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Here we illustrate and explain white or reddish brown bubbly surfaces on walls and white powdery or crystalline deposits left on walls, especially masonry walls, by moisture - efflorescence When investigating a building for a mold problem, you can save mold test costs by learning how to recognize Stuff that is Not Mold or is only Harmless Mold but may be mistaken for more serious contamination - save your money. Our photo at page top shows white fluffy crystals of mineral efflorescence near the bottom of a poured concrete foundation wall.

Because some clients have on occasion sent samples to our lab that really should not have been collected, much less looked-at, I provide this library of photographs of things that are "not mold" and don't need to be tested. These are substances that you can easily learn to recognize in buildings. Save your mold test money, and increase the accuracy of your mold contamination inspection or test for toxic or allergenic mold in buildings: review these items to learn recognize non-fungal materials or even possibly harmless cosmetic "black mold" often mistaken for "toxic fungal growth."

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How to Identify Efflorescence - Mineral Deposits (not mold) on Building Foundations and Masonry Walls

So many people have written, sent photos, called, and even sent samples of efflorescence or other things that are not mold that we offering these pictures and information about white and brown deposits in buildings. WARNING: Finding "not mold" material in a building does not mean that there is no mold or allergen problem. Even relatively harmless house dust collected on a surface and sent to our lab as a mold screening test can contain a surprising amount of problematic mold spores if the building has a mold problem.

Mineral efflorescence is a sign of leaks into a building - leaks that might indeed produce a mold problem. But don't mix up efflorescence itself with mold.Save your money, don't bother testing mineral efflorescence nor the other stains we describe at HARMLESS INDOOR PARTICLES.

What about white "growth" or stuff on walls, particularly masonry walls? You may be looking at efflorescence - which is not mold.

What is the White Fluffy Stuff on Building Walls

Efflorescence or "mineral salts" is a whitish crystalline or powdery deposit on damp masonry walls, especially foundation walls which are located below ground level. Our photo (at left) shows a less serious case of white deposits on a concrete block foundation wall - white wall deposits at the mortar joints.

This usually-white fluffy material is efflorescence, a crystalline mineral salt left behind as moisture comes through the wall and evaporates into the building interior. Efflorescence is not mold, though it is an indicator of wet conditions that could contribute to a mold problem somewhere in the building.

Efflorescence can vary in its chemical composition and therefore its color too. Reported since 1877, these salts leach out of brick, concrete, concrete block, stucco, and in some cases even stone. The salts that you see have been left deposited on the surface as water evaporates. Multiple salts (chlorides, nitrates, vanadium, chromium and molybdenum may be present in efflorescence material, depending on the masonry or stucco composition). Vanadium salts, common in clay or brick products from some areas such as Southwestern U.S., may produce green efflorescence on white or buff burned clay surfaces. Other efflorescence salts leave white or gray deposits.

Various descriptions of this efflorescence, often seen on concrete, brick, or concrete block chimneyswalls or foundations (either indoors or outside) are provided in the list just below. Readers should also see the brown wall, ceiling, or chimney deposits are discussed further at Efflorescence & brown deposits.

• white fibrous substance on concrete block foundation wall
• white or tan fluffy or brown deposit on brick, stone, or cinder block walls, foundations, or chimneys
• spiky or fibrous substance on a wall
• white cotton-like substance on the foundation wall or on a plaster wall
• light white or tan crystalline substance
• white mold that looks at first glance like "dryer fluff", polyfill or fiberglass.
• white powdery deposits on stucco exterior walls - stucco bloom
• white or brown or reddish brown bubbly or fuzzy stuff "growing" on a plaster, concrete, concrete block, cinder block, or brick wall or on a masonry chimney
• light green or gray fluffy material on a brick or clay surface
• Yellow or brown bubbly crust material seen on plaster and on painted masonry block surfaces

Let's look at typical white efflorescence more closely.

By shining our light along the surface of this concrete block foundation wall we made the mineral salt efflorescence fluffy stuff show up clearly and we show how it grows "out" from the wall surface. (Photo, above left)

Looking at this material with a low power magnifying glass you can easily see that it is hairy and even crystalline (photo above right).

Shown just above are two high-magnification microscopic photographs of efflorescence (mineral salts) which we took at 720x in our lab. This efflorescence sample was collected as "white powdery or cottony stuff on the foundation" by our client. It's easy to see that this is a mineral like substance, crystalline. It is not organic, not mold.

What Does it Mean to Find Efflorescence and Stains in a Building Interior?

What Causes Powdery White Blotches or Mottling in Paint on a Stucco Exterior Wall? Stucco Bloom.

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MOLD APPEARANCE - WHAT MOLD LOOKS LIKE
  Black Mold  Brown Mold
  Green Mold  Red Mold
  Yellow Mold  White Mold
  Invisible Mold
  Meruliporia Mold Photographs
  Recognize Cosmetic Mold
  Recognize Harmless Black Mold
  Stuff that is Mistaken for Mold
  White stuff that is not mold
MOLD APPEARANCE - STUFF THAT IS NOT MOLD
  HARMLESS INDOOR PARTICLES
    Basketball Mold Syndrome - BBMS
    Black stains from soot/thermal tracking
    Black stains from animals
    Black cosmetic mold
    Efflorescence & brown deposits
    Efflorescence & white or brown deposits
    House dust
    Pollen
    Sprayed foam insulation
    White stuff that is not mold
    Wood sap
ENVIRONMENTAL HAZARDS GUIDE
AIR POLLUTANTS, COMMON INDOOR
ALLERGEN TESTS for BUILDINGS
ALLERGY TESTS for PEOPLE
ALLERGY TEST ACCURACY
FLOODS IN BUILDINGS-priorities
MOLD INFORMATION CENTER
ACTION GUIDE - WHAT TO DO ABOUT INDOOR MOLD
CLEARANCE INSPECTIONS - MOLD CLEANUP
DO IT YOURSELF MOLD CLEANUP
ENERGY SAVINGS in BUILDINGS
ENERGY SAVINGS PRIORITIES
ENERGY SAVINGS RETROFIT CASE STUDY
ENERGY SAVINGS RETROFIT LEAK SEALING GUIDE
ENERGY SAVINGS RETROFIT OPTIONS
FIND MOLD in BUILDINGS, HOW TO
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INDOOR AIR QUALITY IMPROVEMENT GUIDE
INDOOR AIR QUALITY METHODS COMPARED
LEAD POISONING HAZARDS GUIDE
MOISTURE CONTROL in BUILDINGS
MOLD ACTION GUIDE - WHAT TO DO ABOUT MOLD
MOLD AGE - Old is the Mold?
MOLD APPEARANCE - WHAT MOLD LOOKS LIKE
MOLD APPEARANCE - STUFF THAT IS NOT MOLD
MOLD ATLAS & PARTICLES INDEX
MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD
MOLD REMEDIATION CLEARANCE INSPECTION
MOLD DETECTION & INSPECTION GUIDE
MOLD EXPERT, WHEN TO HIRE
MOLD INSPECTORS & MOLD TESTERS
MOLD PREVENTION GUIDE
MOLD RELATED ILLNESS GUIDE
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ODORS, Smells, Gases in Buildings-Diagnosis & Cure

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More Information on Building Diagnostic Inspections and Repairs

• How to Look For Mold, Hiring a Mold or IAQ Consultant, Getting a Remediation Plan
• Looking for Mold what mold is often found where in buildings - simple technical presentation
• Mold spores in the Home - a Photo ID Library for detection and identification of mold allergens 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 .
• Animal Allergens: Dog, Cat, and Other Animal Dander - Cleanup & Prevention Information for Asthmatics and regarding Indoor Air Quality.
• Mold in Fiberglass Insulation© 2005 comments about a field study in process, & more about health hazards from fiberglass insulation - DJF
• 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: the house eating fungus or "poria"
• Mold Central: indoor air quality investigation case histories, key links what to do about mold and indoor allergens - our Fear of Mold "Mycophobia" WebLog-Blog.
• Ozone Warnings - Use of Ozone as a "mold" remedy is ineffective and may be dangerous.Rot concerns in buildings-some building mold such as Meruliporia incrassata "Poria" risks serious rot and hidden structural damage
• Basketball Mold Syndrome - BBMS- sudden attention to old clues in buildings makes them seem brand new to some observers
• 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

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