Most mold jobs we see started as a water problem that looked handled. Someone mopped the floor, ran a fan, and the wall looked dry by the weekend. Three weeks later there was a musty smell and spots along the baseboard. Here is what is happening inside your walls, and what to do at each stage.
Hour 0–6: stop the water, protect the evidence
- Shut the supply valve (under the sink, behind the toilet, or the apartment’s main), or get the super to.
- Turn off power to wet areas if it is safe to do so.
- Photograph and video everything: the source, the water line, damaged items. Your insurer and landlord will want it.
- Move furniture, rugs and boxes off wet floors.
Hour 6–24: extraction and real drying
Surface water is the easy part. The problem is the water that soaked into drywall, insulation, subfloor and carpet pad. Household fans dry the surface and leave the inside wet. Professional drying uses commercial dehumidifiers, air movers and moisture meters to bring materials back to normal readings, and sometimes small holes at the bottom of walls to vent the cavity.
Hour 24–48: the window closes
The EPA’s guidance is that mold can start growing on damp materials within 24 to 48 hours. Paper-faced drywall, cardboard, carpet pad and dusty wood are ideal food. You won’t see anything yet. If materials aren’t drying by now, they probably need to come out.
Day 3–7: colonies
A musty smell, small spots at baseboards and inside cabinets. Water wicks upward in drywall, so growth often shows up higher than you expect. This is now a mold job, but still a small one if you act.
Week 1–3: hidden spread
Growth moves through cavities, behind cabinets and under flooring. Many jobs pass 10 square feet at this stage, which in New York means an independent licensed assessor and a licensed remediator are required (here’s why).
The takeaway
Drying costs a fraction of remediation. If you had water in the last 48 hours, call us at (347) 369-1545. We answer 24 hours a day. Or try the interactive mold clock on our homepage.