Research has shown that this is incorrect.
Vapor barrier for blown in insulation.
Not every wall does.
Cima does not recommend the use of vapor barriers with cellulose insulation except in circumstances of exceptionally high moisture levels such as an indoor pool facility or very cold climates.
Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
This acts as a barrier to keep heated moist air from rising up into the attic during cold weather.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
If you live in a cold climate place the vapor barrier between the interior of your home and the insulation.
Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case.
Vapor barriers applied over the face of the insulation provide additional benefits in the fight against moisture.
Settlement vapor barriers condensation r values voids this document assists building buyers owners or inspectors who need to diagnose identify or improve building insulation for new construction or retrofit and energy savings projects.
Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall.