Question: Can You Put Plastic Over Insulation In Attic?

Do you need a vapor barrier for attic insulation?

If you insulate the attic floor, it is also important to have a vapor barrier in place, to prevent warm, moist air from rising into the chilled attic from the living space below.

The moisture will condense on the wood and insulation, reducing the insulation R-value and encouraging the growth of mold and mildew..

Can you leave fiberglass insulation exposed?

“Fiberglass insulation should never be left exposed in an occupied area, according to the American Lung Association,” says ALA’s Godfrey. “Exposed fiberglass insulation, once in the air, does cause respiratory reactions, such as dry, scratchy throat and coughing, as well as acting as a skin and eye irritant.

How can I cover insulation without drywall?

It will look really good and you’ll be able to install insulation without too much trouble either. This option can create a wall just as effectively as you would be able to when using drywall….Wood Planks.Plastic Panels.Plywood.Veneer Plaster.Pegboard.Lath and Plaster.Wahoo Walls.Textured Wall Panels.More items…

Does vapor barrier go over insulation?

Fiberglass insulation must stay dry to be effective. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. … In any case, the vapor barrier must point to the warm side.

What type of insulation can be left exposed?

Batts: Generally made of fiberglass, insulation batts and rolls are available either with face coverings or without. Brown Kraft paper is a common facing. Fire-retardant foil sometimes is used to cover batts that will be left exposed in unfinished spaces, such as a garage or basement.

How do you install attic insulation over existing?

As described above, lay unfaced fiberglass or mineral insulation over the existing insulation. Just remember to run it perpendicular to the joists. You can also top off existing insulation with loose fill fiberglass or cellulose, but fiberglass or mineral wool batts are easier and neater to install.

Should you cover insulation with plastic?

Condensation occurs whenever warm air meets cold air. … Without a vapor barrier in place, condensation inside the walls could ruin the insulation and promote the growth of harmful mold and bacteria. Plastic, specifically 6-mil polyethylene plastic, is the most commonly used vapor barrier.

Can you put a plastic vapor barrier over faced insulation?

Some builders choose to attach a separate vapor barrier even with faced insulation, however. It doesn’t hurt anything. Another option is to hang sheets of rigid foam insulation board over the insulated stud cavities. Run the foam, unbroken, from ceiling to floor.

Can I use unfaced insulation in attic?

You can use either faced or unfaced batting for this installation. When using insulation that has either paper or plastic facing, that moisture barrier faces outward, toward the attic space. Even if the attic space is unheated, it typically is warmer than the outside air in winter.

Do vapor barriers cause mold?

The Problem With Vapor Barriers This can lead to significant moisture problems and mold; problems occur when walls get wet during construction or more often throughout the home’s life. These wetting cycles can be from air flow, window leaks, pressure imbalances, and a host of lifestyle issues.

Should 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.

Can I put new vapor barrier over old?

Our best practices are that the old vapor barrier is left in place and the new one is placed over it. The old barrier even if it does not cover the entire crawl space serves to provide some additional moisture blocking and also help protect your new vapor barrier from any rocks or debris on your crawl space floor.

Can I put plywood over insulation in attic?

An attic can be floored with 1/2″ CDX plywood, if it is being used only for storage. However, the same can’t be said if you are planning on using the space as a living space. In that case, you will need to use 3/4″ thick plywood. … The building code allows for the use of OSB in place of plywood for subflooring.

How long does insulation last in the attic?

20 to 30 yearsThe typical lifespan is 20 to 30 years, with degradation beginning as early as 15 years after installation. As with other types of insulation, severe weather or outside interference can reduce the lifespan. Note: cellulose is often used as supplementary insulation.

Can you add insulation on top of existing insulation?

According to ENERGY STAR®, you can put new insulation over old insulation, “unless it is wet. … “Faced” insulation should not be placed on top of existing insulation in the attic. Any new roll or batt insulation installed over existing insulation in the attic needs to be without a vapor retarder (face).

Can you use 4 mil plastic for vapor barrier?

Barricade’s 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.

Can you double up 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.

How can I cover exposed insulation in my attic?

Suggestions for covering exposed insulation include the following:Seal the insulation by stapling a polymembrane sheet over it.Install paneling or sheetrock over insulation located in the wall.Install plywood flooring over insulation located in the floor.More items…

Can you cover fiberglass insulation with plastic?

Fiberglass insulation will not degrade unless exposed to water. The fiber could become airborne if a vent is blowing on it or it is disturbed in some way. It can be covered with a plastic vapor barrier to protect your home air quality.

Where should attic vapor barrier be placed?

The vapor barrier is always installed facing the heated side of the wall or ceiling, because that’s where the moisture is coming from.

Why is there moisture behind my insulation?

Condensation. Condensation occurs when the temperature of a surface falls below the dew point. … If the sheathing is below the dew point, determined by humidity levels and air temperature, condensation occurs on the inside of the sheathing, putting the sheathing, studs and insulation all at risk.