Insulation For Basement Walls Vapor Barrier

This will give you two vapor barriers one before and one after the stud wall framing.

Insulation for basement walls vapor barrier.

As the wall dries the water vapor leaves the concrete and tries to penetrate the insulation and wall. 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 construction of the wall for instance is vital to the use of a vapor barrier. In any case the vapor barrier must point to the warm side.

The vapor barrier is sealed to the concrete wall at the bottom with some sort of seal and nailed directly to the concrete. Concrete is like a huge sponge which holds water and water vapor for years and years. With fiber insulation and a vapor barrier moisture can get trapped in the insulation leading to moldy insulation and decay in the wood framing. If you live in a cold climate place the vapor barrier between the interior of your home and the insulation.

Not so asphalt saturated kraft paper. Not every wall does. When the mold grows it will spread to everything around it studs drywall etc. If you live in a hot humid climate place the vapor barrier toward the outside of the wall cavity.

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 and. Joe says in the article plastic vapor barriers really are vapor barriers when things get wet. Also on the graph is the permeance of polyethylene. You should then use fiberglass insulation that has a vapor barrier between the studs with the vapor barrier facing in toward the living space.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. 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. Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.

And most walls with asphalt saturated kraft paper thank the building science gods for the difference. 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. 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. The water vapor can come through the concrete from the soil or from indoor air that comes in contact with the concrete.