Drywall is gypsum wrapped in paper — both soak up water like a sponge and both feed mold. Whether it can be saved is a judgment call best made with a moisture meter, not by eye.
Signs of water-damaged drywall
- Brown or yellow staining, rings, or discoloration
- Sagging, bulging, or a spongy/soft feel when pressed
- Bubbling, cracking, or peeling paint
- A musty smell, or visible mold spotting
- Crumbling or a chalky texture where it has dried out distorted
Dry it in place vs. remove it
Can often be dried: drywall wet by clean water (a clean supply-line leak), caught quickly, and not fully saturated — pros dry it with air movers and dehumidifiers while monitoring moisture, sometimes drilling small holes to ventilate the wall cavity.
Should be removed: drywall that's saturated and sagging, that's been wet long enough to lose structural integrity, or that was touched by gray or black water. Pros make a flood cut — removing the lower 12–24 inches of drywall — so the wall cavity, insulation, and framing can be dried and disinfected, then the section is replaced.
Why you can't just paint over it
The wall cavity behind the drywall holds the moisture you can't see, soaking insulation and the bottom of the framing. Painting or patching over wet drywall traps that moisture, and mold begins within 24–48 hours on the paper facing and the cavity behind it. Proper repair dries (or removes) to verified moisture targets first, then finishes. A drywall water-damage repair typically runs $300–$2,000+ depending on how much wall has to come out and be replaced.
Common questions
FAQ
Does wet drywall always need to be replaced?
No. Drywall wet by clean water and caught quickly can often be dried in place with air movers and dehumidifiers, sometimes with small ventilation holes drilled into the wall cavity. Drywall that's saturated and sagging, that's been wet a long time, or that was touched by contaminated water should be cut out and replaced rather than dried.
What is a flood cut?
A flood cut is when a restoration pro removes the lower portion of a wall — typically 12 to 24 inches of drywall above the water line — so the wall cavity, insulation, and framing behind it can be dried and disinfected. It's used when drywall is saturated or was contaminated by gray or black water, after which the removed section is replaced.
How do I know if drywall is water damaged?
Look for staining or discoloration, sagging or a soft/spongy feel when pressed, bubbling or peeling paint, a musty smell, or visible mold. Even a small surface stain can sit over a much wetter wall cavity, so the real test is a moisture meter — appearance alone understates how far the water spread.
Can mold grow behind drywall?
Yes, and it's common. The paper facing on drywall and the materials in the wall cavity — insulation, framing — hold moisture and feed mold within 24–48 hours. That's why painting or patching over wet drywall just hides a growing problem; the cavity has to be dried or the drywall removed first.
How much does drywall water damage repair cost?
A drywall water-damage repair typically runs $300–$2,000 or more, depending on how much wall must be removed and replaced, whether insulation is affected, and how far the water spread. Drying lightly wet drywall in place is at the low end; flood cuts with replacement and refinishing are at the high end.
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