anyone know about cement foundations

tonight i was in my brew room and noticed some black wet looking stuff on my cement wall, i have no idea what it is, its black, wet, and slimey and was hoping someone on this forum would know about this stuff.

the scratch marks are from me scratching it with a screwdriver

Might be mold/mildew. clean it with some bleach solution. You might have a weep spot somewhere in the wall there. Clean it up and see if you can find it, then seal up.

The moisture is either from above or through the wall. If through, make sure drain spouts are directed away from the house and that you have positive slope away from the house.

Don't seal the concrete. It will only trap moisture.

does it mean there a crack in my foundation? what is the slimey stuff?

That doesn't look like black mold but it could be. Can you take a pic of a larger area of wall to get some scale, it's hard to see what's going on. Concrete is very porous so water trapped behind it will weep though, so it doesn't mean you have a crack, but most all concrete cracks.

pickles said:

<s>but most</s> all concrete cracks.

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Fixed

BTW, is this concrete you refer to in a wall of a basement? You refer to "foundation" first and then "wall".

Looks like a combination of mold and algea slime.

Is this the vertical wall of teh basement or the actual floor slab?

Either way, looks like you have a drainage issue and I see a french drain in your future.

sorefingers23 said:

does it mean there a crack in my foundation? what is the slimey stuff?

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It may not be cracked. Moisture penetrates concrete and if there is a build up on one side, the hydrostatic pressure will have no problem getting through.

Hard to tell what the substance is. It's just what grew because of moisture. Solve the water source, solve the sluge

its algea, bleach the wall and find and fix drainage issue it will be fine

theres a better pic of the wall

the room is a cold room in the basement of my house

GilaMinumBeer said:

Looks like a combination of mold and algea slime.

Is this the vertical wall of teh basement or the actual floor slab?

Either way, looks like you have a drainage issue and I see a french drain in your future.

Click to expand...

its a vertical wall

Most likely the corner I a cold joint, so it has a purposefully placed crack where the two walls convene. You need to address your exterior drainage problems. Either the soil doesn't slope away from the house or a plugged gutter/downspout. Get rid of the water and the mold/algae will die. Then clean with a simple detergent solution, commercial biocides aren't (although readily available) recommended for mold remediation if not needed. They have some nasty stuff in them. The simple fact of removing the water will kill the mold. You can also use a bleach solution as mentioned earlier if you want piece of mind.