Looks like a black mold problem

[Skq914]

Basement window. Top part made of Sheetrock. Outside wall is brick. Saw this (see photo). I covered the interior side with plastic to avoid breathing this crap in. Plan on removing from the outside so as not to contaminate the house. Any tips how deep this is and if it’s just the Sheetrock or would this go behind things?? Looking for tips on how to fully mitigate this. Thanks.

 

[Snoonyb]

Welcome.
We'd see this in rooms were was limited air circulation which prevent the normalization of humidity, as well as limiting consistent conditioning.

Were it I, I would mix 50/50 bleach and water and wipe the mold off, or just plain bleach, and rubber gloves.

 

[tomtheelder2020]

Snoonyb is right that moisture is the problem. No matter what you do about the mold, if the moisture source remains the mold will likely come back. When I had similar I removed the sheetrock and found mold on both sides.

The color of the mold is pretty much irrelevant to it being a problem. The black mold that doesn't affect me might make you sick and white mold that doesn't affect you might make me sick. Any particular strain of mold might affect one person but not another. Most of the "toxic mold" industry is a scam but that doesn't change the fact that many people are affected by mold. Where you see it, fix the moisture source and clean up/remove the mold. Never hire a home inspector or pest control inspector until you are sure mold is not present.

 

[PJB12]

Hello Skq914,

As part of my job and while in university, I took many classes regarding sanitation, environmental hygiene and similar areas of disease prevention and mitigation. Some also were FDA classes and some were USDA classes. Therefore, what I am going to say below is true. (Others here will disagree.)

** Never, Ever spray, wash or mist mold with chlorine containing products. Also, don't use these in the vicinity because colonies too small to see are present nearby.

Why?
Most mold species have a defense mechanism that is activated when exposed to chlorine. Even opening a container of chlorine product near the mold will activate the defense mechanism. This defense mechanism will spread the mold. (The mold you see will be killed, but see "Spread Mold?"

Spread Mold?
The mold will throw spores when the defense mechanism is activated. In a laboratory demonstration, we saw mold spores being thrown up to 500 cm away! With the slightest air current, the spores went much further. When the spores landed, they started growing new colonies.

How To Kill It Without Spreading It-
The most effective & chemical free way to kill the mold is with steam. A wall paper steamer can be rented easily.
Water drenching over 180-F will kill most molds, but not all & not all spores.
Household 5% white vinegar kills many (not all) molds & spores without activating the defense mechanism in about 10 minutes. For porous surfaces, it is not very effective deep in the surface.


How To Clean Up The Surface-
After the visible molds & the invisible nearby molds are 100% dead, dead, dead- Then you can use chlorine to get the black, pink &/or brown residue out if you wish. Finish with a soap & water scrub and rinse.
Washing soda also makes an effective scrub to remove the dead stuff. (As do TSP and Dirtex)
Hydrogen peroxide is a good cleaner, too. (Not always a good killer of molds)

How To Prevent Mold From Ever Growing On A Surface Again-
Quaternary Ammonium compounds will prevent mold from ever growing again if not rinsed off. It must be 200 ppm or higher concentration. Do not use an organic cloth. There is high uptake of quateranry ammonium into, for example, cotton cloth.

If your cleanup missed some spores, the quaternary ammonium will prevent the spores from ever growing. (Actually, on active mold, it will kill any spores and prevent the existing mold from growing- but it won't kill the mold itself. )

Silver plating the surface will also prevent mold forever. So, just in case you're a rich guy...

Where To Get Quats?
Most grocery and hardware stores sell quat containing products. But, the PPM is not always stated. Some have perfumes and dyes that can interfere with the method of action.
Restaurant suppliers have fragrance free quaternary ammonium for use in low temperature dish washing machines. Hospital suppliers also stock it.

 

[Snoonyb]

Interestingly, every place I used bleach, either 100% or never more than 25% dilution, to remove mold, over 70+yrs, never returned.

 

[PJB12]

Interestingly, every place I used bleach, either 100% or never more than 25% dilution, to remove mold, over 70+yrs, never returned.

I knew I'd get lip about this. I guess I'm wrong- as are all of the classes I took, the demonstrations I watched, every county and city health department manual, every HACCP manual, the USDA meat processing manual, any hospital sanitation manual I've read and all the others.

But in reviewing my previous posts on many topics; more than 80% of the things I've posted here you've objected to. Therefore, you're the king and I'm the nobody. I give up.

PS:
Some molds are harmless to us (as those on fromages bleus), some molds are a mere irritant and some are very dangerous to our health.

When you work Skq914, be sure to wear disposable clothing (or bag the clothes and take them straight to the laundry). Wear an appropriate cartridge respirator and eye protection in the form of tight sealing goggles. Cover your ears. Tarp the area with well sealed plastic sheeting, turn off fans and other air moving sources (even pilot lights of water heaters) If possible, create negative pressure sending air to outside.

Overkill? Maybe. Safe? Hopefully.

 

[Snoonyb]

"But in reviewing my previous posts on many topics; more than 80% of the things I've posted here you've objected to. Therefore, you're the king and I'm the nobody. I give up."

HMMMM, an interesting statistic, but one that I, would never, not only maintain, let alone publish, because, after all, exactly what is the value, that a statistic, like that, actually contribute, to the discussion, or for that matter, the site, itself.