More Questions & answers about how to tell mold contamination from other building stains, debris, or particles.

These questions and replies help distinguish between harmful and harmless indoor stains, growths, deposits, dusts, & particles.

Page top photo: carpenter ant frass on a wooden wall and atop heating baseboard. This is not mold, but damp conditions inviting carpenter ants into the structure also invite mold. There could be hidden mold in this wall cavity.

This article series describes indoor stains and deposits that are not building mold or in other examples, harmless cosmetic mold. 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.

Q&A on indoor stuff mistaken for mold - #2

These questions & answers about stains and growths in buildings that are not mold were posted originally

at MOLD APPEARANCE - STUFF THAT IS NOT MOLD - be sure to check out that page.

Photo: stains on a ceiling tile merit further investigation for leaks from above.

[Click to enlarge any image]

For photos of stuff that is indeed mold contamination in buildings, see MOLD APPEARANCE - WHAT MOLD LOOKS LIKE. So many people have called us to look at things that are not mold that I'm offering some photo tips below.

On 2018-10-12 by (mod) - check back of stained ceiling tile to look for water stains when evaluating mold

Amanda

I can't tell from the photo just what we have on your ceiling tile. As this is a suspended ceiling, carefully (without falling off of a ladder) lift up, turn, and remove the stained tile and tell me if there are water stains on its upper surface or in the ceiling cavity above.

On 2018-10-12 by Amanda

These are ceiling tiles. I realized that these stains were actually a yellow dust, not sure if mold or something else but it wipes off w dry cloth fairly easy

On 2018-09-21 by (mod) -

IF you find more than 30 sqft of contiguous mold then professional cleanup is usually warranted; smaller areas are a normal homeowner or handyman cleanup job.

See MOLD CLEANUP GUIDE to GET RID OF MOLD

On 2018-09-19 by Regi

thank you... The wall is a little wobbly anyway so eventually will need replaced.

If there is an issue within the wall do you harmful? We have been here 9 years. I know mold can be harmful to people. But I think if its more exposed rather than within.

On 2018-09-18 by (mod) - mysterious hole in varnished wood wall

Looks a bit like decay, perhaps around a screw or nail hole, old, as the lacquer is coated over damaged wood near the surface. That filamentous stuff inside the opening could be a spider web or mold.

In any event, the total size of what we're seeing is absolutely trivial - itself - as a mold question. If there is a mold problem in this wall it would be in the wall interior cavity, not in the opening that we see.

Also the fact that the interior of the hole is so shiny suggests that it is old and has been coated with varnish or lacquer. If so, it doesn't appear to be an active issue.

On 2018-09-18 by Regi

Thank you.. Here is another photo of inside or the hole we were looking at.

It is a partial wood wall that looks to have been lacquered pretty good.. It is a smooth shine on the surface.

However since the pieces weren't put together well enough there is a crack at one area between 2 boards and this whole is within that crack. It is a very old house.

On 2018-09-18 by (mod) -

Regi

Kudos for a nice and sharp photo (above).

Still, booby prize for me as I can't say what the heck we're looking at.

I see what I think are water stains; if there has been water or moisture in or behind this wall material AND if the material is mold friendly (wood, paper, insulation, drywall) then there could be a hidden mold reservoir in the wall.

What is the building material involved? What is the construction of the wall?

Is this an interior or exterior wall?

Are there potential water or condensation sources in the wall?

Is the photo as shown rotated out of vertical and is that a water stain along what looks like a butt joint of two wall materials, maybe wainscot?

On 2018-09-18 by Regi

Hi there.. We found this in between a crack. This is an all wood half wall at upstairs hallway. It could be dust too but not sure. If you could please zoom into the small hole and let me know

Hello hoping someone helpful. This is a growth we recently seen. It is a crack that is in the half wall in our upstairs hallway going up the steps.

We are wondering if it is just dust or possibly developing mold. You would have to zoom into the hole. Thank you

On 2018-09-16 by (mod) - possible termite frass at wall

Hello:

The photo just below suggests to me that you are not Lisa whose question was posted earlier. Your photo looks like termite mud tubes by termites exploring to look for a desirable passage.

But then I am guessing since I have no data about what's behind that white surface in the photo: wood, structure close to ground, area of termite risks, area of water or leaks - there are more questions than answers.

But ... termites are a risk to consider.

I'd probe the area for hidden damage.

Let me know what you find.

On 2018-09-16 by Hello

Hello. I left alone for a fee days. This is the best picture I can get. Do you think it's what you said the first time. I blew at it and nothing. Just want to make sure it's nothing more. Thank you.

On 2018-09-13 by (mod) -

Lisa

Your photo shows what looks like a very tiny mold colony- or fungus - with some fruiting bodies - maybe an inch in diameter;

I also see water damage and leak stains to the surrounding wood, both in what looks like a butt joint in T&G boards and as black staining around a previously-puttied nail head.

The amount of mold in the photo is trivial: clean it off. There is, of course, a risk of a larger hidden mold area on the other side of the wood.

This little chickpea-sized mold growth would not itself make an area in your house smell moldy.

On 2018-09-13 by lisa ruschioni

hi! this just suddenly appeared on the wall inside our house this week. this wall is on the backside of our shower upstairs, so i was wondering if it's mold from a leak? there are no other spots of it visible anywhere.

also, it smells like mold but is very hard and crusty and wasn't damp when i cleaned it up.

any thoughts on what it could be??

thanks!

On 2018-09-10 by (mod) - possible insect damage through wood, insulation, drywall surface

It's okay, and I understand that it is hard to take a sharp picture of small fluffy material.

It's still kind of blurry but I think your photo is showing what looks like either some insulation, perhaps is cellulose, or some carpenter ant frass or termite mud tube explorations - perhaps mixed with insulation.

It doesn't, to me, look like mold. If you blow on it and the material rolls away on the surface as a sort of Clump or ball then it's probably the kind of material that I was guessing.

On 2018-09-10 by sheron idk

here is a btter picture. i;m wondering is it brown mold. i have a son who has asthma and my immune system ain't that good.

On 2018-09-09 by (mod) -

Idk

I'm sorry but the photo is so blurry I have no idea what the dark stuff is. [more photos above - ed.]

On 2018-09-09 by Idk

I'm trying figure out what this is. Can you please help me identify it.

On 2018-09-08 1 by (mod) - orange liquid ooze from wall

Those dots look as if there was an orange-liquid oozing out from a rash of paint bubbles. I'd be looking for

- a moisture or condensation source

- painting history that might suggest paint was applied over debris on the wall surface

and I might cut a 2x4" inspection opening to look for a leak or other problems on the cavity side of the drywall.

Or you could scrape and sand the area, seal it with a lacquer primer sealer, re-paint the area to match surrounding wall, and watch to see if problems recur, deferring the test cut until that event.

On 2018-08-20 by Anonymous

our house is very dry. We put a humidifier in our bedroom in the winter. We keep the temp around 73 during the day and 68 at night.

On 2018-08-20 by Anonymous

The dots are located under the return for the a/c unit in a stairwell. There is a 1/2 bath located on the other side of the wall in the basement. This is the only place we have noticed this. We have a very small leak coming from our dishwasher when it runs, but its minimal. The house was built in 1963, and I assume that was when this was wall was built. We painted the walls 8 years ago.

We noticed this happened several years ago, but we cleaned them off and nothing returned. We just noticed them again about a month ago.

On 2018-08-07 by (mod) - Any mold growing indoors can be allergenic or possibly more harmful.

Any mold growing indoors can be allergenic or possibly more harmful.

About using bleach, "killing" mold is not a proper substitute for removing it; bleach based or any household cleaner is fine.

See MOLD CLEANUP, BLEACH https://inspectapedia.com/mold/Bleach_Mold_Contamination.php

and MOLD CLEANUP - WOOD FRAMING & PLYWOOD https://inspectapedia.com/mold/Clean_Moldy_Wood.php

On 2018-08-07 by Anonymous

Thank you! Would bleach work too? Does this look like this could be toxic mold?

On 2018-08-07 by (mod) - black mold growth in cabinet base

Yes that looks like mold.

Use a spray household cleaner and paper towels, clean it up, let it dry, and to reduce future ease of mold growth, spray with a clear shellac or if you prefer, a lacquer primer sealer.

On 2018-08-07 by Mallory

Hi there! I found this black stain inside of one of my kitchen cabinets. A bottle of aloe gel had tipped over a few years ago unbeknownst to me and I didn't find it until months later. Could this be mold?

On 2018-08-06 by (mod) - moisture bubbles erupting through paint?

It looks as if the "dots" are moisture bubbles under paint, erupting and oozing. Where is this phenomenon occurring? Just on one wall in one area? In what area of the home? What is behind this wall cavity?

An internal partition, an exterior wall, plumbing, leaks? Interior moisture?

What is the history: age of home, age of wall, age of paint job, when the defect first appeared, indoor conditions of temperature and moisture? Paint history?

These are examples of some diagnostic questions.

On 2018-08-06 by Anonymous

This is the best photo I can get. The dots are so small, its hard to get a good focus on them. They are hard and can be scrapped off the wall with my fingernail.

On 2018-08-05 by (mod) - red liquid oozing from eruptions in wall

Cassie

Your photo is too blurry to be confident in a diagnosis but it looks as if there are tiny holes exuding a red liquid. I would cut a 2x4" hole, inspect the back surface of the drywall and the wall cavity. Let me know and show me photos of what you find and we can comment further.

There is no point in repairing the wall before the cause of these oozing red drywall spots is diagnosed.

On 2018-08-02 by (mod) -

Mallory

I'm not sure: that could be a black mastic adhesive. Take a close look for evidence of a history of leaks or water passage at

- the floor around the cabinet base

- the cabinet interior front over the kick molding and trim

- the broken edges of the kick molding

- the particleboard backer at the kick molding

In your photo I can't see water marks so I suspect that the black stuff is not mold.

Let us know what you see in those other checkpoints, especially in the floor of the cabinet interior and of course inside the cabinet at higher points if there is plumbing visible.

On 2018-08-02 20:58:22.171555 by Mallory

Our dog chewed away at the corner of one of our cabinets in kitchen. Underneath is black. Is this mold?

On 2018-07-30 19:04:59.013079 by Anonymous

Mod, this is drywall in a stairwell

This is drywall in a stairwell.

On 2018-07-30 19:01:12.706898 by (mod) - insect damage, possibly termites

Cassie I think this might be an insect attack not mold.

Can you tell me what is the ceiling material? Is it drywall or perhaps a softer fiberboard?

On 2018-07-30 17:03:39.992439 by Cassie

About a year ago we saw these hard red dots/spots coming out of the wall. We scrapped them off, wiped the wall down and basically forgot about it. Just noticed them again. When you scrape them off, it leave a little hole.

On 2018-07-28 by Mold-o-phobe

Thanks for your input. Do you recommend any particular cleanup in the case that it is mold?

The heater, which has been replaced, was in our utility closet off our living room. I’m certain the maintainer crew did nothing to clean up except wipe up the nasty water with a cloth.

Also, our vacuum cleaner was there, so I was unsure if I need to clean it and change the filters before use. There are many extreme seeming opinions on how to handle mold that I want to aim for reasonable but safe. Thanks again!

On 2018-07-28 by (mod) - black material, possibly mold, at water heater insulation

I can't say what that goop is from the photo;
Certainly if it's mold it's not a significant mold reservoir nor, in itself, large enough to be likely to be a measurable health concern.

On 2018-07-28 by Mold-o-phobe

We recently moved from a home that had many water intrusion issues and, you guessed it, mold. It cost us a small fortune.

The water heater in our new rental developed a leak around the heating element and this is what the insulation looked like when maintenance opened the access panel to check it.

Mold or rust/corrosion? The bottom of the panel also had a black substance on it.

They took zero precautions in the case that it is mold so I’m unsure what, if anything, I need to clean, etc. The water in the insulation was black and getting on my floors during the replacement of the tank.

Thanks in advance for any info. I’m feeling stressed at the thought of another mold issue.

On 2018-07-03 by (mod) -

Ken I'm not sure what that black stuff is under your carpet pad - perhaps residue from a black pad bottom? Or mold? The photo is a bit blurry - I can't say.

You could send a tape sample to a mold test lab for analysis if you must know if it's mold or not.

See DUST / MOLD TEST KIT INSTRUCTIONS

On 2018-06-30 by Ken

This [photo above] and more was under a carpet and carpet pad. Is this black mold. And if it is, is it alive? How to best treat this situation? Many thanks,

On 2018-07-03 by (mod) - black mold on floor joist

Kathy:

Those black "spots" on wood framing could be mold and might have been on the lumber when the home was framed - or not.

See COSMETIC MOLD, RECOGNIZE https://inspectapedia.com/mold/Cosmetic_Mold.php for help sorting out that question.

On 2018-06-25 by Kathy

I'm attaching a photo of the floor joists of our lake house.

Can you tell what the specks are on the board? We will have a professional come look and/or test it but was wondering in the meantime if you could say.

When you touch/smear the specks they are reddish brown and powdery I would say. I am wondering if they are mold spores?

Or?...

A type of mildew? We've had some rain come in under the house in one corner through the foundation - a gutter/french drain failure - undetected for several months. Under the house is usually very dry.

Located in Gainesville area of Florida

On 2018-06-05 by (mod) - mold stains on door

Rick,

Your photo looks as if there's mold growth on the door surface.

it's not possible nor is it necessary or even useful to identify the general and species of mold since the actions you need to take are the same regardless.

On 2018-06-05 by Rick Williams

Can you tell me what the attached photo is? It seems to prefer glossy paint but I also have some on walls with flat paint.

On 2018-06-05 by Mary

On 2018-04-10 by (mod) - carpenter ant frass on wood wall and on top of heating baseboard

Ray

From your photo and our private email, to me that looks like carpenter ant frass.

See CARPENTER ANTS

On 2018-04-10 by Ray

Would you know what this substance could be? Thanks [photo above]

On 2018-03-27 by Glennis Leech

I have orange coloured stains on wallpaper and blinds I live in a park home which we have mg0 boards which have become damp could these be giving spores off

On 2018-01-31 by (mod) - mold in dirt crawl area

I can't quite tell from that photograph but it looks as though we may be seeing a puffball fungus or a basidiomycete.

The pictures a little Overexposed. Tell me the location. Is this Outdoors or in a crawl space.

I suspect this is mold on dirt in a crawl space.

In any event if this is an outdoor fungus it's not a hazard to you if you leave it alone. If this is a fungus growing in a crawl space under a building, then the greater Hazard would probably be other molds on building surfaces in the same area.

Caused by the wet or humid conditions.

On 2018-01-31 by dmgoinghome

Does anybody know what kind of mold this is fungi, insect is it dangerous?

On 2018-01-12 by Eugene

Thank you for all the help! We will go ahead and do that.

On 2018-01-12 by (mod) - White fluffy stuff on light fixture - final steps

In any event if there are no water leaks (that would raise an electrical safety concern) I would wipe off the debris and watch for a recurrence.

I'm doubtful that there is a justification for spending on testing or further analysis if the problem is confined to such a small area.

On 2018-01-11 by Eugene

I am not sure. I asked the manufacturer and they have never seen anything like it either.

On 2018-01-11 by (mod) - White fluffy stuff on light fixture

Thanks for the added details.

Could we be seeing a reaction of paint to some contaminant that was on the light when manufactured?

There are some plastics that support mold growth, but to me this looks like it could be a paint reaction.

For mold to appear on plastic, I would expect the surface to have been exposed to high moisture to support mold growth and in that case the same growth ought to appear also on the other identical plastic light fixture shrouds in the same area.

See MOLD on PLASTIC SURFACES

On 2018-01-10 by Eugene

Hi Dan,

• Are these lights indoors? (Yes)
• Are they facing down? (Yes)
• Is the material plastic or painted metal (The material is plastic)
• Is it appearing only on one of several identical light fixtures (It is appearing on several identical light fixtures)
• Are there or have there ever been signs of water leaks from above into the light fixture or its mounting box? (Our tech said there is no visible signs of weak leaks or damage.)

On 2018-01-10 by (mod) - White fluffy stuff on light fixture

Eugene

How odd; I'd not expect mold to grow just on one surface in an area where conditions of moisture were conducive to mold growth. \

Diagnostic questions to try to identify the white fluffy stuff on your light fixture

• Are these lights indoors?
• Are they facing down?
• Is the material plastic or painted metal
• Is it appearing only on one of several identical light fixtures
• Are there or have there ever been signs of water leaks from above into the light fixture or its mounting box?\
• Also see EFFLORESCENCE
• SALTS & WHITE DEPOSITS
• And see WHITE MOLD PHOTOS

On 2018-01-10 by Eugene Park

Hello, we had a tech on site for a job and he ran into some light fixtures with dust like substance, but unlike regular dust it was snow white. Both him and I have never run into anything like this before.

Could this be mold? I have attached photos (please let me know if the photo attachment is still not working). Thank you!

On 2017-12-02 by Mike Andrews

Hello again, I am sorry to hear that it looks like Bad Mold that I am dealing with.....not a good thing.
I will check out that link to see what I am up against and the best way to deal with it.

Mobile Thank You so much for looking at my pictures and letting me know that it is mold I am dealing with
and letting me know to check the link.

[Click to enlarge any image]

Watch out: this pair of mobile home photos of extensive white mold growth indicate an extensive mold contamination hazard. This discussion is retained here to help distinguish mold from "not-mold" stains and deposits in buildings.

On 2017-12-01 by (mod) - extensive light colored mold growth on walls and ceilings of a mobile home

Mike, I saw your photos [shown above] - this looks like very extensive light colored mold growth on walls and ceilings. A home with that much mold is not safe to occupy.

See WHITE MOLD PHOTOS.

Most likely some demolition, then cleaning, and of course repair of the moisture source, will be needed before the space is usable.

See our ARTICLE INDEX to MOLD CONTAMINATION & REMEDIATION

you'll see a series of articles on mold cleanup.

You do not need to test an extensive indoor mold contamination to identify the mold genera/species as that wouldn't change the cleanup needed.

On 2017-12-01 by Mike Andrews

Hello again, I just used the Contact Email Address and sent some pictures. Just let me know what I may be dealing with (Mold- Dangerous Mold...or something else) and how I may be able to get it under control.
Thank all of you for any help you can offer in this situation,
Sincerely, Mike

On 2017-12-01 by (mod) -

You are right, photo attachment no longer works. I'll check with our developer,

Meanwhile you can send us photos by email icing the page bottom CONTACT link.

On 2017-12-01 by Anonymous light colored mold growth on walls and ceilings

On 2017-12-01 by Mike Andrews

Hello again and thanks for the link. But I have not seen any pictures like what I have.

If there's nothing even resembling any of the mold photos in that like I said and then what you have may not be mold.

But of course I would be glad to see some photos. You can attach pictures by using the little square frame next to the comment box when you are writing a comment. Or you can use the page bottom contact like to send us photos

On 2017-11-30 by (mod) - how to get moldy mobile home under control

Mike

The photos of this page of what mold does look like on building surfaces might be helpful to you.

MOLD APPEARANCE on VARIOUS SURFACES

I'm not sure how well it will work but you can also try posting some photos particularly sharp close-ups of what you suspect might be mold right into your comment on this page. The little funny square picture frame to the right of the comment button will give you an opportunity to post a photo

On 2017-11-30 by Mike Andrews

Hello there, You say that a lot of things that look like mold may not be mold or harmful. This is pics from closed up vacation Mobile Home that has not been heated or central A/C turned on in aprox 7 years and walls for last couple of years been showing some white markings.

Aprox Two Months Ago when I was there I did Not Notice The Ceilings had any of those Round Puffy Circles and they are in Bath Room and 2 of the 3 Bedrooms that are beside them and Walls Way Worse.

The ceiling is drooping pretty bad also esp in 3rd room where I Do Not See Circles Yet? (The Hallway Does Not appear to Have The Problem yet....??).I looked at Roof and not been coated in maybe 15 years...but not too bad.

I think Moisture maybe from under as well Full Skirting with really no vents and it does sit on slight hill so no standing water....But on that side Leaves Pile Up Every Year and last Year Did Not Rake away from side of Mobile Home Till a Couple of Months Ago....

Now They Are Back For The Winter. This is a 1973 London 12' x 70' single wide in Southern Maryland Near VA. Does this look like Dangerous Mold?? Or Is This Something Else?? And I Know it is a Large Area....

But Is There Any Realistic Way Of Getting it Under Control. I am going to try and upload some pictures of what this looks like. Thank You in Advance For Any Info Or Suggestions on My Situation. Sincerely Mike

On 2017-08-29 by (mod) - white fluffy stuff that is not mold but efflorescence

Tori

be sure to review the EFFLORESCENCE photos at https://inspectapedia.com/Wet_Basements/Efflorescence-White.php

Home test kits for mold can only grow about 10% of all of the mold genera in the world, so it's not a comprehensive test, and more, in your case airborne mold spores from anywhere, coming in a window, might settle on and grow on your culture - that's not going to help your question.

Efflorescence is a mineral salt that grows where there's moisture - it's very different looking from mold, as you'll see in the article I recommended.

On 2017-08-28 by Tori

I'm trying to figure out if the white fluffy stuff on my basement wall is mold or mineral efflorescence. I bought a test kit at Home Depot and it's the sample is beginning to grow. Would mineral efflorescence grow in a mold testing kit?

On 2017-08-15 by Ana

I have wet and torn duct insulation in a basement laundry room I discovered leaks and what appears to be mold. May I send pics?

On 2017-08-14 by (mod) -

Sue:

I can't make a useful guess without knowing more about the home, location, age, construction, environment, leaks, moisture sources, air circulation, and of course seeing the 2x4s. It could be a leak stain, mold growth, or some other deposit.

If you'd like to send me a few photos up close of the white areas and more distant to let me see the context of the framing and the garage interior, I'll be glad to comment further. Use the page top or bottom CONTACT link.

On 2017-08-13 by sue

what makes the 2x4s in our garage to turn white.only one side of garage

On 2017-08-03 by Tabatha biggar

Hi I have found some fungus looking stuff in my basement I thought it was good that my teens hid. I touched and when I picked it up it puffed so I dropped it right away I have a picture of it. But I do not know how to attach it on here

On 2017-07-05 by (mod) -

Sounds like a combination of spills and perhaps mineral salts or efflorescence deposits on the concrete - a common result of moisture on or below masonry.

See EFFLORESCENCE SALTS & WHITE DEPOSITS for more details and let me know if that's what you're seeing.

On 2017-07-05 by Connie perkins

Also thick black stuff on concrete in garage if water pored on it it swells and spreads also white cicles if you put water on they swell are syrup like put paper towels on.picked up dry paper in morning.spots bigger.funny spots on paper.

WET them spots enlarged come thru paper look like clear jelly.peeled some off burned skin bad .tried to wash off absorbed into skin leaving raised welts same size on my hands got in sink they absorbed into sink leaving marks on sink won't rinse seems waterproof and won't towel dry.

Next morning looked and spots dry. Experimented put wet paper towel on them waited 15 min.watched spots go onto paper peeled up paper .out of sink and on paper parted paper towel and they where inside peeled off with toothpick. I call them jellys.

Spotted in different spots on floor.put wet paper towels on floor let dry picked up stains on floor gone can see on paper towel.put in jars.Hubby thinks I'm nuts.so wet one towel made him watch and peeled them off.Don't want anything to do with them.I'm nuts.when I get hands or arms wet.welts raise up and itch and sting.will they harm me inside.

Have small pieces of hard orange. Pieces tracked thru house from water damaged garage.orange smears on walls.clorox makes worse .we do have efferescent mold on foundation and under house.black mold on insulation wall leaks above crawl space for 7 yrs.

also kitchen sub floor very wet from leaking sink pipes linoleum cracking and cabinets growing black mold bleach no help.cabinets crumbling with black white and orange color underneath them.can you help

On 2017-07-05 by (mod) - tan stains on the brown cage members of my pool

Bill

Sorry I don't know what cage members are. You can use the page top or bottom CONTACT link to send photos if you like, and perhaps I can comment further

On 2017-07-04 by bill thompson

i have tan stains on the brown cage members of my pool

On 2017-06-18 by (mod) - glitter stuff on wood

Sorry but I don't know from just your text what you are seeing. You're welcome to use the email found out our page top or bottom contact link to send photos for comment.

On 2017-06-17 by Margie

Currently renovating a house built in 1928, under the stairs is a closet that has rough hewn wood. On the wood is what looks like glitter, it is clear to white and is evenly distributed over the wood. Any ideas?

On 2017-05-27 by Josh blue green stain on floor joist in crawl space

Looking to buy home that has a blue green stain on floor joist in crawl space. There is also a puddle of blue green liquid. Any thoughts on this. I have been searching everywhere nd cannot find anything. Inspector seems to think it was some sort of treatment for pest or mold.

There is some old mold stains and some dark mold on some of the old duct work.

On 2017-05-02 by Anna - fine dust from my laminate floor turn into jelly bubbles when wet

fine dust from my laminate floor turn into jelly bubbles when wet, where these fine dust come from?

My house is very clean, I dame mop my floor every day. but even then, when I run my hand over the floor, my hand will have some fine dust and when I wash my hand, I notice
there are tiny jelly bubbles in my fingers, where those these bubble come from?

On 2017-03-02 by (mod) -

Chris:

Really I can't guess reliably from an etext.
I looked at your photos: they were a bit small and unclear. Could be mold, insect deposits, something else.

On 2017-03-02 y Chris

Should be "scraped", not "scraped".

Hi-

We recently had a drop ceiling removed from part of our unfinished basement that was installed by a previous owner. On the now exposed wood panels, I found these really hard small black spots in a random pattern.

They must be scraped off with a finger nail or hard file. There is no moisture in the spots or the surrounding wood. Also, there is no smell. Do you know what these are? Do I have a problem? Any help or expertise is greatly appreciated.

I sent an email with pictures too. Thanks!

On 2017-02-24 by Black shiny stains on wall

There are shiny back but shiny and glimmers in the light i cannot remove then, what are they

On 2017-02-11 by (mod) - cotton stuff on attic rafters

You can use the page top or bottom CONTACT link to send us sharp photos for comment, Elaine.

On 2017-02-11 0 by Elaine

it is not mold but looks like cotton on the rafters in the attic

On 2017-01-08 by (mod) - gray stuff on floor surfaces

I can't guess what gray stuff is in your home. The most common house dust components include fabric fibers, skin cells, animal hair and dander.

Often you can send a dust sample to a forensic test lab and they can identify the dominant particle - such as cellulose insulation (that's gray) that can in turn help you track down the probable dust source.

On 2017-01-08 by alskite

During the last few months i have noted a fuzzy gray looking like cotton everywhere on my wooden floors.

No matter how often I vacuum or sweep I see them again. I have a dog and a cat and I know it is not coming from them. Their hair collor is different. It is not coming from the cooling/heating vents because I never see them over the couch, table, chairs or coffee table. Does anyone have any ideas?

On 2016-12-17 by (mod) -

Sure it's possible. I've often found dried-out Trhicoderma and sometimes Aspergillus under or between layers of old flooring, but no one can know from a simple e-text just what's below your floor.

On 2016-12-12 by Marco green powder

Hello,
we removed some hardwood in our 1950s house and found green powder / dust underneath. Could that be mold of some sort?
Thank you,
Marco

On 2016-12-02 by Anonymous

You mentioned there were other ways to check for mold if I don't have the money. What is it. I have been sick since I bought this 1929 house in 2006

On 2016-11-20 by (mod) -

AHA I found this page as well as your email, Paul. I've take a look at your photo showing black mold growth on a white painted surface near wood framing. I couldn't tell if I was looking at drywall (mold friendly material) or painted wood-based insulating board (not quite as mold friendly)


Paul:

That looks like mold growth to me, and I suspect there may be other mold growth on the other side of what looks like drywall or plasterboard. IF it's wood-based fiberboard or insulating board, then the mold might be just on the exposed, painted surface.

If there's less than 30 sqft of contiguous mold it's usually a DIY project for healthy people. Search InspectApedia.com for HOW TO CLEAN UP MOLD to get detailed advice and let me know if questions remain.

On 2016-11-20 by Paul

Hi there,
I am concerned that that streaky black splotchy pattern I found under my bath room sink may be mold. It is however difficult to tell, I am untrained and have had trouble finding reliable information I have sent a photo through the contact link.
Thanks,
Paul Weaver

On 2016-11-13 by (mod) -

Rene

Please see your photos and a detailed reply along with advice at https://inspectapedia.com/mold/White_Mold_Pictures.php#Wall_Fungus

On 2016-10-31 by (mod) -

Rene your photos are a bit blurry but I see what looks like dark mold as well as water stains. The white crystalline material is more likely efflorescence - a mineral salt left when water passes through and dries off of masonry (stone, brick, or perhaps plaster).

You can also use the page top or bottom CONTACT link to send photos for comment.

On 2016-10-29 by Rene

Hi, while cleaning out the 4 foot crawlspace of my split level house I noticed a black patch a foot long on the drywall. Decided to remove it and look behind. Found a white crystal-like substance on all the 2x4s. In one spot it looks like it is growing away from the 2x4 onto the vapor barrier in a oyster shell shape.

This is an outside wall, insulated with fiberglass and covered in drywall. It also is where the water pipe is located for the outside use. The lower right corner has a lot of dark patches on the wood. We've owned 10 years and never had any water leak. Any way I can attach or send a photo? Thank you.

On 2016-10-24 by Ritika Murthy

This stuff I see growing in my house and i can not figure out what it

On 2016-09-17 by (mod) - home flooded in NW Louisiana in March 2016

Karl, if the masonry was under water it was contaminated by sewage levels in the floodwaters; in addition to disinfection, it may take some time to dry out; during that dryout you might continue to see staining or efflorescence You're welcome to use the page bottom CONTACT link to send us photos for comment.

On 2016-09-17 by Karl Rothenberger

Our home flooded in NW Louisiana in March 2016 - water grossly contaminated from bayou, dead animals & septic systems in our neighborhood. Water stood in house
2 1/2 feet for 5 days.

Home was gutted- & decontaminated- however our brick fireplace & that of several of our neighbors remain stained. Grout discolored white, & our light brown brick has dark brown spots inconsistently. We had cleaned by contractor & only worsened discoloration. Do we need to be concerned about contaminates & any way to repair discoloration ? Thank you

On 2016-09-03 by (mod) - what kind of mold is this?

Estelle,

No one who is informed and honest would pretend they could identify a mold from an e-text. There are over a million mold genera/species, many of them dark in color, ranging from harmless to harmful.

Adding complexity to the question and reply, conditions that make mold grow in a building will virtually never produce just a single mold genera/species as there are at least 200 species that love wet building interiors and thus that may flourish indoors. Probably more but the 200 would be the most-frequently-found group.

The danger from any mold contamination depends on

- the amount of moldy material

- the various genera/species present as well as the specific growing conditions and host materials as toxicity varies over time and material even for the same species

- movement of spores and MVOCS in the building air

- sensitivity or health vulnerability of occupants.

See MOLD / ENVIRONMENTAL EXPERT, HIRE ? at https://inspectapedia.com/sickhouse/IAQ_Investigation.php for help deciding how to proceed.

On 2016-09-03 by Estelle

We've had significant water and black mold damage and now after pulling carpet we have what looks like roots growing everywhere with a moldy foul smell. What type of mold is this? Is it dangerous?

On 2016-08-11 by (mod) -

Having usually solved problems with my carpenters' hammer, I understand completely.

My OPINION is that there are two sorts of real estate agents.

1. listing collectors: promise the moon, get the listing, earn your share of the commission if you never lift a finger to do anything else for the client. I think many if not most agents are in this group.

2. selling agents: some agents work very hard to advertise, show, and sell your property. As the selling agent the earn (often) the same amount as the listing agent unless one agent is both listing and selling agent.

If your agent is a type2 then that person might be expect to

1. give you advice on marketing the home: cleaning, clutter removal, pricing, baking an apple pie, whatever.

2. keep you informed as the home is shown, updating you on what sorts of concerns or reluctances buyers express and helping you decide if your price is right.

A real estate professional is under a lot of pressure, as it's a low-volume, high-fee business. But at the end of the day the agent is going to get paid thousands of dollars. For that they ought to talk to you.

On 2016-08-10 by Lee

Mod, thank you so much for the excellent and timely response. It is almost comical how selective my perception and thinking can become, straining to find reasons why 70 groups of people have toured my beautifully staged house and not made offers.

The simple answer is that this paint is most likely overspray from when the masonry wall below was originally painted. Duh.

I was worried about mold in the attic, so now I have mold on the brain. Sort of like when all you have is a hammer, everything looks like a nail. Thanks again for your help. Now I can lather up some other imaginary problem to worry about. Or better yet, stop worrying. -- Lee

On 2016-08-09 by (mod) -

Lee,

To permit showing your photos to other readers, to allow their comment, and to provide space for my own detailed reply, I repeat your question and give our answer in the article above at

https://inspectapedia.com/sickhouse/Stains_Not_Mold.php#White_Stains

DO let me know if questions remain.

Daniel

On 2016-08-09 by (mod) -

RE-Posting

Lee said:
There is a white, flaky, crusty substance in my basement on the floor joists around the outside perimeter in the laundry and utility room. The pattern looks like mold, but the color is wrong. I posted photos on my Google Drive for public viewing. Short URL is ... .

I've had two home inspectors through the house in three years. One for my pre-inspection before I bought the house, and one before putting the house on the market to sell. Neither one called it out. But I'm over 90 days on the market with no offers, below market price in a good neighborhood, and wondering if this stuff may be scaring people away that are too polite to mention it. Your feedback is welcomed.

Question: tests to determine whether or not a substance is mold

(May 19, 2015) Drew said:

Great website! I was wondering whether if you anyone on this site had ever heard about completing any tests to determine whether a substance was or was not mold.

I am particularly interested in determining whether a something on a wall is dirt (soil) or fungal growth, and I had read that you can add a droplet of bleach to your suspect substance to distinguish.

The bleach will readily be taken up by the mold and be stained while soil would most likely remain its original color. I've also been able to use a portable microscope with 120X magnification and have been able to see mycelium, but at times this is also hard to distinguish between dust/dirt/hair. Thanks!

Reply:

Drew

The "bleach" test is nonsense. Plenty of materials will respond to bleach by a color change. "Soil" is a bit of a broad term for me. "Dirt" on a wall could for example be oil and skin cells from a human or pet, smoke, or other deposits.

And no, I'm doubtful that 120X is sufficient to identify the particles you ask about. I'm typically looking at 400x to 1200x and make use of polarized light, phase contrast microscopy, and other methods such as microchemistry.

Finally: in mold samples we may not see mycelia, we may just see spores, or fragments of fungal material.

See MOLD APPEARANCE - WHAT MOLD LOOKS LIKE

Question: white crystal substance is building up in the corner of the wall

AUTHOR:bennettboyone (no email)

COMMENT:What's this white crystal substance building up in the corner of the wall

Reply:

EFFLORESCENCE SALTS & WHITE DEPOSITS

Question: black mold on concrete?

(July 8, 2015) Larry said:
Will black toxic mold grow outside on a concrete foundation?

Reply:

There are mold genera that will grow on most surfaces, but more likely you're seeing an algae.

See STAINS on STONE, STUCCO DIAGNOSE & CURE

Question: white flaky substance on Virginia log cabin wood surface

(July 13, 2015) Debbie said:
We live in a log cabin in VA at 3000 ft. We don't have air conditioning and don't need it. However, there is a dinner plate size area on a wood wall that has a white, flaky substance on it that drifts down to the surfaces beneath it and is easily brushed off.

I've tried putting white vinegar on it and putting bleach on it, thinking it might be some sort of mold. But, it just keeps growing back. Any idea what that could be and how to get rid of it?

Reply:

If the surface on which you see white stuff is masonry I suspect it's mineral efflorescence: EFFLORESCENCE SALTS & WHITE DEPOSITS

If the area was previously painted,

see PAINT FAILURE, DIAGNOSIS, CURE, PREVENTION for more about peeling paint on building surfaces.

White stuff on a wood log surface could also be a mineral salt deposit IF there is nearby masonry such as a stone or brick chimney.

White stuff on a wood surface could also be dust from an old house borer or powder post beetle, though I'd expect that dust to be more yellowish (wood color), and it wouldn't appear in a round dinner-plate sized patch it would follow a wood member along the grain and would probably be accompanied by tiny borer holes.

See POWDER POST BEETLES

Look for water leaks in the stain area;

Use the page top or bottom CONTACT link to send me sharp photos for further comment.

Question: yellow film on surfaces in my office

(Sept 15, 2015) carla said:

There is a yellow residual film coating surfaces in my office. I know the landlord is not current with changing filters in the HVAC system, and the complex is older. Could it be mold? Needless to say, it's very disconcerting!

Reply:

Mold growing on a surface would not appear as a smooth, uniform, homogeneous dust-like deposit. If the dust problem is severe and its source is not visually obvious, it may be worth collecting a tape sample to send to a forensic lab for analysis, as that can point to a dust source.

Search InspectApedia for DUST SAMPLE COLLECTION for detailed procedures.

Question: condensation on floor joist insulation in a Salisbury North Carolina crawl space

(Sept 26, 2015) Anonymous said:
I live in Salisbury, North Carolina. Two summers ago, I noticed in my crawl space that my floor joist insulation was wet and my insulated air condition pipes had condensation to the point of water dripping off of them.

(Sept 26, 2015) Richard Callahan said:

I live in Salisbury, North Carolina and have been living in my ranch style home for 29 years. Three summers ago, I noticed in my 1750 square foot crawl space that my floor joist insulation was wet and my insulated heating and air condition duct pipes had condensation to the point of water dripping off of them.

Also, I had no 6 mil vapor barrier down because it was not required at the time we built the house. So to partially remedy the situation, I removed and deposed all of the insulation and I immediately installed a black 6 mil vapor barrier in the whole crawl space.

Upon inspection of the floor joists, I found that I had a graying mold or fungus on my floor joints that stopped at the lowest level of the insulation. I have always had 16 automatic vents and I have a 4 foot square crawlspace screen for the summer months and a 4 foot square solid door for the winter months.

This mold or fungus does not to appear to have visually grown. In fact, I can take my finger or a cloth and it wipes right off the floor joists. My plan is to send you some representative tape samples and pictures to confirm mold, fungus, or something else.

After hearing back from you and assuming I do not have a serious problem; I am prepared to start the following action plan: ]

1st: Wipe & clean all of the joists and duct pipes with a moldicide or fungicide.

2nd: Install brand new crawl space insulation.

3rd: Roll and dispose of my old 6 mil vapor black barrier since it is contaminated with mold or fungicide spores and then replace it with new 6 mil clear vapor barrier.

Over the last two years I have taken metered moisture content measurements in the floor joist which have ranged from 35% - 60% with the highest percentage being in the summer time. I look forward to your thoughts and recommendations before I send the tape samples and after. Respectfully submitted, Richard Callahan

Reply:

Richard: your plan sounds quite reasonable except for one missing but key step: dry out the crawl space - see CRAWL SPACE DRYOUT - home

Please do not send us environmental samples without prior agreement by private email correspondence.

Insulation that was wet should bee replaced and the exposed surfaces cleaned; the steps you describe sound reasonable but to be effective you must first accurately diagnose the cause and thus find the cure for high crawl space moisture levels. It sounds as if you need to enclose the space and make it a conditioned, dehumidified area.

Question: cluster of white rectangular formations under a pipe

(Oct 15, 2015) Donna Miller said:
Hello- We replaced the ceiling below a bathroom that had a very old since fixed leak. all was dry inside.

I am perplexed by what looked like a cluster of white rectangular shaped formations that were in just one spot under the pipe. Bright white. Any idea at all? I have a picture. Thank you so much-

Reply:

Use the page top or bottom CONTACT link to send us photos for comment.

Question: white substance on wood furniture

(Feb 25, 2016) Mary said:
When taking pictures of an older, vacant home we are purchasing, they revealed a white substance on many of the pieces of wood furniture. Is this dangerous mold and should we be concerned?

Reply:

Mary I don't know what is on the furniture; If the wood furniture has been in a damp location the deposits could be mold; water will also cause white bloom and discoloration on varnished or lacquered wood surfaces, below the coating. Such deposits are removed by re-finishing the furniture.

Take a look at the under-side of the furniture where typically there are un-finished wood surfaces. As those surfaces pick up moisture more readily than coated wood surfaces, that's a better place to look for mold contamination.

Question: white dust collects on shoes, clothing. Hard to remove

(May 8, 2016) Sali said:
I have a white "dust" that seems to collect on my leather shoes, leather tags of my jeans, my jeans themselves and even on polyester. I can't just wipe it off. I have to wipe it off with water or a leather cleaner to remove it or I have to wash it. It is not mold (I had it tested) but it continues to be on my clothes.

1) How can I determine what this substance is and

2) do you have any clue what it may be?

Reply:

Sali:

IF the items you describe are in a wet or damp area the white stuff could be a mold growth such as Penicillium sp. or other light colored molds.

You can send a tape (or vacuum) sample of the dust to a forensic laboratory for particle identification. See the EXPERTS DIRECTORIES at page top.

Question: recurring stains on a wall-to-wall carpet

(May 18, 2016) PAULA BREEN said:
Your site is very detailed and helpful but I am still puzzled about recurring stains on a wall to wall carpet in a bonus room (space finished over a garage). The room was finished and the carpet installed by a previous owner.

We have ahd the carpet professionally cleaned several times in the last 6 years. In thelast 6 months new stains have appeared that we are cxertain are not caused by new spills. Perhaps this is residual post cleaning result of too much moisture during the cleaning process.?

These stains are mostly brown and many are in a cluster of roundish spots ranging from 1/8 inch to 3/4 inch in size. Could this be coming from the carpet pad or from the subfloor? How can I send you a picture ?

Reply:

Paula I'm baffled too - round spots? I'd pull up carpet to look at padding and subfloor below for clues.

When a beverage or food has spilled on a carpet, even if the carpet looks clean there may be enough organic material to cause visible stains (fungal growth) to recur. But clusters of round spots: sounds as if there was a splash or spray combined with recurrent moisture.

Question: thick white dust on upper levels in my Condominium

(May 23, 2016) Suzanne said:
I live in a 3 level condo for the past 13 years. I have had problems with a thick white dust only on the upper level.

It lays on the furniture, the bathroom floors, the bathroom vanities, some mirrors and the waste can. When I clean it, it comes back in 3 days. I had the air ducts cleaned, the furnace and air conditioner, carpets cleaned

To continue... The furnace & air conditioner replaced but still have this thick white dust. I now have a lung disease and cough constantly! I have hired people to look at it and for mold. After spending lots of money I still have not had any solutions! Please help!
Thank you!

Reply:

Suzanne:

As you cite a related illness and may be at extra risk, why not send a dust sample to a forensic lab for analysis. (Not to my lab). The lab can tell you the predominant particle types; that in turn may suggest the particle source as well as hazard level.

Question: air purifier did not stop dust and stain problems

(June 1, 2016) Margei said:

[Paraphrasing] There are recurrent dust and stain problems in my home. I bought an indoor air purifier and have been running it 24/7 but it has made no difference in the dust and stain situation.

Bye the way I have no pets.

Reply:

I can't guess from e-text what you're looking at, Margie. I can say that no indoor air "purifier" purifies air nor can it ever remove a problem source any more than waving a vacuum cleaner wand in the air in the kitchen will suck up the dust bunnies from under the living room couch.

What's needed is to find the source and clean it up or fix it. It might be worth sending a settled dust sample to a forensic lab (not ours please) for identification of the dominant particle as that can suggest the problem source.

But first check with your neighbours; if everyone has the problem it's a building problem or maybe street dust from outside.

 

...

Continue reading at MOLD APPEARANCE - STUFF THAT IS NOT MOLD or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see MOLD APPEARANCE, STUFF THAT'S NOT MOLD FAQs-3 - more recently posted questions about stuff that might or might not be mold, photos, comments, advice.

Or see these

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  • STAINS in BUILDINGS, FAQs
• MOLD APPEARANCE, STUFF THAT'S NOT MOLD - FAQs
• MOLD APPEARANCE, STUFF THAT'S NOT MOLD FAQs-2
• MOLD APPEARANCE, STUFF THAT'S NOT MOLD FAQs-3
• MOLD / ENVIRONMENTAL EXPERT, HIRE ?
• STAIN DIAGNOSIS on BUILDING INTERIORS

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