Is this mold?

[Michael Drehl]

Hi,
I wanted to know if this is mold or fungus related. It is on wooden support beams. This is in my crawlspace. The crawlspace has concrete floor.
I tried to scrape it off the wood joist but it didn't flake off. It was not powdery and didn't get on my hand. Any thoughts?
How should I remedy this?

Thank you!

[Gunnar Alquist]

Hi,
I wanted to know if this is mold or fungus related. It is on wooden support beams. This is in my crawlspace. The crawlspace has concrete floor.
I tried to scrape it off the wood joist but it didn't flake off. It was not powdery and didn't get on my hand. Any thoughts?
How should I remedy this?
Thank you!

Hi Michael,

Not a lot of information to go on. How is the ventilation under the home? Do you get a lot of wetness during rains or does it stay relatively dry?

Your pic is really dark and I can't see much. I do see wood cross-bridging, which might indicate an older home (1950s or earlier) At least that's generally true here in CA.

In older homes, the contractor would often purchase lumber intended for the floor joists and use some as form lumber for the perimeter foundation. Once the forms were stripped, the lumber would be reused for the floor joists. This could be concrete that stuck to the lumber.

However, again, in a pic that dark, I cannot say for sure. Actually, identifying mold from a picture would be irresponsible.

You could get a home inspection to see what he/she says. Home inspectors are not mold specialists, but they generally know what concrete looks like.

You could get a mold test from someone in your area. These are costly.

You could get a DIY mold test. I believe there are quickie tests available where you take a sample and send it to an online outfit that would run the sample.

[Jim Luttrall]

Looks like a coating (paint) and a bunch of cobwebs and dust. Since this is not in the conditioned living area, unless this is a destructive mold that is destroying your wood, it is likely not anything to be worried about even if it is mold. There is No Way I nor ANYONE else can tell you if this is mold or something to be concerned about from a photo (especially this photo). If you are concerned, get an inspector or pest inspector that is versed in wood rot and other WDO (Wood Destroying Organisms) to take a look. Go to Hud/EPA brochure https://www.hud.gov/sites/documents/DOC_12335.PDF
for more information. I would not go to the expense of testing... I guarantee you have enough mold to detect with testing, as does every crawl space in the world, and you really don't need to know the particular name or strain. If you have enough mold to be a problem, you have a moisture problem that needs to be corrected first.
Good luck.34515

[Nick Ostrowski]

Can't tell for sure because the pic is not close enough to the joists but it kind of looks like concrete residue. I see that a lot in older houses. The lumber gets used for concrete forms or something like that as the house was being built and then reused as floor joists.

[Caren James]

Hi,
I wanted to know if this is mold or fungus related. It is on wooden support beams. This is in my crawlspace. The crawlspace has concrete floor.
I tried to scrape it off the wood joist but it didn't flake off. It was not powdery and didn't get on my hand. Any thoughts?
How should I remedy this?

Thank you!

That can be a kind of fungus that develops due to the moist around that part. If it is growing (when you see the patches enlarge) then you will know it is fungus. If it isn't growing then that must be something else.

[sar2008]

Hi,
I wanted to know if this is mold or fungus related. It is on wooden support beams. This is in my crawlspace. The crawlspace has concrete floor.
I tried to scrape it off the wood joist but it didn't flake off. It was not powdery and didn't get on my hand. Any thoughts?
How should I remedy this?

Thank you!

If you can make the closer photo with a higher quality it will be easier to tell if it is mold or any kind of fungus. In any case, this is a frequent occurrence and it will be good i you start cleaning it as it can become a big problem. Speaking about how to remedy it you can try special mold removers. I know about RMR-141 RTU (https://chemicalwiki.com/best-mold-remover/) Mold Killer. It is widely used to clean mold.

https://m.media-amazon.com/images/I/41A6jkWlZTL._SL160_.jpg
Also, you can try Professional Disinfecting Mildew, Virus & Mold Killer

https://m.media-amazon.com/images/I/41eXNVmFYjL._SL160_.jpg

If they do not help so it will be good to consult with cleaning services and see how they can help you.

[Markus Keller]

To. me, it looks more like a coating of some sort or heavy smoke damage from a fire. Pic isn't very good so hard to tell.

[michaelcparkers]

Looks like a mold. I have something similar on the bright facades of my house on the street. I;ve fought them with the help of outdoor bleach (https://clifandcleaning.com/best-outdoor-bleach/). Have you already found what has happened with your walls and how you solved this problem?