[Wolverine7123]

Under carpet

 

[mikegp]

Looks pretty standard. Little sloppy, but nothing terrible. Tack strip, partially doubled, and foam pad. What's your concern?

 

[Wolverine7123]

Black spots on wood. I've found other mold in the apartment

 

[carpdad]

I don't see mold. Looks like nail strips on concrete and some moisture rust on the nails but no damage to the wood. I would think poor insulation and condensation. If you are certain about the mold, you have to find out where the moisture is coming from. Mold needs constant wetting. High humidity is not the problem.