21.13 Mold after a flood

With humidity, mold appears quickly on anything that got wet. It can cause congestion, eye irritation, coughing, and asthma attacks. For the flood itself, see chapter 10.

1. Dry quickly. Remove or discard everything that got wet with floodwater and that you cannot clean and dry completely within 24 to 48 hours (CDC): carpets, mattresses, upholstered furniture, soaked drywall, insulation, cardboard.
2. Ventilate: open doors and windows; use fans if there is power and it is safe (never a generator indoors, chapter 9).
3. Protect yourself: N95 respirator, long gloves, unvented goggles, long sleeves, pants, and boots. People with asthma, allergies, lung disease, or weakened immune systems should not clean mold.
4. Clean hard surfaces with water and detergent. If you use bleach: no more than 1 cup of household bleach per 1 gallon of water (CDC), with windows open. Never mix bleach with ammonia or other cleaners.
5. Measure the area: the EPA says that if mold covers less than about 10 square feet (approx. 1 m²), you can clean it yourself; if it is larger, consult its guidance and consider a professional.
6. If you rent: photograph everything before cleaning, notify management in writing and your renters insurance. Walls, carpet, and insulation are the landlord's responsibility.