Originally Posted by Andy M.
It wipes off easily with windex. Mold would be a powdery black. This is a greasy black that will smear and can be tracked to other areas. Besides, it appears suddenly.
The space between the floorboards looks much worse than it is.
Well Mr. Watson we're moving forward.
Mold would not necessary be powdery.
Is it actually greasy or just moist?
How long after floor cleaning does it appear?
It wipes off so it's on top of the finish.
It's not percolating through the wood so it's something placed on top.
Does it wipe off with simple water or is a solvent like windex needed?
Don't underestimate the size of the seam between your floorboards. It's gigantic to some of the things that live it this world.
And that it appears suddenly is no reason to discount some microbe.
We've got some weird orange mold at work that appears instantly when the plywood gets wet.
I think it's the glue.
For some reason I have in my head that you damp mop the area.
Some mysterious spores are spread in the process and where droplets of moisture are left the spooky black things grow.
They could be culled from those seams that appear insignificant.
I may be totally off base and I wish you well with Casper.
Keep us informed with what you find out.