Flooring and Carpeting/Black spots under carpet
I lately looked under my carpet and I found weird black spots under it. Here is some pictures under the carpet.
The spots are very sticky almost like tar.
This is a bit outside my area of expertise, however:
If they are tar, perhaps left over from some previous installation of something like perhaps a vinyl tile, they should clean up with an aromatic naphtha. If that is a wood floor underneath, you could also sand it down. If this is some sort of mold, treat with clorox bleach or hydrogen peroxide.
However you fix this, if you are going to put carpeting back down, I would at least seal the wood floors first so as to minimize any future issues with spills that could go through the carpet and pad.