Mold Action Guide after Flooding: Further Steps to Avoid Mold Damage After a Building Flood InspectAPedia® -
InspectAPedia offers impartial, unbiased advice without conflicts of interest.
We will block advertisements which we discover or readers inform us are associated with bad business practices,
false-advertising, or junk science. Our contact info is at
InspectAPedia.com/Contact.htm.
This chapter discusses further steps to be taken to prevent mold growth in a building after the
initial or high priority actions have been completed. Earlier we recommended our Flood Response Checklist which lists key actions you should take after building flooding to minimize mold damage, and includes some safety warnings. Our photograph shows a building after extensive demolition and cleaning of a basement and of first floor flooring. Walls and ceilings above the floor were left intact.
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.
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 that system as well. Extensive, technically detailed in-depth articles on other mold detection, testing, and prevention methods are organized at our Mold Information Center
FURTHER STEPS TO PREVENT MOLD Growth After Flooding in a Building
Once the immediate safety and de-watering and drying steps outlined above have been addressed, here are additional
steps to clean up, remove, or prevent mold growth in a building or in and on its contents.
Do Not Work in a Moldy Building without proper respiratory protection (HEPA-filter respirator) and other appropriate protection such as goggles,
protective clothing, gloves. People who are asthmatic, suffer from COPD, compromised immune systems, or who are elderly or infant should not be in a
moldy environment and certainly should not be performing the cleanup.
Eye Protection: do not put a moldy finger in your eye such as to scratch an itch. You risk serious infection or even blindness. Wash your hands
before eating our touching your eyes.
Skin Protection: do not expose skin to mold, sewage, or cleaning chemicals. Extra care should be taken to keep these materials out of
cuts, sensitive tissues, and the eyes.
Cleaning Furniture and other Hard-Surfaced Items After Flooding: hard-surfaced items from a flooded area, if they have not been actually damaged by the flood water itself,
can and should be cleaned using ordinary surface cleaning methods. Detergents or even soap and water are fine.
However if sewage backed into
the building during flooding, disinfection may be appropriate. For disinfection of surfaces use 1 cup of bleach to a gallon of water to clean
the item, then rinse it thoroughly so that it won't be damaged by the bleach. We ar gloves and dye protection whenever using bleach. Don't use
bleach and ammonia together - toxic chlorine gas will be given off.
Furniture that cannot be cleaned: thick upholstered furniture such as couches, and also cushions, pillows, if they were wet from flooding, cannot
be effectively cleaned. Don't waste money on steam cleaning or ozone "treatments" that don't work. If an upholstered chair is a valuable antique it may
be possible to have the old upholstery stripped, the frame cleaned, and new upholstery applied. Generally it's less costly to buy a new chair.
Cleaning Soft Goods like Clothes & Bedding after Flooding: curtains, blankets, bedding, clothing should be laundered or dry-cleaned.
Cleaning Books and Papers after Flooding: there are professional services that can clean or "de-mold" books and papers, typically using a
freeze-drying procedure. If you have materials that are going to require this process, protect them from further moisture and have them
collected for treatment as soon as possible. This is a very costly process that won't be reasonable for ordinary popular literature or non-critical
documents.
Heating and Air Conditioning Systems Treatment after Flooding: HVAC systems that move air through a building will need thorough and meticulous
inspection and possibly cleaning. If insulated ducts or insulation inside air handlers were flooded,
those materials need to be replaced as it is not possible to effectively clean the insulating material after flooding.
Additional inspection of the equipment electrical and fuel systems is needed to be sure that they are safe to operate.
It would be best if you DO NOT run the central air conditioning system or hot air heating system after flooding and before the building has been dried
and cleaned, as to do so risks contaminating its interior with mold or pathogens that will require extensive replacement.
On the other hand,
since we know that some people are going to insist on running the heat or air conditioning to try to assist the building drying process,
if conditions demand that you run this equipment temporarily, you may do so (after a safety inspection) with the assumption that you are causing
them to be contaminated, that they are blowing moldy air throughout the building, that they will need to be replaced, and that other building areas
served by the same duct system may need additional special cleaning.
If you must run a hot air heat or central air conditioning system to aid in drying out the building, you should include that system in the final cleaning, inspection, and testing steps to assure that any mold or other contaminants have been removed.
Hot water heating systems and electric heaters such as by baseboards or radiators as well as free-standing heaters and dehumidifiers and fans can be operated to help dry a building, as soon as the equipment has been inspected for safety. The safety inspection of the equipment is important because there
may be fire or shock hazards present if it's turned on without inspection.
Watch for Mold Growth and Mold Odors After Flood Cleanup: even taking the steps discussed above, if a building is not dried to a sufficient level, including the moisture level
of its ceiling and wall cavities, there is a real risk of the development of both visible and hidden mold.
If you see mold forming, additional steps to
remove moldy material and to further dry the building are needed. If you don't see mold developing, an inspection of the most-suspect building cavities for
hidden moisture or mold would be a smart step before you return the building to service. If there are persistent mold odors, further investigation
is in order to be sure you have not missed a hidden mold reservoir in the building.
Flooded Septic Systems: If your building is served by a private onsite septic system,
see Flood Response for Septic Systems what to do after a septic system has been exposed to flooding
Crawlspace Dryout Procedures: even after a flooded building has been cleaned and repaired, it is important to correct sources of future leaks and water entry if we want to avoid future water and mold damage. See CRAWL SPACE DRYOUT PROCEDURES for advice.
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website
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.