What are the signs that indicate a rotted subfloor and how can it be repaired effectively?

Signs of a rotted subfloor include sagging or uneven floors, soft spots, musty odors, and visible mold or mildew. To repair a rotted subfloor effectively, the damaged area should be cut out and replaced with new plywood or OSB. It's important to address the source of the moisture that caused the rot to prevent future damage.