Plastic and craft paper are not recommended for insulating your attic as they can create a second vapor barrier that traps moisture and causes condensation and mold. The right way to install a vapor barrier is to first remove the existing insulation and then install the barrier. After that, you can install a new layer of insulation over the barrier to completely seal your attic. It's important to remember that attic ventilation should not be obstructed when adding any type of insulation.
Otherwise, humidity-related problems could arise. Vapor barriers are especially important in humid and hot climates, as they provide a shield between exterior walls and insulation. This prevents moisture from entering and keeps insulation dry in cold climates. If you live in an area with cold winters, you'll need to install a vapor barrier before insulating your attic.
Low permeability vapor barriers are more effective at protecting attic insulation in colder climates. An alternative to plastic or craft paper is 8-inch uncoated fiberglass blocks, called attic blankets. Make sure your children place them perpendicular to the elements of the structure and keep them as close together as possible. Additionally, if your roof is porous at different points due to lighting installations or other appliances, you'll need to install a vapor barrier before insulating your attic.
Installing a vapor barrier in your attic can help protect those forgotten corners of your home from ruin. While not always necessary, it may be necessary if you live in a climate with colder winters. The cost and effectiveness of insulation vary depending on the type of fiberglass insulation you choose. An insulating vapor barrier can help keep your home warm and comfortable during the winter months.