01The problem
The floor beside the tub flexed underfoot. Once the finished floor came up, the plywood underneath was dark and delaminating along the tub edge — a slow leak that had been wicking into the subfloor long enough to spread past the visible area.
02What we did
We cut the damaged plywood out back to sound joists, let it dry, and cut and fitted new subfloor around the tub and toilet flange. The fiddly part is the cutting: nothing in a bathroom is a straight line, and every piece has to be scribed rather than measured.
03The result
A solid floor to build back on. We would rather find this and tell you than lay a beautiful new floor over wet plywood.