Originally Posted by KAttkisson
Has anybody out there removed the rotten particle board and floated the removed area with some type of resin or epoxy? There is sheet steel under it to serve as a form.
I've replaced flooring in my 1974 mobile home, and it is really not fun. Unless you absolutely must replace the particleboard (think hole in it), I'd recommend drying it out like homeless said, but I'd use an oil-based primer on it after its 100% dry. I had a water line in the front bathroom blowout last year, and the paint REALLY added firmness to the floor compared to before it got wet. Plus the primer will seal any mildew smells.
As a precaution, maybe use a thin sheet of fir over the primed wood. Its light weight compared to plywood. (Ply is stronger though.) Just my .02 cents worth.