Insulation For Basement Walls Vapor Barrier

Not so asphalt saturated kraft paper.

Insulation for basement walls vapor barrier.

Also on the graph is the permeance of polyethylene. The water vapor can come through the concrete from the soil or from indoor air that comes in contact with the concrete. In any case the vapor barrier must point to the warm side. If you live in a hot humid climate place the vapor barrier toward the outside of the wall cavity.

If you live in a cold climate place the vapor barrier between the interior of your home and the insulation. Of foam against the wall this should not be a problem in your climate. Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating. 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.

Joe says in the article plastic vapor barriers really are vapor barriers when things get wet. 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. Concrete is like a huge sponge which holds water and water vapor for years and years. Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall.

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. You should then use fiberglass insulation that has a vapor barrier between the studs with the vapor barrier facing in toward the living space. With fiber insulation and a vapor barrier moisture can get trapped in the insulation leading to moldy insulation and decay in the wood framing. And most walls with asphalt saturated kraft paper thank the building science gods for the difference.

When the mold grows it will spread to everything around it studs drywall etc. Not every wall does. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. As the wall dries the water vapor leaves the concrete and tries to penetrate the insulation and wall.

This will give you two vapor barriers one before and one after the stud wall framing. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. 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. The construction of the wall for instance is vital to the use of a vapor barrier.