Cut out all the damaged subfloor, add blocking if needed, and bring the new floor up to match existing floor. I would glue down the new ply to the joists. For LVP, consider flattening out any inevitable height differences with planing/sanding, and fill gaps or divots with floor patch.
If there’s water damage under the sole plate, you might be able to remove it and replace, but as this is an exterior wall, it will be a PITA. Just add blocking and tie the new subfloor in there.
Hasz t1_j5pwp29 wrote
Reply to Water damage to subfloor. by CaptainPotato-Head
Cut out all the damaged subfloor, add blocking if needed, and bring the new floor up to match existing floor. I would glue down the new ply to the joists. For LVP, consider flattening out any inevitable height differences with planing/sanding, and fill gaps or divots with floor patch.
If there’s water damage under the sole plate, you might be able to remove it and replace, but as this is an exterior wall, it will be a PITA. Just add blocking and tie the new subfloor in there.