Drywall that's been wet for less than 48 hours can usually be saved with drying and a stain-blocking primer. Drywall that's been wet for more than 48 hours grows mold inside the gypsum core and has to be cut out and replaced. That single line — 48 hours — is the difference between a $300 cosmetic fix and a $5,000 remediation job. Here's exactly what to do in the first day after a leak in your LA home.
Hour 1–4: Stop the source and start drying
First priority is stopping the water. Shut off the local supply valve (under the sink, behind the toilet, at the laundry connection) or the main shutoff if you can't isolate the leak. Then start drying — open windows for cross-ventilation, run fans pointed at the wet area, and pull furniture and rugs away from the wet zone.
If the wet area is over a few square feet of drywall or includes the ceiling, call a water damage professional now — not in the morning. Same-day response keeps you on the right side of the 48-hour line.
Hour 4–24: Document and triage
Take photos of the source, the affected area, and any visible water staining. If you have homeowner's insurance, file the claim now — the insurance carrier will dispatch an adjuster within 24–48 hours and the documentation determines the claim payout.
Identify whether the affected drywall is salvageable (still attached, not soggy, not visibly stained beyond a few inches around the source) or compromised (sagging, soft to the touch, visibly bulging). Compromised drywall has to come out regardless of what your insurance says.
Hour 24–48: Cut out compromised drywall
Past the 24-hour mark, any visibly compromised drywall has to be cut out. The cut should extend at least 6 inches past the visible damage in every direction to make sure you remove all the wet material. Bag and dispose of the wet drywall — it's not coming back.
Treat the framing behind the cut with a mold inhibitor (Concrobium or equivalent) and let it dry fully before patching with new drywall. The patch can happen anytime from hour 48 onward — the urgency is on getting the wet material out, not on rushing the patch.
Past 48 hours: mold has already started
If wet drywall has been in place for more than 48 hours, mold colonies have already established in the gypsum core. You usually can't see them yet — they take 2–7 days to become visible — but they're there.
At that point, the drywall removal becomes mold remediation, with HEPA filtration, containment plastic, and PPE for the workers. The cost roughly triples vs. early-intervention drywall replacement, and the timeline extends to 5–10 days for the complete remediation-and-rebuild cycle.