Thread: Help me Identify Black and Yellow Growth in Crawl Space/Basement

Hello,

I need some assistance in identifying some unknown (to me) substances found on floor joists and the bottom side of sub floor in various locations of my crawl space and basement. There are three distinct varieties found. One is a pale yellow to white color, one is black and looks almost like charring (but isn't), and one is dark brown or black and somewhat stringy.

In all cases the areas are dry. All of the lumber seems to be fine; it is not soft, rotten, bowed, curved, swollen, nor does it puncture easily.

I am located in Charlotte, NC. The house was built in 1941.

Any help in identification would be very much appreciated. I am happy to provide any additional information as requested.

Thanks in advance!

Black and Yellow.jpg
Black.jpg
Hanging BrownorBlack.jpg
Yellow and White.jpg
Yellow.jpg

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Does the crawlspace have a dirt floor? How is the CS vented, exterior vents, vented to basement, not vented to exterior?

Sure looks like some form of fungi/mould growth.

Some form of fungus.
The black part looks sprayed on. Could be a treatment for the fungus.
Clean it up, and apply a fungicide.
Fungus does not grow without moisture.
Find the source of moisture and correct it.

Originally Posted by Raymond Wand

Does the crawlspace have a dirt floor? How is the CS vented, exterior vents, vented to basement, not vented to exterior?

Sure looks like some form of fungi/mould growth.

The crawlspace and basement area are a continuous space. It is vented with crawl space vents around the exterior wall.

The crawl space is a dirt floor, while the floor and half walls of the "basement" are concrete and brick. It is clear to me that moisture is not being controlled as it should be - there is no vapor barrier in place.

I am mostly hoping to find out if this is a fungal growth that is dangerous in anyway. If so, I will need to remove it. If not, I will take steps to better control the moisture and hopefully limit further growth.

Thanks

Originally Posted by W. F. P.

Hello,

I need some assistance in identifying some unknown (to me) substances found on floor joists and the bottom side of sub floor in various locations of my crawl space and basement. There are three distinct varieties found. One is a pale yellow to white color, one is black and looks almost like charring (but isn't), and one is dark brown or black and somewhat stringy.

In all cases the areas are dry. All of the lumber seems to be fine; it is not soft, rotten, bowed, curved, swollen, nor does it puncture easily.

I am located in Charlotte, NC. The house was built in 1941.

Any help in identification would be very much appreciated. I am happy to provide any additional information as requested.

Thanks in advance!

The white looks like white wood destroying fungus, which would be supportive of the brown "stringy" as that would be brown wood destroying fungus. You stated the wood is dry, how did you test that? Modern milled wood is kiln dried, a 1941 house would not have kiln dried lumber, but rather air dried, which is porous as the cells are open. The moisture content of air dried wood fluctuates with the humidity. Kiln dried does not as the sap is pulled out of the wood and partially seals the surface. Since this is a crawlspace, just because it is dry now, does not mean it is dry all year long. Is there a musty smell?

As far as the black goes, you noted it is not charred. Do you know if the house has any history and you probably have not lived in it for the past 54 years. It looks like smoke soot. After 40 years you may not be able to smell it.

I do not know how your crawl space is insulated as no insulation is present. That will cause a condensation point at the wood where the cold of the crawl space meets the warm of the interior. I doubt that the ground has a full vapor barrier as it was built in 1941. All crawl spaces are damp, except in very dry climates, which you do not live in.

There are some old chemical pesticides that can and did discolor wood, but they do not look like this.

Need a picture of the crawl space walls and the exterior perimeter. Type of soil.

Brown and white wood destroying fungus is not dangerous. White grows very slowly over time. Brown is aggressive and sends out the stringy part to get moisture. Both destroy wood, it is the natural decay process.

Scraping it off will do no good. Spaying it will do no good.

Once you find and shut off the moisture it will subside and the white will turn yellow or a hard brown. Then you can rename it.......to dry rot.

You will find that the wood at the white and brown areas will be very soft.

My suggestion would be to have it tested instead of trying to get it analyzed from photos on an internet forum.

Originally Posted by Jack Feldmann

My suggestion would be to have it tested instead of trying to get it analyzed from photos on an internet forum.

Gee Jack, you just single handedly negated the entire purpose of this site. LOL!

Originally Posted by Jack Feldmann

My suggestion would be to have it tested instead of trying to get it analyzed from photos on an internet forum.

Ditto, but it shor looks like fungi.

I have had an encounter with 'poria' fungus. Not sure if that is proper spelling, or full name. Whether your picture shows this type or not I don't know, but if so, this is a very aggressive wood destroying fungus - and you want to have that identified and treated before it gets out of hand.
My experience was in a house I inspected that had poor ventilation, but was also near a golf course where a constant supply of moisture was given to the soil. The house was eaten up in a relative short period of time. Do you overwater your yard, live near a stream or pond, or golf course?

...is this better?

Sorry guys - dont know why it repeated the comment 4 times.

It kept giving me a 'data base' error.

Originally Posted by Chris Weekly

Sorry guys - dont know why it repeated the comment 4 times.

It kept giving me a 'data base' error.

Yes, Brian wants to know about the error on another thread. He is working on it.

Originally Posted by JeffGHooper

Yes, Brian wants to know about the error on another thread. He is working on it.

Got it! Thanks, JeffG

Originally Posted by Chris Weekly

Got it! Thanks, JeffG

When that happens, edit your comment, delete the repetitions, submit the editted reply.

What Jeff says is based on solid fact. The actual species does not matter very much. It may not be Poria, which has a web that spreads over the surface. Doesn't matter which species. The fungi are eating away at your house. They are likely to stay down in the crawlspace if your living space is dry.

It doesn't hurt to scrape the fruiting bodies off, exposing the wood. Then there is a borate solution you can apply that might kill some of the root, which is in the wood. The fungi draws moisture from the wood cells and that takes the strength out of the wood fibers.

I would report it as past moisture stains dry at the time of inspection and recommend further mold inspection including installing vapor barrier in the crawl space.

Fred Sweezer Sr.
Home Inspections in Long Beach, Los Angeles, Santa Ana and Surrounding Areas | Long Beach Home Inspector

Originally Posted by Fred Sweezer Sr

I would report it as past moisture stains

Look like current stains as I can see them / and fungal growth. What does a "past" stain look like?

Is it not, stained or not stained? Scratching my head????

Here is an article about pine being infected before being installed.

Core77 / A Raw Materials Nightmare: The Blue Pine Disaster, Part 1