Basement Wall Insulation Vapor Barrier
In any case the vapor barrier must point to the warm side.
Basement wall insulation vapor barrier. 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. The vapor barrier is sealed to the concrete wall at the bottom with some sort of seal and nailed directly to the concrete. Polyurethane sheeting is a typical vapor barrier that contractors use to prevent moisture from penetrating the walls of a basement. The material is stapled to the frame of a basement wall before it is finished with plaster or drywall.
The construction of the wall for instance is vital to the use of a vapor barrier. 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. Of foam against the wall this should not be a problem in your climate. The best option for insulating a basement is to use spray foam insulation.
Also be sure to use treated lumber for the bottom plate on the wall framing. This will give you two vapor barriers one before and one after the stud wall framing. This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses. Basement insulation vapor barriers the trick with basement insulation jobs is in understanding where water vapor is being stored and where it s moving to.
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. Not every wall does. The foam layer should be continuous and sealed at joints to keep indoor air away from the concrete. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. When the mold grows it will spread to everything around it studs drywall etc. Concrete is like a huge sponge which holds water and water vapor for years and years. A vapor barrier is also helpful to keeping a basement insulated and warm.
But if you use. With fiber insulation and a vapor barrier moisture can get trapped in the insulation leading to moldy insulation and decay in the wood framing. It provides the best coverage and r value and and functions as a moisture barrier in and of itself.