Water Damage 101: What to Do in the First 24 Hours

The first 24 to 48 hours after water damage decide almost everything about how the rest of the job goes. Mold can begin developing within 24 to 48 hours in the right conditions, which means how fast water is removed and how quickly the space is dried out is the single biggest factor in whether this stays a cleanup job or turns into a mold remediation job.

The first move is stopping the source, whether that means shutting off a water supply line or a main valve. After that, remove as much standing water as possible as fast as possible — every hour water sits is an hour it has to soak further into padding, subflooring, and drywall. Increasing airflow with fans and dehumidifiers immediately, even before a full assessment, helps limit how far the damage spreads while you sort out next steps.

Not all water damage is treated the same way, and the category matters. Clean water from a supply line is very different from greywater (washing machines, dishwashers) or blackwater (sewage, flooding), and the category determines what can be dried in place versus what needs to be removed and replaced entirely. Treating contaminated water like clean water — running carpet and pad through a normal dry cycle instead of removing it — is one of the most common and costly mistakes homeowners make.

Don't assume a carpet is fine because it feels dry on the surface. Padding underneath holds moisture far longer than the visible carpet does, and that trapped moisture is exactly what mold needs. If there's any question about how much water was involved or what category it falls into, the safest move is calling for an assessment immediately rather than waiting to see if it "dries out on its own."