Flood waters rising in Commonfort, Guanajuato,Mexico (C) Daniel Friedman Building Entry, Cleanup & Repair After a Flood or other Disaster
Procedures & Checklist Assess, Respond & Minimize Flooded Building Damage, Repair Advice, Mold Prevention

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Flood damage control procedures & checklist: if your building has been flooded, this article series provides an easy to understand guide for flood damage assessment, setting priorities of action, safety, and we provide special information about avoiding or minimizing mold damage.

This Building Flood Response Checklist sets priorities for what to do to protect your building from mold contamination after flooding from a burst pipe or from rising waters and area flooding. These are quick, simple steps to minimize mold damage in a flooded building.

This is the first in our series of building flood damage articles on steps to take to safely enter and repair homes or other buildings after area flooding due to hurricanes, rising floodwaters, burst pipes, or other water flooding.

We discuss safety for people entering flooded buildings, steps to preserve and protect the building from further damage after it has been flooded, how to get mechanical systems up and running again, evaluating for the need for structural repairs, demolition, and cleaning, and avoid mold in a flooded building. Our photograph above shows the authors examining flood conditions in Commonfort, Guanajuato, Mexico.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

FIRST PRIORITIES: What to Do After a Building Has Been Flooded

Rapid removal of soaked materials from a storm-flooded building (C) 2013 Daniel FriedmanHazards in and around flooded buildings include risk of structural collapse, risk of septic system collapse, trip and fall injury hazards, electrical shock hazards, fire and explosion hazards where natural gas or bottled gas are present, toxic sludge and materials containing waterborne bacteria, such as the E. coli and Enterococci bacteria, toxic mold growth indoors.

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Listed just below are quick, simple steps to minimize damage in a flooded building. These are the key actions you should take after building flooding to protect life and property and then to minimize flood damage, mold damage, and other safety hazards.

We discuss here: How to get electrical, heating, air conditioning, water piping, drain piping, septic systems working again after building floods. Mold prevention for flood-damaged buildings & homes & burst pipe response to minimize mold damage.

How to minimize mold damage after building leaks or flooding: "Anti mold" procedures that work and ones that don't work or are unsafe. How to clean up, repair & restore a building after flooding, wetting, or other disaster.

  1. If You Have Been Injured seek medical care at the nearest hospital or emergency facility. Floodwaters are often contaminated by sewage and there is risk of serious infection if wounds are not cleaned and treated.

    Emergency Assistance Telephone Numbers - U.S.A. or in CANADA: call 911 for most U.S. or Canadian communities or from a cell phone: call 112 

    Emergency assistance numbers for other countries are at FLOOD & DISASTER BUILDING DAMAGE REPAIR PROCEDURES - home
  2. Check on Neighbors to see if there are elderly or infant neighbors who are trapped, injured, or otherwise need assistance.

    Help a neighbor who may require special assistance--infants, elderly people, and people with disabilities.

    Elderly people and people with disabilities may require additional assistance.

    People who care for them or who have large families may need additional assistance in emergency situations.
  1. Check on the condition of and safety of your building, home or business to begin planning for damage control, flood or other damage cleanup, and building or business restoration

Warning: Do Not Enter a Flooded, Storm Damaged, or Earthquake or Hurricane Damaged Building if the Following Conditions or Hazards are Present:

Also see BUILDING ENTRY for DAMAGE ASSESSMENT for additional details.

Wet crawl space unsafe to enter (C) Daniel Friedman

This article series gives action & repair priorities if your building has been flooded, or damaged by another disaster in an easy to understand guide. We describe procedures for for flood damage assessment, setting priorities of action, safe entry procedures for damaged buildings, first steps to protect a building from further damage, how to dry out the building, how to return the utilities to operation, how to clean up a flooded or damaged basement or building, how to rebuild a damaged building, and how to prepare to minimize danger and damage hazards from future disasters.

We also provide special information about avoiding or minimizing mold damage in wet or flooded basements or buildings.

Flood or Disaster Damage Response Checklist for Building Damage Control

Photo of flood marks in a basement stairwell show water height (C) Daniel Friedman This document lists key actions you should take after building flooding to protect the building from further damage, to get things working again, and to minimize mold damage. We include safety warnings about entering and repairing buildings that have been flooded by storms, hurricanes, burst pipes, or other sources.

We also list after-flood anti-mold MOLD KILLING PROCEDURES that DO NOT WORK or are UNSAFE - to help you avoid unnecessary expense in dealing with mold after a building flood.

If your building is already moldy or if you suspect mold related illness in your building, we link to a step by step MOLD ACTION GUIDE dealing with toxic or allergenic indoor mold and other indoor contaminants: when and how to inspect or test for mold, when to hire an expert, how to clean up a moldy area, when and how to perform post-remediation mold testing.

If your septic system has been flooded we link to an article outlining WHAT TO DO ABOUT A FLOODED SEPTIC SYSTEM as well.

Extensive, technically detailed in-depth articles on other mold detection, testing, and prevention methods are organized at our MOLD INFORMATION CENTER

As soon as it is safe to do so, respond quickly to building leaks and floods in order to minimize damage to the building. While it may be impossible to safely enter or even inspect a building before waters have receded in areas of major flooding, hurricane or storm damage, as soon as possible the building should be inspected and the steps below begun.

  1. Before entering a building that has been flooded review BUILDING ENTRY for DAMAGE ASSESSMENT

    Watch out: An initial building survey is needed to assure that a building is safe to enter. Hazards in and around flooded buildings include risk of structural collapse, risk of septic system collapse, trip and fall injury hazards, electrical shock hazards, fire and explosion hazards where natural gas or bottled gas are present, loose or broken gas piping and gas leaks, toxic sludge and materials containing waterborne bacteria, such as the E. coli and Enterococci bacteria, toxic mold growth indoors.
  2. Stop the water entry or other ongoing damage. Obviously if flood waters are still rising or if a building has already become partly submerged you cannot easily stop water entry. But in other circumstances there are important steps you can take.

    For example: turn off the main water shutoff valve, nail down tarps to cover openings or leaks in storm-damaged roofing, direct surface runoff away from the building.
  3. Salvage or protect furnishings or possessions which have not yet gotten wet by moving them to dry areas.
  4. Remove standing water - this may mean calling the local fire department or other agencies who have special pumping equipment.
  5. Pump out flooded basements gradually: (about one-third of the water per day) to avoid structural damage. If the water is pumped completely in a short period of time, pressure from water-saturated soil on the outside could cause basement walls to collapse.
  6. Inspect the building more thoroughly for structural damage and safe entry.
    See FLOOD DAMAGE TO FOUNDATIONS. Temporary structural reinforcement may be necessary to prevent building collapse before entering some buildings for further inspection or for salvaging contents.
  7. Remove sludge, mud, and dirt that has accumulated in the building. Beware that often after an area flood such as during a storm or hurricane, public and private sewer backups have left various toxic materials in mud and sludge in and around buildings.

    Watch out for contaminated floodwaters or mud: water and mud in flooded buildings may be unsafe to enter due to chemical or bacterial contamination.
    See SEWAGE CONTAMINATION in BUILDINGS for discussion of how to test for and remove sewage contaminants from buildings.

    Unfortunately, significant mold growth in flooded buildings is likely unless the flood event is small (perhaps a burst pipe) and the damage is discovered and responded-to quickly. This means within 24-48 hours all of the critical steps need to be taken if you want to maximize the chance of avoiding a costly mold cleanup project. In freezing or very cold weather you may have a bit more time.
  8. Remove wet carpets, furniture, contents, and boxes of wet stored items. Store items to be salvaged from the flooded area outside or in a garage, not in upper floors of the flooded building. Otherwise you may accidentally carry mold or other contaminants to other building areas.
  9. Check the building structure and mechanical systems again for safety. Now that there is unobstructed access throughout a building, a more thorough and accurate visual inspection should be performed to look for evidence of building movement or broken, unsafe gas or electrical connections. Don't forget to check for damaged fuel storage tanks that may float or move during flooding, risking leaky oil or gas piping. Outdoor tanks that are buried may also be damaged by floating.

  10. Remove floor trim and lower portions of walls (such as drywall or paneling) (at least 12") and any wall insulation
    See FIBERGLASS INSULATION MOLD) , in rooms where the floors were wet or flooded. Porous materials like drywall or plaster which have been wet cannot effectively be cleaned and should be discarded.

  11. How Much Drywall to Cut Off After Flooding: If a floor was wet, even if water did not rise up the walls, remove no less than the bottom 12" of drywall as well as any floorboard trim. Water on a floor surface enters and wets the wall cavity and often causes a significant but hidden problem mold reservoir in the wall cavity.

    If mold is visible on a drywall covered wall, remove drywall to no less than 12" above any visible mold, including inspecting the wall cavity interior for visible mold. Because drywall comes in 4' widths, it is often economical to remove more drywall than the bare minimum, but to remove it in 4' or 2' increments from the floor as you move upwards.

    If removing moldy drywall along a wall surface where the walls were not wet from below, remove all visibly moldy drywall and in addition to removing drywall for another 12" above the last visible mold, also remove drywall horizontally for at least one more wall-stud bay.

    Inspect the back side drywall which has been removed and the cavity side of drywall which remains in place to be sure there is no visible mold there. (Some writers who advise leaving drywall unless the wall was flooded more than a few inches are mistaken. Ignore that advice as you'll just be asking for a later hidden mold colony in the wet wall cavity.)

  12. Remove upper portions of wall coverings (drywall or paneling) higher than 12" if these areas are wet, or if water entered the wall cavity from above.

  13. Remove ceilings that have been flooded from above, along with ceiling insulation

    See FIBERGLASS INSULATION MOLD), regardless of material such as plaster, drywall, or ceiling tiles. Suspended ceiling tiles which have been wet should also be discarded, and the remaining suspended ceiling tiles removed to permit inspection and drying as well as to inspect for evidence of water overhead.

  14. Remove wet materials (such as areas listed above) until you find a 12" or greater area of dry clean margin.

  15. If mold is already visible or suspected, use containment to avoid air movement from the damaged (moldy) area to other building areas.

    Containment (of moldy dust or demolition dust and debris) generally means negative air and poly plastic barriers.

    "Negative air" in a moldy or dusty work area: by use of fans blowing outdoors from the work area and plastic barriers at its entry keep the work area at negative air pressure with respect to the rest of the building. So dust in the work area does not tend to escape to other building areas.

    "Containment" means that plastic barriers are set up and other steps are taken to isolate a moldy or dusty work area from the rest of a building.

  16. Moldy Surface Cleaning: after rough demolition to remove wet and porous or visibly moldy materials and other items listed above, all remaining loose dirt and debris should be removed, and the remaining exposed surfaces such as wall studs and framing, masonry walls, floors, plywood sheathing, should be cleaned to remove all loose and surface debris.

    Stains in wood do not have to be removed provided there is no remaining surface mold or debris.

  17. Mold-contaminated Surface Disinfection: after area flooding it is safe practice to assume that septic or sewage contaminants accompanied the floodwaters, so disinfection of all building surfaces should be part of the cleaning process.

    However as emphasized above, do not permit the use of disinfectant or fungicidal sprays to serve as a substitute for removal of all debris and the physical cleaning of dirty or moldy surfaces.
    See MOLD CLEANUP with BLEACH for advice on how to mix bleach and water for surface cleaning.

    Surface cleaning and disinfection can proceed before the building has been fully dried, but this process cannot be reliably completed until the building has been dried. Cleaning debris while it is still wet has the advantage of less spreading of mold and pathogens by airborne dust. Cleaning workers should still be careful to avoid being splashed by dirty water or cleaning fluids.

  18. Building dryout using dehumidifiers, fans, heaters, to dry the exposed building areas and surfaces. We find that adding simple fans such as box fans or window fans set on floors indoors, and particularly, pointed at wet surfaces, will significantly speed the dryout process far beyond what an indoor dehumidifier can do if used alone. A comparison of the effectiveness of various building dryout procedures is

  19. Flooded Mechanical Systems: Electrical wiring, circuit breakers, fuses, air conditioners, heating boilers, furnaces, water heaters, appliances: inspect & repair flooded electrical equipment, heaters, water heaters.
    See CORROSION in ELECTRICAL PANELS for warnings about rust and corrosion in electrical equipment. Also, chimneys, flues, and ductwork may be unsafe to use if they have been flooded.

    See FLOODED HEATING EQUIPMENT REPAIR and FLOOD DAMAGED WATER HEATER REPAIR for safety advice and equipment inspection/repair procedures for heating equipment.

  20. Inspect upper building areas and dry or ventilate them. Depending on weather conditions ventilation may mean simply opening windows or use of fans to dry an area. Beware of blowing moist air into a cool building however as that will increase building moisture. A building attic over a flooded basement is likely to have an excessive moisture level so that area needs inspection and may need venting too.

  21. Disaster Aid for flood damage: check with your local and state officials, FEMA (Federal Emergency Management Association), and your local chapter of the American Red Cross to determine if special disaster aid has been made available for people in your area.

    Your local or state department of health may also know if assistance is available. The American Red Cross is often on the scene of floods and other disasters to provide emergency assistance such as clothing, food, and housing.


Continue reading at FLOOD DAMAGE CLEANUP & REPAIR GUIDE for detailed procedures for wet or flooding basement or building dryout & salvage & cleaning procedures.




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Flood Damaged Building Inspection, Repair, Damage Prevention

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