Symptoms
- Wall or ceiling drywall feels soft, spongy, or sags when pressed
- Visible bulging, staining, or bubbling paint
- Sometimes a musty smell or visible mold
Likely causes
- CommonActive or recent plumbing leak inside the wall or ceilingPipes running through walls can leak slowly for a long time before it's noticed.
- CommonRoof or window leak allowing water into the wall cavityWater traveling from a roof or window leak can saturate drywall some distance from the actual entry point.
- PossibleChronic high humidity without an active leakIn extreme cases, sustained high humidity alone can weaken drywall paper over a long time.
What to do
- Identify and stop the water source first; wet drywall will just get worse if the leak continues.
- Turn off water to the affected area if a plumbing leak is suspected until it can be found and repaired.
- Cut away the wet section of drywall back to dry, solid material, typically cutting along stud or joist lines.
- Inspect the framing and insulation behind the drywall for mold or ongoing dampness before closing it back up.
- Dry the wall cavity thoroughly with fans before installing new drywall, which may take a day or more.
- Replace insulation that got wet, since wet insulation loses effectiveness and can hold mold.
- Install new drywall, tape, and finish once everything behind it is confirmed dry, and repaint to match.
Tools and parts
- Utility knife
- Drywall saw
- Fans
Replacement drywallSearch: “drywall sheet”
InsulationSearch: “wall insulation batt”
When to call a pro
Call a plumber to fix the leak source and a contractor or water damage company for larger repairs.
Safety
Use caution
Wear a mask when cutting out wet or moldy drywall, and turn off nearby electrical circuits if water is near outlets or wiring.