Can you put a plastic vapor barrier over faced insulation?

No, you should not do this. As mentioned above, faced insulation that has a vapor barrier can easily trap moisture. If you put another faced insulation on top of face insulation, a significant amount of moisture can form inside your insulation and in your walls to damage them.
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Does vapor barrier go over kraft faced insulation?

The vapor retarder shall be installed on the warm-in-winter side of the thermal insulation." A lot of people call this a "vapor barrier" requirement, and believe polyethylene is required by the code, but kraft facing on batt insulation (which has a permeance of about 0.4) meets this code requirement all by itself.
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Does faced insulation need to be covered?

To satisfy building codes, most faced insulation must be covered with half-inch-thick wallboard or other code-approved material to reduce the chances of its igniting during a fire. There is a type of faced insulation approved for exposed installations.
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Do you need vapor barrier over insulation?

After the insulation is in place you will want to add a vapor retarder, sometimes called a vapor barrier, if you need one. Not every wall does. A vapor retarder is a material used to prevent water vapor from diffusing into the wall, ceiling or floor during the cold winter.
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Is it OK to put plastic over insulation?

Install the plastic sheeting only after the insulation, wiring and plumbing have been completed. Stretch the plastic sheet tightly across the top of the wall and staple it to the studs and plates with a hammer-tacker, a tool designed to install staples quickly and efficiently.
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Vapor Barriers: Need one or not?



Is it OK to cover insulation with plastic?

Plastic isn't recommended in this situation because it would create a second vapor barrier that can trap moisture and result in condensation and mold. Craft paper would have the same problem, this is what is most likely on the other side of the insulation for the vapor barrier you want.
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Do vapor barriers cause mold?

One of the more common problems with crawl spaces that do not have a crawl space vapor barrier system is that they create high moisture levels, which may result in mold growth – as dampness creates the ideal environment for mold growth.
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What is the difference between vapor barrier and moisture barrier?

Moisture barriers function to help in preventing water from entering inside of the wall cavity. On the other hand, vapor barriers basically prevent water vapor from the interior of the house to filter through the wall and condense on the warm side of the insulation.
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Can you use 4 mil plastic for vapor barrier?

OVERVIEW. Our 4-mil plastic sheeting is a multipurpose film perfect for a wide variety of construction or DIY projects. This medium-duty plastic sheeting is commonly used as a vapor barrier in between insulation and drywall, used as a drop cloth or a temporary cover for equipment and supplies.
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Does paper faced insulation need a vapor barrier?

In most climates, it needs a vapor barrier. Some builders rely on batts with attached kraft-paper facing to do that job, but Tom recommends unfaced batts, covered in plastic with all the seams taped shut.
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Can you leave faced insulation exposed?

Never leave faced insulation exposed. The facings on kraft-and foil-faced insulation will burn and must be installed in substantial contact with an approved ceiling wall or floor construction material.
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Do you put plastic over insulation before drywall?

Without poly beneath the drywall, water vapor hits the drywall and diffuses through to the drier (in summer) indoor air. By installing a sheet of poly there, you cut off that drying mechanism and water that finds its way into walls can stay there longer and do more damage.
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Can you put unfaced insulation over faced insulation?

No, faced insulation should not be added over existing insulation since the vapor retarder on top of or between layers of insulation can trap moisture. Let Accurate Insulation handle your home insulation project from start to finish.
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Is faced insulation better than Unfaced?

The Difference Between Faced And Unfaced Insulation

Faced just means that kraft paper is attached to the insulation itself. The paper helps improve the sturdiness of the insulation so it doesn't fall down as much. Unfaced insulation is just as good as faced, but it doesn't have that paper attached to it.
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Should I use faced insulation in my attic?

Attic Floor Insulation

Unfinished or uninsulated attics need a layer of protection to keep hot or cold air from migrating to the rest of your home. If you install batting between your attic floor joists, the material should be faced.
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Do I need a moisture barrier and vapor barrier?

Vapor barriers are necessary for crawl spaces. A moisture barrier is the minimum amount of protection you should have in your crawl space. Most people will forget about protecting their crawl spaces, and when they do, serious problems arise.
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Can I use house wrap as a vapor barrier?

For example, House wrap by itself is not an air barrier, it is a vapor barrier. However, IF installed properly, which is rare, with taped seams, bottom, top edges, and no tears, it acts as an air barrier. So primarily it acts as a vapor barrier, but installed properly can do both; vapor barrier and air barrier.
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What side of wall does vapor barrier go?

In order to prevent condensation from forming, a vapor barrier should be placed on the warm side of your insulation to stop warm, moist air from condensing on a cold surface inside your wall. In cold climates like Canada, for most of the year the vapor barrier should be on the inside of the insulation.
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Why are vapor barriers bad?

Vapor barriers are supposed to stop vapor diffusion through roofs, walls, and floors. But they can also can trap moisture, causing rot and mold. Where moisture comes from: Water vapor can be forced into wall assemblies from the warm side of the house.
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Can you put drywall over vapor barrier?

Typically, nothing is done. That puncture should be at a tight connection of drywall to stud, where airflow is impeded by the pressure of the screw holding the drywall and vapor barrier to the stud.
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What can I use to cover exposed insulation?

Common solutions for covering exposed insulation include:
  • Sealing the insulation by stapling a polymembrane sheet over it.
  • Installing paneling or sheetrock over wall insulation.
  • Installing plywood flooring over floor insulation.
  • Working with an insulation expert to ensure safe, code-compliant results.
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What can be used as a vapor barrier for insulation?

Vapor Blockers

Vapor barriers—sheets of plastic or kraft paper—keep water vapor out of the wall cavity, so the insulation stays dry. Not every type of insulation needs a vapor barrier. But if it does, the barrier should face inside in northern, heating climates, and outside in humid southern climates.
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When should I use Kraft faced insulation?

Kraft-Faced Insulation is best used on walls and floors to prohibit the growth of mold and mildew. While the paper lining does its best to prevent moisture from seeping into your home, we highly recommend that you use spray foam in your attic.
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