Should you put plastic over insulation?

Standard Installation Practices

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.

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.

Should I 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 plastic sheeting 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.

Can you 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.

Why you must have Vapor Barrier

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.

How do you cover exposed insulation?

What do you cover insulation with?

After the insulation is installed, it is necessary to cover it up with a vapor barrier so the glass fibers are not inhaled. The best vapor barrier to use is roll of plastic sheeting. This vapor barrier is easy to install and does an excellent job.

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.

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.

Can you put vapor barrier on both sides of insulation?

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.

Is it safe to leave insulation uncovered?

"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.

Can I cover my attic insulation with plastic?

Yes. Either wood or plastic would be a good idea. You are only going to be able to get narrow sheets of plywood through those holes, but just nail them up.

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.

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.

Should a house have a vapor barrier?

Vapor barriers protect against mold and rot inside structures by preventing condensation and moisture from building up and damaging building materials. If a home is being built in a very humid climate, a vapor barrier can be an essential source of protection from problems caused by excess moisture.

What insulation can be left exposed?

Do you need to cover fiberglass insulation?

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 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.

Does insulation need to breathe?

The insulation needs to “breathe” to do its job, so there must be a flow of air to the outside surfaces of the insulation. Paradoxically, insulation also needs to be sealed off on the inside surfaces. Walls or ceilings must be lined with a vapor barrier, a layer of a watertight material.

Can you cover basement ceiling insulation with plastic?

Some of the walls are covered in plastic; it would be pretty eassy to finish the walls and cover the ceiling, too. Thanks for the advice. 6 mil plastic is not recommended for basement walls and you should be placing 1/2" drywall over the insulation to create required 1 hour fire rating for the room.

Should you put plastic on exterior walls?

The standard installation of a plastic vapor barrier is between the studs and the drywall, but there are some exceptions to this. In exterior walls that are below-grade, like basement walls, plastic should not be used at all. Some applications require a different use of plastic vapor barriers.

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.

How important is a vapor barrier?

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.