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This document gives advice on how to find and deal with mold in building basements and in basement insulation. This is a chapter of "How to Look for Mold" which describes how to find mold and test for mold in buildings, including how and where to collect mold samples using adhesive tape - an easy, inexpensive, low-tech but very effective mold testing method. This procedure helps identify the presence of or locate the probable sources of mold reservoirs in buildings, and helps decide which of these need more invasive, exhaustive inspection and testing. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links 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.

BASEMENT MOLD: finding the problem mold, allergens, or other particles in basements

• Leak History: Examine the basement for its evidence of recurrent leaks and water entry.
• Finished Basement Organic surfaces: Look carefully at organic surfaces such as wood, drywall, and carpets in a finished basement:
• Walls: drywall, especially low on walls, in wet corners, behind furniture, and in areas of leaks from above
• Ceilings: drywall, especially in areas of leaks from above, such as under baths or kitchens, and at the walls below roof eaves in cold climates where ice dam leaks may have sent water into wall cavities; look at hot water heating baseboard locations for bleeder vents or other leak points
• Ceilings: suspended ceilings: look on both sides of ceiling tiles for visible mold or leak stains; don't ignore possible mold in fiberglass-based ceiling tiles.
• Ceilings: inspect framing - the joists of floors above, and the exposed side of subflooring of the floor above. See our warning about mold growth on pine boards discussed at Attic inspections above.
• Floor: wall to wall carpeting is a very common mold and allergen reservoir. Don't ignore possible reservoirs of high levels of mite fecals and pet dander including pets from prior owners. Look for other signs of pet presence in the building such as scratches on doors and trim.
• Un-finished basement mold: Look carefully at organic surfaces in un-finished basements or behind or above finished surfaces
• Look for evidence of prior basement water entry - mold is more likely to have grown on wetter surfaces first in a basement. Stains on the floor or remnants of cardboard boxes that were there, wet, and then removed, are important clues.
• Inspect the exposed sides of all framing, joists, girders, posts
• Inspect the exposed under-side of subflooring of the floor overhead. See our warning about mold growth on pine boards discussed at Attic inspections above.
• Inspect the back side of stairs, especially the lower treads and risers
• Don't assume that because there is no visible mold on surfaces that there is not a problem mold reservoir in exposed insulation.
• Basement contents be sure to inspect furniture and stored materials in a basement where mold is suspected, such as cardboard boxes and their contents and the under-side of furniture and game tables. Often we find serious mold growth on the un-finished surfaces of wood objects, probably because the absence of a coating means that such surfaces take up more moisture than other sides of the same item.

Mold hidden in basement insulation or on basement contents

These three photos of fiberglass insulation, drywall, and a wall cavity which was cut open show the value of exploring building cavities where there may have been leaks from above, regardless of whether we're exploring in above-grade level living space or below-grade level basements. A roof leak had wet these wall cavities, leading us to test the insulation for mold and to inspect further for moldy drywall. The photos also illustrate that luckily not every building leak into every building cavity is going to cause visible mold growth on the hidden surfaces of drywall.

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ENVIRONMENTAL HAZARDS - INSPECT, TEST, REMEDY
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MOLD ACTION GUIDE - WHAT TO DO
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CRAWLSPACE MOLD
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HIDDEN MOLD, HOW TO FIND

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Mold and Allergen Recognition and Identification - Not All "Black Mold" is Harmful; Some Suspect Stuff is Not Mold

• How to Find and Test For Mold in Buildings - Looking for Mold - A 'how to' photo and text primer on finding and testing for mold in buildings
• Recognizing Mold: What mold looks like mold identification photos to help identify mold - choosing what to sample in buildings
• 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
• Stuff that is not mold but is often mistaken for it - things you may not want to test. Also, not all "black mold" is toxic - here are examples of harmless black mold.
• Mold Action Guide: an easy step by step outline of what to do about mold
• How to find mold without hiring anyone, for do-it-yourself'ers
• Associations: Sick House, Sick Building, SBS - Air Quality, Government, Private Associations and Information Resources
• Mold Test Kits - How to Collect and Send Your Own Mold Sample to our mold testing lab
• How to find a mold inspector or test consultant: Directory of IAQ,Sick Building, Mold Allergen Testing, Building Investigation Service Providers
• Meruliporia: the house eating fungus or "poria"
• Mold Investigation Tips for Home Inspectors how to find mold, where to look, what is likely to be important. Advice to building inspectors intending to inspect or test for toxic or problematic mold indoors, mold inspection methods, and mold test methods which are valid or invalid
• Mold Risk Levels in Buildings Based on Visual Inspection - simple visual clues help decide on action
• Mold in Fiberglass Insulation© 2005 comments about a field study in process, & more about health hazards from fiberglass insulation - DJF
• Frequently Asked Questions About Mold -- check this FAQ list & IAQ Site Map to see if you can find a quick answer to your mold concern
• When to hire a professional to inspect for toxic mold or other allergens
• Contact Us to arrange mold/IAQ building on site inspection and testing.

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