Mineral Efflorescence - Water Deposits, Salt Deposits, Brown & White Bubbly or Fluffy Crystalline Deposits - Diagnostic Photographs
InspectAPedia^® -

How to identify white stains, white fluffy material, white crystalline material on building walls & in basements and crawl spaces -mineral efflorescence is not mold.
How to diagnose powdery white blotches on a painted stucco exterior wall - Stucco Bloom
How to identify signs of moisture or water entry in buildings & signs of high moisture
Although efflorescence and mineral salts left behind by water are not mold they mean that mold-friendly conditions are present in the building
How old is the efflorescence and how long does it take for efflorescence to form? Efflorescence = efflorescence = efforfescense = efflorescence if you're spelling efflorescence wrong.
Questions & answers about white & brown building stains & deposits: efflorescence causes, significance, cures

White stains & deposits in buildings - may not be mold: what is efflorescence, what causes this white powdery growth or stain on building surfaces, and what does efflorescence mean as an indicator of moisture problems in buildings? Here we illustrate and explain white or sometimes reddish brown bubbly surfaces on walls and white powdery or crystalline deposits left on walls, especially masonry walls, by moisture - efflorescence.

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

When investigating a building for a leak, water entry, or 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. Brown and other colors of efflorescence deposits are shown at Efflorescence & brown deposits.

Our photo at left shows white efflorescence on the outside of a masonry chimney - discussed at White/Light Stains on Chimneys.

To clean off efflorescence, see our advice at What steps should I do to remove efflorescence from my building?. Readers who need to cure or prevent efflorescence, mold or "mildew" in buildings should see STAIN DIAGNOSIS on BUILDING INTERIORS, and MOISTURE CONTROL in buildings as well as HUMIDITY LEVEL TARGET also VENTILATION in buildings and WATER ENTRY in buildings.

Because some clients have on occasion sent samples to our lab that really should not have been collected, much less looked-at, we 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."

Effloresence mineral salt damp basement - Daniel Friedman 04-11-01

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.

Effloresence explained (C) Carson Dunlop Assoc

Carson Dunlop Associates' sketch (left) illustrates how efflorescence is deposited on building interior walls.

Multiple kinds of mineral 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 chimneys, walls 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

Effloresence closeup (C) Daniel Friedman

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).

Here is a photo of efflorescence (mineral salt) which we collected from the wall (above) using clear adhesive tape, so you can see the appearance of mineral salts left behind by water leaking through a masonry block wall.

We used a low power stereoscopic microscope to see what this stuff looked like but it was not very informative so we decided to take a closer look using our Polam high-power light microscope.

Here's the same tape sample of efflorescence under the high power microscope at about 100x.

You can see the crystalline structure of this substance in the long, translucent fibers. The black stuff is dirt from the wall surface.

Photograph of Effloresence on a Foundation wall © D Friedman 2008

Polarized light photograph of effloresence on a basement foundation wall © 2010 D Friedman

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.

Below are two more microphotographs of larger particles of mineral efflorescence taken in our lab at 480x (4/19/10). The right-hand image of the same particle shown at left uses cross-polarized light to demonstrate a mineral quality of the substance. On the sample tape the material appeared as a white and light lemon-yellow powdery substance.

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

MOLD & HEALTH WARNING: although efflorescence is not mold, it often indicates wet conditions that cause problem mold growth elsewhere in the same building. You'll need to identify the sources of moisture or leaks and correct them, and depending on other building air quality complaints or health concerns it may be appropriate to inspect and screen the building for problem mold or other moisture or water-related problems.

Where you find efflorescence in a building indoors, you should look for problem mold, allergens, bacteria. Look on organic surfaces - wood, paper, painted surfaces, insulation, fabrics, carpets, carpet padding, or in settled dust and debris.

In our photograph (left) the client is pointing out that water has been entering this basement from the very top of the foundation wall (due to outside roof spillage and bad drainage) - we did not agree with the contractor who told her this was "rising damp" due to wet soils.

How Old is the Efflorescence on a Building Surface & How Quickly Can Efflorescence Form?

Question or Age of Efflorescence on a Building

I would like to know the typical length of time that is necessary for a crystal-like efflorescence thing in my photos to develop. I was told that it would take "years". I believe mine developed over a period of 3-6 months. Is that possible? Thank you again.

Background: I have spent nearly $4000 on a water intrusion situation that is no where near resolved. We live in the Dallas, TX metro area. Our property experienced a 3+ month long recurring city water main break beginning in Oct 2009.

During this time period I discovered mold growing all over household items and furniture. It was not until Feb. 1, 2010 that I looked in crawl space and discovered standing water on top of plastic vapor barrier. For the last three months I have consulted dozens of local experts, including engineers, foundation and drainage companies. My home owners policy rejected my claim as it was a city line that broke. The city insurance rejected my claim saying they have "governmental immunity".

Prior to the flooding event I have lived in this home for 13 years with no problems. It has only been since the city water main break that we have had these issues. The final repair to city line was completed in January. My crawls space has been so wet that no one will venture under there.

In April we installed an open face surface drain to catch roof and surface water to see if that would help. Even after this modification it now seems that with each subsequent rain event that more water is entering the crawl space. we are at my wits end and have about run out of funds to address this problem.

I have been in contact with my city council person and my goal is to try and get the city to help remediate this mess. I have a difficult task of "proving" to them that they are responsible for this. ... I believe the city water leak put so much pressure against my perimeter concrete foundation that what we are looking at is a form of efflorescence, rather than a fungus suggested by a city worker. Notice the weird staining patterns behind the crystal thing. Would you be willing to comment about what you see in these photographs? - S.M.

Reply

OPINION - is it Efflorescence?: It is pretty easy to distinguish between mold and efflorescence, as photos on this page show. Efflorescence is a crystalline mineral salt. It looks crystalline under magnification, even low magnification. Mold is an organic growth and certainly does not look like crystals. See MOLD APPEARANCE - WHAT MOLD LOOKS LIKE. If necessary, a simple tape lift of surface material can let a laboratory confirm whether or not the substance you are seeing is mold or efflorescence

Watch out: the same conditions that produced efflorescence mean that there has been high moisture or even water in the building, just as you described above. So where efflorescence is found in a building, mold contamination may be present in the same or even other building areas (moisture travels upwards through a building from a wet basement or crawl area.) In addition to checking for mold contamination, it is very important to dry out the crawl space and keep it dry. See our guidance on crawl spaces at CRAWL SPACES.

OPINION - how old is the efflorescence?: Age of efflorescence: we don't agree that "years" are necessary before efflorescence becomes visible on a building surface. The photograph just above may have been of an old condition, but as we have found such stains on homes just a year or two old, clearly the rate of formation of mineral salt efflorescence on a surface depends on local conditions and a number of more technical variables. The lack of extensive rust or stains on other crawl surfaces argues that the water intrusion may be more recent than the age of the home.

Basically to find efflorescence on a building surface we need moisture wicking through masonry, then evaporating off of the surface to form effloresence.The rate of deposition of crystals probably depends on the level of soluble salts in the masonry through which water is moving, the level of other dissolved minerals in the water, other water chemistry factors, the extent and frequency of water source. All of that technical depth is beyond our expertise. But in general, we would not be surprised to see white stains on a masonry block wall in 6-months to a year if conditions are right.

Some moisture stains and efflorescence do have an older look, a sort of crust, that seems to form after a longer time of wet and dry cycling.

It's an interesting question - let's hear from some masonry chemists. CONTACT us if you have more information on efflorescence age.

Watch out: while we are sure that efflorescence can form on a masonry surface within months under the right conditions, don't mistake "old" efflorescence for "new". Some light efflorescence deposits can be quite old on a building wall.

But if you are sure that efflorescence satins on a surface did not have white efflorescence stains, yellow efflorescence stains, brown stains (as in our photo at left), tan efflorescence or stains at a particular time, and the material appeared more recently by your own observation, we agree that it is certainly accurate and reasonable that the correct assessment is that the efflorescence is new.

You may be able to sort out the age of efflorescence using some of the same thinking we use to sort out the age of mold: look for other evidence of the history of leaks or water entry such as other stains, or rot. See MOLD AGE - Old is the Mold?.

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

Our photo (left) shows white blooming efflorescence and mottling appearing on painted stucco after less than a year of application of paint onto a new stucco exterior wall in the Southwestern U.S. See PAINT on STUCCO, FAILURES for details of paint failure diagnosis on stucco surfaces. We also discuss efflorescence as a type of paint problem at PAINT FAILURE DICTIONARY.

Painting over cracks where moisture has not fully evaporated or painting over a new stucco wall too soon and where the wall pH or alkalinity remains too high (over 11) can lead to both cosmetic problems as well as early wear or failure of the painted coating.

The application and curing procedure used for stucco, in turn affect the wall pH - it needs to be tested by the painter before the paint job begins.

Frequently Asked Questions (FAQs) about white & brown building stains & deposits: efflorescence causes, significance, cures

Question: Bubbling wall surface, brown & white deposits, dusty: is this mold or efflorescence?

I was looking at your very good website because I found, when I was cleaning, some brown stains and painting bubbles/peel in the closet wall.

The bathroom is on the opposite side of that wall and you see on the photo that there are some piping there which I think are connected to the shower. When I scraped some of these bubbles I got some white powder like dust, however the concrete seemed to be dry with touch.

There are some bubbles and peeling in the bathroom (same wall) but concrete there seemed to be also dry with touch.

Do you think I have mold on my hand or just some stains which I can fix by scraping of the peeling painting and repaint?

Ps. The air humidity is normally 30-40% often nearer 30% mark.

Sincerely, S. - Iceland

Reply: Expect efflorescence on leaky masonry surfaces; expect mold on organic surfaces (wood, drywall, paper) when those surfaces have been wet

A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem such as the moisture source that has caused the wall damage in your photograph. And certainly we can't absolutely identify building materials by email and photos, but that said, your photo looks to me like mineral efflorescence and bubbling paint on a masonry wall.

So if the wall in your photo is solid masonry such as painted solid concrete, concrete block or stucco or cement over a masonry wall, we're most likely looking at mineral salts left behind as moisture evaporates from the wall surface.

Why Effloresence Forms Paint Bubbles on a Painted Concrete Wall

The lifting power of the mineral crystals of efflorescence that form during moisture evaporation is quite strong, easily pushing paint off of the painted concrete wall to form the bubbly surface in your photo.

Take a closer look at that whitish or light yellow "powdery" material on the wall, using a magnifying glass and I expect you'll see that the material is crystalline - mineral efflorescence - not organic mold structures.

See the text in our Efflorescence article just above for more illustrations of mineral efflorescence Typically the problem comes from moisture leaking through masonry walls. I would not assume there is no mold in other areas of the the building however, particularly if you've had other leaks that wet more mold-friendly materials that support fungal growth such as wood, drywall, paper, carpeting.

More photos of brown and other colored deposits on masonry walls can be seen at Efflorescence & brown deposits.

Can Mold Even Grow on Masonry?

Most mold genera/species require organic material for food. In buildings that means mold-friendly materials include wood, drywall, paper, carpeting, paint, some plastics, cloth, and similar stuff. But indeed, we can on occasion see mold on a masonry surface, usually under one or both of the following conditions:

The masonry wall is painted - the mold is growing really on the paint, not the masonry
The masonry wall may be unpainted but has a coating of dust and debris that includes organic particles - we find this condition, for example, in a damp basement where dogs or other animals are kept
On some buildings, usually outdoors, there are even some mold genera/species that will form directly on the masonry surface, though more often we find that stains are actually algae, not mold.

Relation of indoor humidity level and efflorescence formation on masonry walls

Finally, regarding your observation that "The air humidity is normally 30-40% often nearer 30% mark." - that's a pretty low indoor humidity level. But I'll bet that the location where you are measuring the relative humidity is not the surface of that bubbly stained wall, right? Typically when I see a masonry wall that looks like the one in your photo I find a leak or water source outside the wall, one that is sending moisture through the wall. The lower indoor humidity actually speeds the formation of efflorescent salts because the relatively dry indoor air helps speed moisture evaporation from the wall surface - leaving those salt crystals behind on the wall.

My advice: see if you can find and fix the moisture source that is causing the wall damage from effloresence in your photo.

Question: Is this white fluffy stuff efflorescence? and If So how should I clean and Paint it?

JO said: I'm not sure if I have Efflorescence or not! There is a small wall inside my Kitchen that has flaking off paint and the paint that is still attached looks like chalk dust. Is this just damp? If so, what paint shall i use? Thanks for any help and advice!

Reply: Cures for Efflorescence or "white mineral salt stains and deposits"

Jo, I can't tell from your description if you have efflorescence or just peeling paint. Take a look at the photos on the page above where we show just what efflorescence looks like.

The "cure" for efflorescence involves:

1. Find and fix the leak or moisture source that is causing the problem

2. Vacuum and clean off the surface thoroughly

3. You can re-paint using a moisture tolerant paint (latex) or on foundations a moisture resistant paint such as those made by Thoro (TM) [Thoroseal].

But if you don't find and fix the moisture source, peeling or chalking or efflorescence are likely to recur. The lifting power of mineral salts forming on a masonry surface is quite strong and has no trouble pushing off paint.

Question: How do I stop Efflorescence from Growing or Forming

Lorraine said: hi Jim, did you find a way to stop the effloresences? from Lorraine

Jim said: I have the same fibrous growth in certain places on my basement concrete floor. I at first thought it was mold and used bleach to wash the area, but to my surprise it was back in less then a week and just as tall, 1/4-3/8" high. After some research online today I see it is the salts or effloresences leaching up. Under the right conditions it only needs a week or less to become visible and be 1/4" or more high.

Reply: Find and fix the moisture source or efflorescence will continue to appear

Lorraine, cleaning off the efflorescence is easy, using just about any household cleaner, even a damp sponge or vacuuming and washing the surface, then letting it dry. You can also try applying a sealer suitable for the particular surface material. But if we don't find and fix the moisture source the efflorescence will return.

Question: I think I have Efflorescence growing out of a bathroom floor - but it's growing really fast. Will it stop once the concrete has dried?

Jenn in So.Cal. said: I have this, at least I think it is, growing out of my bathroom floor. But the stuff I have grew/grows REALLY FAST. We repaired a plumbing leak in said bathroom this past Saturday. After which, we decided to remove the carpet was not only completely soaked, but old and worn out. (frankly I've never quite understood the idea of putting carpet in a bathroom. Gross!!)

Anyway- This left us with the bare concrete slab as a floor. Before midnight that night, 50% of this bathroom "floor" was covered with fluffy white "waves" of fine crystalline growth around 1/2 - thick. I vacuumed it up yesterday afternoon, and this morning it was back to where it was the night before!

Before I found this great site, and reading thru the info you provide here, we worried it could be some mutant miracle grow mold, waiting to attack my asthmatic lungs or my husbands allergy prone sinuses. Or maybe just a result of many years of "love my carpet" type powders and/or carpet shampoo, or something else entirely. From what I've read so far, I think I've got mineral effloressence. If that is the case, will it stop once the concrete is dried out? I imagine we'll have to give it some time before laying tile. Which is fine, there's no rush. Are there any "prep" recommendations?? I thank you for your time. And for your wonderful and informative site. Very helpful indeed. I've already told a few friends about it!

Reply:

Jenn: Yes if you can dry out the area AND if you do not have an outside water source sending moisture up through the slab it may dry out enough that the efflorescence formation will stop or at least mostly stop; Efflorescence is a crystalline formation of mineral salts that can indeed appear rapidly on masonry surfaces when there is plenty of moisture present.

Question: I see white blotches where carpet squares were removed from the concrete floor. Is this a worry?

Half of my basement was completely finished 10 years ago and I have carpet squares with a rubberized backing over the concrete floor. I recently lifted up several squares and noticed small white blotches on many areas of the concrete floor. The carpet square backings are intact. Are the white blotches anything to worry about? They're not raised blotches -- they're pretty flush with the concrete. - Jim B.

Reply:

Jim B: I can't know from so little info if the white blotches on the concrete floor under carpet squares are a real worry or not, but they do indeed sound like an indication of moisture in the basement; SInce the rubber-backed carpet squares are pretty moisture resistant, moisture may have been trapped on the concrete floor below, forming mineral efflorescence If you remove the carpet squares and clean the floor and keep the humidity in the area low (target 40%) and if there is not an outside moisture source, you should be OK.

Comment:

This efflorescence can take as little as days to form. I was at work scraping paint chips from an outside wall. Came back 4 days later and noticed this stuff all over the wall. So it does not take years by any means. - Joe

Question: After a basement flooding we see this white efflorescence stuff - could it be from remaining floodwaters?

in february we had a very very bad flood in our basement due to a broken water line, we cleared out the basement and removed the carpet. within a few days and major rain we noticed puddles forming by the exterior wall. we had the old clay weeping tile removed and replaced and window wells installed. since then we have noticed efflorescence forming on the floor in front of that same exterior wall. there is no dampness on the floor, (that i can feel) i have cleaned (vacuumed) this efflorescence and it returns within days. now that it has been dryer because of the summer weather the formation has slowed down. I would like to re-carpet the floor down there however i have to figure out what steps to take first to water proof this area. I have read many articles on the net but there is contradicting information. could the efflorescence be the remaining water from the flood and the pre-weeping tile? thanks - Teri.

Reply:

Teri, I've worked with efflorescence and building moisture and water entry problems since the 1970's. In all cases in my own experience as well as in what I've studied, you need the combination of moisture and a mineral-containing material like masonry, concrete, stone, cement, mortar, etc. to produce mineral-granule efflorescence Moisture wicks up through the masonry material from a water source, evaporates, and leaves dissolved salts behind on the material surface.

Efflorescence will pretty much stop appearing if you can dry out the area. Now I'd agree that following a cleanup it's possible for there to be some remaining moisture, say below a floor slab, or else an ongoing water problem that has not been cured. But if there were NO moisture, you'd not see efflorescence That's a sound conclusion.

Comment:

thanks for your response dan, we just had a major rain and there is no evidence of water anywhere. we do have a sump pump in the basement as well, which does its job well. we also run a dehumidifier in the area. should i try to seal the floor with a concrete sealer before carpeting? and if so which one would you recommend? - Teri

Reply: A masonry sealer can slow down efflorescence formation

Teri if the floor surface is clean and dry a masonry sealer can help break the evaporation path that by capillary action pulls more moisture through masonry. There are two different approaches: silicone masonry treatments that mostly resist water entry into the masonry, and coatings such as portland cement based masonry sealer paints, or more extreme, epoxy paints.

No paint will withstand moisture pressure from beneath the paint surface for long, so paints don't absolutely stop moisture passage long term but they interrupt the evaporation-pull process.

But the masonry sealer paints I know about are not suitable for floors; you'd use an epoxy or other floor paint intended for concrete surfaces.

Frankly, all that said, if you've dried out the water source painting should not be necessary, but finally, in a basement, I would never put down wall to wall carpeting in any event. You're asking for an intermediate or long term mold and allergen problem. I prefer an epoxy painted finish floor, ceramic tile, or vinyl tile glued to the concrete floor surface. Over that if you want a few cleanable area rugs, that's fine. - Dan

Question: I bleached the efflorescence spots but it returned, Why?

I cleaned what seemed to be mineral efflorescence with bleach diluted in water, and the next day it appeared again in the same spot. Is it mineral efflorescence, then? Thanks. - Elena

Reply: Efflorescence is not a biological product; it reappears due to moisture or water leaks. Bleach won't "kill" mineral deposits nor stop their reformation

Elena, because mineral efflorescence is a mineral, not a biological product, cleaning with bleach is only of cosmetic use and may not really be necessary at all. You could use any household cleaner. But unless the moisture source is also found and stopped, the efflorescence will indeed return.

Just how fast efflorescence salts reappear (in your case the next day) depends on building variables such as the amount of water outside the wall, the rate of moisture movement through the wall, the mineral content of water when it reaches the inner wall surface, and the evaporation rate from that surface (in turn a function of indoor humidity). In other words, bleach won't stop efflorescence formation on a wall surface. - Dan

Question: Is the white fluffy stuff that appeared after Hurricane Irene efflorescence or mold?

After the water from hurricane Irene dried out of our basement, we have noticed some white fuzzy stuff that I believe is efflorescence. The floor where it is coming in is slightly pocked, as though the white stuff grew out of the floor. Does this sound like mold? - Slothburger

Reply: How to distinguish efflorescence from mold

Slothburger, there is white stuff that is efflorescence (crystalline mineral salts), and there is white stuff that is mold. If the white stuff looks crystalline under a magnifying glass, and if it's being produced on a masonry surface, it's probably efflorescence

At MOLD APPEARANCE - WHAT MOLD LOOKS LIKE you'll see a link for White Mold - take a look and you'll see the difference between what mold looks like and what efflorescence (this page above) looks like. - Dan

Question: We have efflorescence in a wall in our apartment. It will grow back within two or three days

We have efflorescence in a wall in our apartment. It will grow back within two or three days, even after being treated with a water-stop kind of "paint" -- we had a painter treat our wall and then he painted it, and after just a few days, the paint had already bubbled up again. It's going to be my one-year-old son's bedroom, and I really don't want bubbly paint in there... I don't know what to do to fix this... If it was just a basement, I wouldn't care. The wall appears to be dry. The plumber checked all the pipes. WHAT CAN WE DO???

I just commented about our apartment, and then read some more comments below, and it sounds like we have to find the source of moisture, but our plumber insisted that there was no leaking from the pipes in the wall (after he chipped away all the concrete around the pipes.) So I wonder how we can find the source of moisture in a concrete wall? -Teri

Reply:

Indeed Teri, if there is no plumbing leak in a supply nor drain pipe (be double sure) then we have to look for other water sources such as roof spillage, roof leaks down the wall, or other outdoor water leak sources wetting that wall area.

Question: what is the best way to remove the white mineral salts stains on outside rendered and painted walls

Thanks - Marg

Reply: Look at our stucco paint failure information, clean, seal, and repaint + find and fix the leak

Marg you might search InspectAPedia for stucco paint failures for examples of white salts showing up in exterior paint on a masonry type wall surface.

Ordinary cleaning with any household cleaner, followed by thorough drying, followed by application of a sealer to reduce future moisture up-take, then re-painting will clean up the issue.

But you want to perform some diagnostic detective work to be sure you understand where the moisture came from in the first place; if, for example, moisture is entering a wall from a building leak, the efflorescence (white mineral stains and salts) will return unless the leak is fixed.

Question: White crystallized material in the shower drain - could this be effloresence and is it a health risk to someone suffering from pseudomonas-related illness

My husband remodeled our bathroom. It has plenty of sunlight coming in. My problem is there is this "white crystallized material" that is collecting in the shower drain. My husband tends to think that because the shower is Travertine that it is run off from the stones, although he did put a sealer on them.

I have extreme lung problems and I am currently being treated for pseudomonas. I constantly worry about this stuff in the shower drain. I did not read anything on your website about efflorescence collecting in the drains only on buildings. Is it possible that this is what is in my drain and it's due to the regular moisture associated with shower water?

I appreciate any help you can give me. Thank you. Sincerely, H.G.

Reply: Effloresences in shower drain? Unlikely & in any case it's too small a particle reservoir to explain an indoor air quality health concern - but here are some things to watch out for

H.G., of course I'm sorry to read about your pseudomonas health worries.

If there is an effloresence problem on a building surface it is generally a salt crystalline material deposited on an above-ground above-water-level surface - because effloresence is a mineral salt left behind on a surface by the process of evaporation. It is very unlikely that the material in your shower darin falls under that definition - it's a wet area with little evaporation, and since the drain materials will be plastic or metal they won't be a source of mineral salts.

I agree that runoff or mineral deposits from tile could possibly collect in a drain, but I'm unsure what mechanism would leave that material specifically in a drain.

If you would be kind enough to send me some sharp photos of the drain and material in question as well as details about the tiles that you installed there I would be glad to comment further. If you like you can also send a physical sample of the material to our forensic lab where I may learn something further by direct examination. Use the CONTACT link found on any of our web pages to find an email and mailing address. [Note to other readers: please do not send us anything by mail without prior agreement by email. Unsolicited samples of any kind will have to be discarded. - Ed.]

Very small areas of just about anything are unlikely to themselves explain an indoor air quality problem

But more importantly, the total area and quantity of a deposit in a drain (surely no more than a 1-3 square inches) would not itself be a plausible source of high levels of a problematic indoor air particle.

Further investigation of your building for IAQ concerns

However building leaks, drain problems, or use of certain building materials in the construction of your home could be potential sources of irritating or otherwise problematic particles. A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with building moisture, or that might point to a material that is shedding or contributing to an indoor air quality problem.

While I argue that "tests" for indoor air quality alone, without taking a case history, building history, and without making a thorough expert building inspection would be unreliable, it might be appropriate to screen your home by some additional testing beyond just an inspection. Because a competent useful inspection and testing are costly, I do not recommend that step without some justification. See MOLD EXPERT, WHEN TO HIRE for help in deciding if such an inspection and testing are warranted.

As you probably know from your doctor and your reading, pseudomonas is a bacterium that is widespread in the human environment, and commonly found in both homes and hospitals. This bacterium lives in water. It does not spread through your home in air. As this bacterium can also be found in healthy people, more often people suffering from pseudomonas-related illness often have a compromised immune system.

In my OPINION, anyone suffering from a compromised immune system would want to take care to avoid living in an environment that might have high levels of contaminants or particles that are likely to exacerbate their health concerns. One group of such indoor contaminants often found in homes include various molds, some of which are often present in a home that has suffered leaks or moisture problems but that nevertheless can be hard to spot, such as some members of the Aspergillus and Penicillium families. A building screen for problem particles should thus include indoor mold contamination.

Check with your doctor

If you haven't already done so, you should ask your physician what sorts of environmental materials or exposures would be most likely to cause or exacerbate your own health problems. Those are materials for which we should first screen your home or other places where you spend most of your time.

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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
  Mildew Photographs
  Recognize Cosmetic Mold
  Recognize Harmless Black Mold
  MOLD GROWTH ON SURFACES, PHOTOS
  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
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ENVIRONMENTAL HAZARDS - INSPECT, TEST, REMEDY

STAIN & BIODETERIORATION AGENT CATALOG
STAINS on buildings - QUICK GUIDE
STAIN DIAGNOSIS on BUILDING EXTERIORS
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STAINS & Thermal Tracking
STAIN DIAGNOSIS on ROOFS
STAIN DIAGNOSIS on STONE

Thanks to reader S.M. (anonymous by request) for discussing the rate of formation of efflorescence, May 2010

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

What is the White Fluffy Stuff on Building Walls

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

How Old is the Efflorescence on a Building Surface & How Quickly Can Efflorescence Form?

Question or Age of Efflorescence on a Building

Reply

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

Frequently Asked Questions (FAQs) about white & brown building stains & deposits: efflorescence causes, significance, cures

Question: Bubbling wall surface, brown & white deposits, dusty: is this mold or efflorescence?

Reply: Expect efflorescence on leaky masonry surfaces; expect mold on organic surfaces (wood, drywall, paper) when those surfaces have been wet

Why Effloresence Forms Paint Bubbles on a Painted Concrete Wall

Can Mold Even Grow on Masonry?

Relation of indoor humidity level and efflorescence formation on masonry walls

Question: Is this white fluffy stuff efflorescence? and If So how should I clean and Paint it?

Reply: Cures for Efflorescence or "white mineral salt stains and deposits"

Question: How do I stop Efflorescence from Growing or Forming

Reply: Find and fix the moisture source or efflorescence will continue to appear

Question: I think I have Efflorescence growing out of a bathroom floor - but it's growing really fast. Will it stop once the concrete has dried?

Reply:

Question: I see white blotches where carpet squares were removed from the concrete floor. Is this a worry?

Reply:

Question: After a basement flooding we see this white efflorescence stuff - could it be from remaining floodwaters?

Reply:

Reply: A masonry sealer can slow down efflorescence formation

Question: I bleached the efflorescence spots but it returned, Why?

Reply: Efflorescence is not a biological product; it reappears due to moisture or water leaks. Bleach won't "kill" mineral deposits nor stop their reformation

Question: Is the white fluffy stuff that appeared after Hurricane Irene efflorescence or mold?

Reply: How to distinguish efflorescence from mold

Question: We have efflorescence in a wall in our apartment. It will grow back within two or three days

Reply:

Question: what is the best way to remove the white mineral salts stains on outside rendered and painted walls

Reply: Look at our stucco paint failure information, clean, seal, and repaint + find and fix the leak

Question: White crystallized material in the shower drain - could this be effloresence and is it a health risk to someone suffering from pseudomonas-related illness

Reply: Effloresences in shower drain? Unlikely & in any case it's too small a particle reservoir to explain an indoor air quality health concern - but here are some things to watch out for

Very small areas of just about anything are unlikely to themselves explain an indoor air quality problem

Further investigation of your building for IAQ concerns

Check with your doctor

Questions & Answers regarding this article

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Technical Reviewers & References

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair