Just ripped up the carpet and pad in the walkout basement of oir new house. It has very old vinyl type sheet flooring. I would assume it has asbestos but havent tested it.
I want to lay carpet and pad down. How does the old glued down sheet flooring effect the moisture that may rise up through the floor? Does it have a perm rating? There are some dark spots on the old floor, not sure if its mold or just from the adhesive. The old flooring is mostly intact, no bubbling etc...
Try hitting the stains with some bleach and water to see it it goes away.
Could be as simple as someone used the wrong glue and the color bled through.
The mold should have shown up on the back side of the old pad.
Ever check the moisture level in the room?