, you can definitely feel and hear vibration. I agree it’s not actively failing, but it also doesn’t feel as solid as I’d like it to.
I do want to do some reinforcement if there are obvious things here that would improve safety and strength of the structure. If anyone with porch/framing/deck/structural experience can look at this and say, “Yes, I’d add XYZ,” I’d really appreciate the advice.
Edit: the newer 2x4s are just so the new siding had something to nail into. Not structural at all.