Vaguely similar questions have been asked, but I believe this situation is unique enough that I’m looking for some specific advice. I have a floor that is framed with 2x8s, 16 O.C., spanning roughly 11 feet between a central built-up beam and the outer sill plate. The joists “rest” on a standard (code minimum, blech) 2×2 ledger strip. The hardwood floors are a bit bouncy and it bugs me, so I plan to stiffen the floors by adding some sisters, or (more likely) gluing and screwing a bottom flange to the joists (to avoid removing tons of mechanicals and solid blocking).
However, before I do that I want to address the fact that the joists seem very shoddily connected to the beam. In addition to the ledger strip, about half of them are toe-nailed (see first pic, ok, that seems fine), but the other half are not (see second pic). This strikes me as very sketchy. There are a few end nails into each joist from the built up beam, and on some of the joists these seem to be carrying the whole load.
I thought about pounding some joist hangers in and then prying off the ledger strips, but my thinking is that the fact that half the joists are already toe-nailed to the beam means that adding joist hangers to these might cause splitting and I don’t want to raise inspection red flags by having a weird mix-and-match setup of hangers and ledger strip. Some of the non-toe-nailed joists have small gaps between joist and beam, and some aren’t even fully resting on the ledger (see pic 3, !). I do believe this was probably sloppy cuts rather than separation after the fact.
How can I improve these joist-beam connections? Should I just add some 45 degree toenails and call it good? The joists are fundamentally in good shape and if possible I'm looking for something DIY-able.
Edit: As I suspected, I was able to confirm that there are 3-4 end nails driven into the joists that are not toe-nailed at least (confirmed by feeling in the gap between joist and beam with a shim). Not sure if this changes anything.
Best Answer
If you need to remove the 2X2, then you will need to add joist hangers. The joist hangers available have stamped in the steel the nailing instruction for the hanger to perform the way it is designed. Many if not all hangers require "shear nail" in short, toenails as part of the nail sequence in each hanger.
If the 2X2 is not in the way, add cement coated 16D nails (3 1/2") even 12D nails 3 1/4" will work, a total of 5 in each end, 3 on one side, 2 on the other, situated roughly between the 3 on the other side.
If your span is over 8' (maybe 10') by code you will need bridging, diagonal or solid at the center point of the span. this will greatly reduce the springiness of the floor.