Is this black mold?? (flooring, vinyl, laminate, color)

[dahorton89]

I just moved into a new place, it's my first real day putting stuff away today and I noticed a patch of black... stuff... On my door to my patio.. after this discovery I found a lot pig dark patching around my main floor bathroom toilet...I'm including pics.. should I be worried?

[mmyk72]

If it's tile that the toilet is sitting on, then it could just be stain on the tile. Mold doesn't grow directly on tile (it's not a porous substrate).

If you want to test for mold cheap and easy, dab a Q-tip with Bleach and touch the black or colored spot. If the black color disappears after a few minutes, it 'could' be mold. Of course, it can also be stain that's being bleached out, so use some common sense here.

[dahorton89]

The toilet is sitting on laminate flooring and the stains look as though they are from beneath the flooring and are seeping through to the top. So there's no way to test that. The black stuff on my patio door however I can test. I just moved in yesterday and I'm renting. There also looks like there are remnants of cat litter around the floor of the bathroom near the toilet so I'm thinking there may have been a leak or flood at some point

[K'ledgeBldr]

That you confirmed vinyl flooring in the bath-
Yes, that is MOST likely mold/mildew. The toilet had to have been leaking for a while under the vinyl flooring, and the staining has made it through the substrate of the flooring material. It just can't penetrate the wear/decorative layer.

As for that "blob"- it would appear "something" landed there and then begin to run-down. Not knowing where this spot is in relation to the door itself (too close up); is there anything directly "above" that spot that would indicate a leak or some other..?

[eddiehaskell]

Looks like fecal matter.