A common misconception is that all insulations require vapor barriers in all situations.
Vapor barrier for blown in insulation.
Vapor barriers keep the air moisture in your house from condensing in the insulated cavities.
If you live in a cold climate place the vapor barrier between the interior of your home and the insulation.
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.
This acts as a barrier to keep heated moist air from rising up into the attic during cold weather.
Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.
Research has shown that this is incorrect.
Not every wall does.
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 applied over the face of the insulation provide additional benefits in the fight against moisture.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
Usually composed of a thin film such as polyethylene vapor barriers are used to retard or prevent water vapor diffusion into a wall ceiling or floor during the cold winter.