Checklist for Building Entry & Repair After Flooding: Steps to Minimize Damage InspectAPedia® -
Checklist of actions to protect a building from damage after flooding - step by step guide to removing water and drying a building after water entry
Safety advice about entering flooded buildings
Priority of attention & repairs for buildings after flooding & water entry
Mold prevention for flood-damaged buildings & homes
Getting electrical, heating, air conditioning, water piping, drain piping, septic systems working again after building floods
Burst pipe response to minimize mold damage
Building flood response to minimize damage
Questions & answers about the priority of steps to take to enter, repair, & restore a building that has been flooded
This document provides a "Building Flood Response Checklist" - what to do to protect your building from mold 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.InspectAPedia offers impartial, unbiased advice without conflicts of interest.
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Our photograph above shows flood levels marked on a basement stairwell during flooding of the home. All of the mechanical systems were inundated.
If your building has been flooded, this website 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.
Our "Flood Response Checklist" provided in 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" 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.
FLOOD RESPONSE CHECLIST for Building Damage Control
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.
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.
Stop the water entry. Salvage or protect furnishings or possessions which have not yet gotten wet by moving them to dry areas.
Remove standing water - this may mean calling the local fire department or other agencies who have special pumping equipment.
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.
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.
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.
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.
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.
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.
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.)
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.
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.
Remove wet materials (such as areas listed above) until you find a 12" or greater area of dry clean margin.
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.
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.
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.
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 at WATER ENTRY in buildings .
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, chimeys, flues, and ductwork may be unsafe to use if they have been flooded. See FLOODED HEATING EQUIPMENT REPAIR and FLOODED WATER HEATER REPAIR for safety advice and equipment inspection/repair procedures for heating equipment.
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.
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.
Questions & Answers regarding this article
Questions & answers about entering, inspecting, & repairing buildings after hurricane, flood, or other storm damage
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Additional technical contributors & reference sources for this article are listed below.
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Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. (727) 595-4211 mark@BestTampaInspector.com 11/06
Hankey and Brown home inspectors, Eden Prairie, MN, technical review by Roger Hankey, prior chairman, Standards Committee, American Society of Home Inspectors - ASHI. 952 829-0044 - hankeyandbrown.com 11/06
Arlene Puentes, a licensed home inspector, educator, and building failures researcher in Kingston, NY. 11/29/06
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
Kansas State University, department of plant pathology, extension plant pathology web page on wheat rust fungus: see http://www.oznet.ksu.edu/path-ext/factSheets/Wheat/Wheat%20Leaf%20Rust.asp
"A Brief Guide to Mold, Moisture, and Your Home",
U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
Allergen Tests in buildings advice about how to test, what to look for, in evaluating the level of dog, cat, or other animal allergens in a building
"IgG Food Allergy Testing by ELISA/EIA, What do they really tell us?" Sheryl B. Miller, MT (ASCP), PhD, Clinical Laboratory Director, Bastyr University Natural Health Clinic - ELISA testing accuracy: Here is an example of Miller's critique of ELISA
http://www.betterhealthusa.com/public/282.cfm - Townsend Letter for Doctors and Patients
The critique included in that article raises compelling questions about IgG testing assays, which prompts our interest in actually screening for the presence of high levels of particles that could carry allergens - dog dander or cat dander in the case at hand.
http://www.tldp.com/issue/174/IgG%20Food%20Allergy.html contains similar criticism in another venue but interestingly by the same author, Sheryl Miller. Sheryl Miller, MT (ASCP), PhD, is an Immunologist and Associate Professor of Basic and Medical Sciences at Bastyr University in Bothell, Washington. She is also the Laboratory Director of the Bastyr Natural Health Clinic Laboratory.
Allergens: Testing for the level of exposure to animal allergens is discussed at http://www.animalhealthchannel.com/animalallergy/diagnosis.shtml (lab animal exposure study is interesting because it involves a higher exposure level in some cases
Allergens: WebMD discusses allergy tests for humans at webmd.com/allergies/allergy-tests
Animal Allergens: Dog, Cat, and Other Animal Dander - Cleanup & Prevention Information for Asthmatics and regarding Indoor Air Quality.
Recognizing Allergens: What various indoor allergens look like - identification photos to help identify pollen, dust mites, animal dander, toxic or allergenic mold - Common Mold and other Allergens, Irritants, Remedies & Advice
Rodent control issues, including dander, fecal, and urine contamination of buildings and Building insulation are discussed at our
Associations: Sick House, Sick Building, SBS - Air Quality, Government, Private Associations and Information Resources
Atlas of Clinical Fungi, 2nd Ed., GS deHoog, J Guarro, J Gene, & MJ Figueras, Centraalbureau voor Schimmelcultures, Universitat Rovira I Virgili, 2000, ISBN 90-70351-43-9 (you can buy this book at Amazon)
Atlas of Indoor Mold, Online Clinical Mold Atlas, Toxins, Pathogens, Allergens and Other Indoor Particles - Medical Health Effects of Mold (separate online document)
Black Mold that is Harmless Photos of recognizable, usually harmless black mold on wood, bluestain, ceratocystis, ophistoma
Building Floods: quick steps after a building flood or plumbing leak can prevent costly mold contamination
Classes of Mold: what types of cosmetic, allergenic, or toxic mold are a problem? Can mold be cleaned-up successfully?
"A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
"Disease Prevention Program for Certain Vegetable Crops," David B. Langston, Jr., Extension Plant Pathologist - Vegetables, University of Georgia (PDF document) original source: www.reeis.usda.gov/web/crisprojectpages/209797.html
"Disease Prevention in Home Vegetable Gardens,"
Patricia Donald,
Department of Plant Microbiology and Pathology,
Lewis Jett
Department of Horticulture, University of Missouri Extension - extension.missouri.edu/publications/DisplayPub.aspx?P=G6202
Fifth Kingdom, Bryce Kendrick, ISBN13: 9781585100224, is available from the InspectAPedia online bookstore - we recommend the CD-ROM version of this book. This 3rd/edition is a compact but comprehensive encyclopedia of all things mycological. Every aspect of the fungi, from aflatoxin to zppspores, with an accessible blend of verve and wit. The 24 chapters are filled with up-to-date information of classification, yeast, lichens, spore dispersal, allergies, ecology, genetics, plant pathology, predatory fungi, biological control, mutualistic symbioses with animals and plants, fungi as food, food spoilage and mycotoxins.
OTHER IAQ ISSUES: How To Find and Address Other Indoor Air or Indoor Environment Contaminants Besides Mold
Mold or allergens may not be the only or even the main indoor environmental contaminant. Don't let media attention to mold
cause so much enviro-scare fear that other, possibly more urgent hazards go un-addressed.
Ozone Warnings - Use of Ozone as a "mold"
remedy is ineffective and may be dangerous.
Pet control - if you can't say goodbye to your bird, cat, dog, guinea pig, hamster, tropical fish, then limit the
areas they occupy and limit the airflow from that area to sleeping or other areas of the building, use allergenic
bedding, eliminate wall-to-wall carpeting, improve housecleaning including use of a HEPA-rated vacuum cleaner. For more details
see our article Dog, Cat, and Other Animal Dander - Information for Asthmatics and Indoor Air Quality
Rodents, Mice, Squirrel Control - I find high levels of mouse and rodent dander, fecal dust, and urine-contaminated dust in some buildings,
and high levels of these materials in building insulation in those locations. If you have a mouse problem, particularly if mice and their waste (fecals or urine) are contaminating
the building HVAC or building insulation, may need both steps to clean up or remove infected materials and steps to stop an ongoing
rodent problem. If squirrels are a problem, the cleanup needs to include closing off entry openings into the building. Get some
help from a licensed pest control expert.
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