By the way you need a thermal insulation on top of that too.
Vapor barrier for basement concrete walls.
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.
Making basements appropriate places to live is more complicated than you might assume.
It s advised to run a vapor barrier just to make sure you don t get any moisture issues after finishing.
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.
Because of this you ve likely asked yourself.
1 on the interior wall between the heated and unheated portion of the basement i would not use with a vapor barrier.
Unlike cellars basements need to be dry comfortable environments that effectively keep out any possible contaminants.
The main concerns are condensation and drying potential.
Below grade walls and floor slabs transmit ground moisture through concrete walls or slabs.
Not to be confused with a vapor barrier which is placed on the warm side of the wall just in front of the insulation and behind the drywall a moisture barrier goes against the basement wall.
Should i install a vapor barrier in my basement.
Most jurisdictions require a 4 mil plastic sheet vapor barrier for basement walls against concrete.
That is if the studs are going to touch the concrete wall.
When the mold grows it will spread to.
The vapor barrier is sealed to the concrete wall at the bottom with some sort of seal and nailed directly to the concrete.
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.
Also be sure to use treated lumber for the bottom plate on the wall framing.
Very hot and humid climates may benefit from an exterior vapor barrier that keeps outside humidity from penetrating into walls.