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Flooded home interior after hurricane or storm

Mold After Hurricanes and Floods

Time is critical. How to prevent mold after major water events and what to do if you miss the window.

The 24-48 Hour Rule

According to the EPA and FEMA, mold can begin growing on wet materials within 24-48 hours. This timeline is your most critical deadline after any flooding event. Every hour counts.

Hurricane and flood damage presents unique challenges: the scale is often massive, professional help may be unavailable due to demand, and floodwater is contaminated. Understanding these realities helps you prioritize effectively.

Immediate Response Steps

As soon as it is safe to enter your home, begin these steps. Do not wait for insurance adjusters if it means delaying critical drying.

Get free access to the full guide

7 immediate response steps after flooding

Safety Considerations

Required Safety Gear

  • N95 respirator (minimum) or P100 for mold
  • Waterproof gloves (rubber or nitrile)
  • Eye protection (goggles, not glasses)
  • Waterproof boots
  • Protective clothing (Tyvek suit ideal)

Safety Hazards

  • Electrical hazards from wet wiring
  • Structural damage and collapse risk
  • Gas leaks from damaged lines
  • Contaminated water and debris
  • Wildlife displaced by flooding

Have the electric utility disconnect power before entering a flooded structure. Do not turn on HVAC systems until they have been inspected - they can spread contaminants throughout the building.

Drying Strategies

Effective drying requires moving large volumes of air and removing humidity. Natural ventilation alone is rarely sufficient for significant flooding.

Equipment Needed

  • Industrial dehumidifiers: Residential units cannot handle flood-scale moisture. Rent commercial units rated at 100+ pints/day from equipment rental companies.
  • Air movers: High-velocity fans that create airflow across wet surfaces. Position every 10-15 feet along walls.
  • Air scrubbers: HEPA-filtered units that remove mold spores and particles from the air during and after drying.
  • Moisture meters: Essential for determining when materials are actually dry, not just surface-dry.

Drying Priorities

  • Walls: Water wicks up drywall. Remove baseboard trim and cut drywall 12-24 inches above the water line to expose wall cavities for drying.
  • Floors: Water penetrates under flooring. Remove carpet, pad, and sometimes hardwood to dry subfloors.
  • Insulation: Wet insulation will not dry in place. Remove and replace it.
  • HVAC systems: Have ducts professionally cleaned before running the system.

What Can Be Saved

Usually Salvageable

  • Hard, non-porous surfaces (glass, metal, plastic)
  • Solid wood furniture (if dried quickly)
  • Some flooring if dried within 48 hours
  • Appliances (with professional inspection)
  • HVAC equipment (with professional cleaning)

Usually Must Be Discarded

  • Carpet and pad exposed to floodwater
  • Upholstered furniture
  • Mattresses and bedding
  • Drywall exposed to contaminated water
  • Fiberglass insulation
  • Particleboard and MDF furniture

When in doubt about contaminated materials, discard them. The health risks and potential for hidden mold growth outweigh the replacement cost of most household items.

When to Call Professionals

After major flooding, professional restoration is usually necessary. DIY efforts are appropriate for minor flooding caught immediately.

  • Call professionals for: Flooding over 1-2 inches, any sewage involvement, water in walls or under floors, flooding lasting more than 24 hours, visible mold growth, or if you cannot dry within 48 hours.
  • DIY may be appropriate for: Small amounts of clean water, caught immediately, on hard surfaces, that can be dried within hours.

See our DIY vs Professional guide and contractor vetting guide for more details.

Insurance Considerations

Documentation Tips

  • Photograph and video all damage before cleanup begins
  • Keep a written log of all actions taken with dates and times
  • Save samples of damaged materials if possible
  • Get written estimates before authorizing work
  • Keep all receipts for cleanup supplies and equipment rental
  • Do not discard damaged items until the adjuster has seen them (or photographed)

File claims promptly - most policies have deadlines for reporting damage. See our insurance coverage guide for detailed information on what is typically covered.

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