Can you put plastic over insulation in attic?

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.

Should you put plastic over ceiling insulation?

Plastic vapor barriers should only be installed in vented attics in climates with more than 8,000 heating degree days. You can forego the plastic and use a vapor retarder (kraft-faced insulation or latex ceiling paint) in all other climates except hot-humid or hot-dry climates.

Is it OK to cover insulation in attic?

Ideally, the insulation is covered with kraft paper or house wrap before installing boards to ensure there are no gaps or openings left behind. Do not cover vents during this process. Sufficient ventilation is highly important in attic areas.

How can I cover exposed insulation in my attic?

Do you need a vapor barrier for attic insulation?

Fiberglass Insulation

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.

How to Beef Up Attic Insulation | This Old House

Can I put Poly over faced insulation?

More than likely, installing an additional layer of poly over kraft facing won't cause any problems — it's no more risky than if the wall had only unfaced batts and poly — and the risk of using poly on the interior is relatively low in a cold climate like New York's.

Can I use plastic sheeting as a vapor barrier?

Reinforced polyethylene plastic sheeting (poly) comes in a variety of thicknesses and strengths. A 6 mil thick poly is commonly used as a vapor barrier and offers short-term savings to the homeowner.

Why do you put plastic over insulation?

Cold Weather

The sheet of poly still cuts off drying to the indoors, but it keeps the water vapor in the humid indoor air away from the cold surfaces inside the wall. This is what building scientists proposed as the solution for walls that wouldn't hold paint back in the early days of insulation.

Is it safe to leave 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.

What can you put 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.

Can I cover my attic insulation with plywood?

Once the insulation is down, you can turn your attic into valuable storage space by covering the floor with plywood. It will also make the attic a safer place in which to walk.

Should exposed fiberglass insulation be covered?

In this case, even if you don't plan on completely finishing the basement, you should cover the exposed fiberglass insulation for safety reasons, including disturbing fiberglass insulation can send particles into the air that act as lung, eye, and skin irritants and children playing around exposed fiberglass insulation ...

How long can insulation be exposed?

Tests have shown that these laminated boards can withstand UV ray damage for a reasonably long time. That said, it's still advisable to cover any foam board insulation exposed to the Sun within 30-60 days at the most. On most projects, that's more than enough time to finish the exterior walls.

How do you cover insulation with plastic?

Apply a strip of insulation tape designed for vapor barrier use over any seam where the vapor barrier meets another surface such as the wood framing around a window or the rim of an electrical box. Run additional lengths over any seam where two pieces of plastic meet and seal any accidental holes or tears.

Do I need a plastic vapor barrier if I use 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.

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.

What type of insulation can be left exposed?

Do you have to cover batt insulation?

Because loose-fill or batt insulation on the attic floor and batts installed under floors are not exposed to significant air movement, they do not need to be covered on the exterior side.

How do you seal insulation?

Seal the gaps with caulk or expanding foam. When complete and dry, push the insulation back into place. Fill wiring and plumbing holes with expanding foam. Caulk around electrical junction boxes, and fill holes in box with caulk.

Where should vapor barrier be placed?

Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions: the inner surface in colder climates and the outer surface in hot, humid climates. In existing spaces, oil-based paints or vapor-barrier latex paints offer an effective moisture barrier.

Is vapor barrier necessary?

A vapour barrier is an important component in building construction. Its purpose is to help prevent water vapour from reaching building walls, ceilings, attics, crawlspaces or roofs, where it can condense and cause building materials to rot or grow mould.

How do you install a vapor barrier in an attic?

The best approach for a vented attic, in a cold climate, is installing a layer of drywall with a good coat of latex paint (the paint creates a semi-permeable vapor barrier). The insulation (fiberglass or cellulose) is then placed on top of the drywall with no vapor barrier above or below.

Can I use plastic instead of underlayment?

A: Avoid plastic sheeting on wood subfloors because it only serves to trap moisture and can lead to mold growth under the right conditions.

Is Tyvek considered a vapor barrier?

Is DuPont^™ Tyvek^® a vapor barrier? No, DuPont^™ Tyvek^® is not a vapor barrier. It is made with unique material science to keep air and bulk water out while allowing moisture vapor inside walls to escape.