After discovering a water leak & associate rot in my bathroom wall/floor it was time for some serious demo. Had some people over and between the 4 of us we stripped it back to the walls.
I’d hoped to get the old tub out intact, but it quickly became obvious that the room was essentially built around it, and it wouldn’t come out without even more demo. So out came the sledgehammer, and the tub was reduced to bite-sized chunks that would fit out the window. I then discovered that there was no wall covering behind the tub, so that area had filled in with cellulose when I did blown-in insulation a few years ago.
Fortunately the insulation wasn’t near the leak and was dry. The stuff in the wall is also hard-packed enough that it is staying in place. I’ll use some blueboard to seal the wall back up before the shower unit goes in.
This let me expose the rotted area, and while it is bad, it is nowhere near as bad as feared. Only one of those vertical studs is load-bearing (though I found another load-bearing stud that was cut off 4 ft up so that needs fixing). and the damage to the beam is fairly contained. The joists took no structural rot, so I will sister them to be sure, but won’t have to replace them.
So out came the sawzall. The beam is 6"x6", I roughly cut a 4" x 33" x 1.5"deep section, and a smaller 4" x 12" x 1.5" deep section in the center of it. Once I chizel & sand to exactly those dimensions it will allow me to rip a pressure-treated 2x6 to a true 4" width, cut it to length and lay it in there. I think between wood hardener, epoxy glue and a bunch of 4" screws this beam will be nearly as strong as it was before. Then I have to sister the floor joists, cut out the 1" of rot on the top of the two and replace it with good wood, and build the two wall studs back down to the repaired beam.
Then I can replace the subfloor & wall covering in this corner and start making it look like a bathroom again.