Cover holes in the roof, windows, and doors with tarps or heavy polyethylene sheeting.
Secure the building against unauthorized entry.
Brace walls and shelves.
Standing water (and water-filled containers)
Debris from floor and/or wet floor coverings
Flood-soaked drywall and insulation.
Reduce temperature and humidity to prevent or arrest mold growth. Try to aim for 70º F and 45% relative humidity. Do not turn on heat!
If it’s warm outside and you have air conditioning, turn it to the coldest setting. If it’s cool with low humidity, get the air circulating with fans or natural ventilation.
Unplug voltage-sensitive equipment, such as computers, to protect against a possible surge when the power returns.
If you are in a historic building — especially one on the National Register of Historic Places — contact your state preservation agency and/or a structural engineer before doing cleanup.