If you have a framed wall that is adjacent to a concrete foundation wall where the vapor barrier is next to the drywall in front of the studs the fiberglass insulation gets wet and becomes a breeding ground for mold.
Vapor barrier concrete basement walls.
The builder insulated the upper 4ft of the basement wall with a pink batt style insulation which is held to the wall with a vapor barrier.
Below grade walls and floor slabs transmit ground moisture through concrete walls or slabs.
A vapor barrier against the concrete surface is generally recommended before wood framing or flooring materials are installed.
The vapor barrier is sealed to the concrete wall at the bottom with some sort of seal and nailed directly to the concrete.
The construction of the wall for instance is vital to the use of a vapor barrier.
Also be sure to use treated lumber for the bottom plate on the wall framing.
In winter the dew point of the interior air is typically about 50 f assuming an air temperature of 70 f and a relative humidity of 50.
The other option is to set the 2 4 wall framing in 4 from the masonry or concrete basement walls and use just the vapor barrier on the insulation facing toward the living space.
When the mold grows it will spread to.
The main concerns are condensation and drying potential.