Working on a 90s bathroom repair. Shower had a slow leak below it which resulted in some mold stained subflooing. It still seems fairly solid/has no flex and is 3/4" OSB.
We've sprayed to kill the mold and are considering if spraying it with killz and laminating another piece of half inch plywood overtop would be enough or if we should cut down to joists and install new 3/4" with blocking.
Pic attached
https://drive.google.com/file/d/1TDr3hMDZKq9tmP3UtykDe9SVQEUF9z0B/view?usp=drivesdk