While remodeling my bathroom and checking the floors for level, I noticed one corner of the bathroom had a 1/2" dip. I went to inspect the joists from underneath in the basement and found that a floor joist had been cut to make room for the toilet drain pipe. Hoping my terminology here is accurate. It looks like this repair consisted of installing 2 pieces of 2×8" with one end supported by the rim(?) of the house and the other attached to the adjacent uncut joist using a joist hanger (Simpson strong tie LUS26Z). The joist hangers were secured using drywall screws! One end of the 2x8s are lower than the supporting joist, where this must be the cause of my 1/2" dip.
My question is how do I go about remedying this issue? Ideally I'd sister the joist but the drain pipe is in the way. Aside from using drywall screws, is the repair sufficient?
I was thinking to remove the screws and replace them with these nails, doing the replacement one screw at a time. It's worth noting that the original joist has a crack towards the bottom edge of it where the hanger is attached. Should I be concerned about a nail causing the split to worsen?
I should add that the joists in my home are 2×10”, 16” on-center. The steel beam shown below is less than 3'-0" away from the 2x8s.
Best Answer
No need to worry about sistering that joist. Since the headers are less than 3' away from that black, steel beam support, IRC R502.10 indicates that the single trimmer is adequate:
The low header is obviously the cause of your floor dip. It can be difficult to get them pushed up to the proper elevation, especially if you're a plumber. A post (a 2x4 would work) and some sort of jack (a car jack or even a wedge would work) will get it up to the top-of-joist elevation. The joist hanger toe-nails are going to be painful to remove (unless they are drywall screws too), but they need to get pulled back out of the trimmer to allow the header to move up to the correct elevation. Rather than remove the joist hangers from the trimmer, you can insert a wood spacer between bottom-of-hanger and each header if you prefer.
Don't worry about the split joist. It has 2 neighbors to make up for any strength loss from stuff like that.
Different Simpson hangers call for different nail schedules. Your LUS26Z calls for 4 - 0.148" x 3" face nails into the joist and for 4 - 0.148" x 3" toe nails through the header and the joist. Since you don't have a double trimmer for the 3" face nails, obviously you'll have to use 1-1/2" fasteners instead (Simpson makes 1-1/2" nails with the 0.148" diameter--that's a 10d common nail's diameter). The substitution will cost you 23% of the connection strength. Assuming your joists are 20 ft long or shorter, there will still be sufficient strength. You can find the nail schedule yourself by searching for "LUS26" within the full catalog linked from https://www.strongtie.com/resources/literature/wood-construction-connectors-catalog.
If you intend to substitute Simpson's screws for standard nails, #9 x 1-1/2" screws substitute for the face nails and #9 x 2-1/2" screws substitute for the toe nails.
And put some sort of electrical insulator between the bottom of that joist hanger and that copper pipe. And verify that all of those joist hangers have the same markings. One of them doesn't look the same as the others.