Does wet drywall always need to be replaced?

The call is made with moisture meters, not eyeballs. Drywall wicks water upward from the floor, so a wall can read wet two feet up while looking dry — that is why crews map the moisture line before deciding. If readings show the panel can reach dry standard fast enough to beat microbial growth, drying in place with air movers and (where needed) weep holes or removed baseboard is the less invasive, less costly path.

Replacement is the right call when: the water was Category 3 (sewage or floodwater — porous materials cannot be sanitized), the drywall sat saturated for days, the panel has physically swollen, sagged, or lost its structure, or insulation behind it is soaked (wet insulation holds moisture against the back of the panel and gets pulled).

The common industry practice for standing-water losses is a "flood cut" — removing the bottom section of drywall a set height above the water line so the wall cavity can dry and be inspected, then patching that band during rebuild. It looks dramatic; it is far cheaper than replacing whole walls, and it is how hidden cavity mold gets prevented.