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.

Should you cover insulation with plastic?

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.

What should I put between drywall and insulation?

Between the insulation and the sheetrock I staple 6 mil plastic; I was taught this a few years ago, and it seemed to make sense (as I recall, the reasoning was the the plastic forms a vapor barrier, which keeps interior moisture from getting “trapped” in the insulated walls).

Can I put plastic sheeting 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.

Should I put Poly 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.

Handyman Tips

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.

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.

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 you need to put drywall over insulation?

Drywall is considered a suitable construction material for interior walls, but its primary purpose is not to insulate. To make a significant difference in heat flow transfer, you must include insulation along with the drywall installation.

Can you put drywall over insulation?

To combat this problem, drywall is required to cover it. Drywall, which is actually a mineral called gypsum, resists fire. It also helps insulate and soundproof the room. The most common way to hang drywall over rigid foam insulation is to glue and screw it into place.

What can be used as a vapor barrier for insulation?

The most common materials for vapor barriers are plastic or aluminum sheeting. But depending on your situation, even paint can function as a vapor barrier! The permeability of a vapor barrier refers to how much water vapor can get through.

Is it OK to 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.

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.

Where should vapor barrier be installed?

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.

What do you put behind drywall?

Wires. Electrical cables are usually behind drywall, either running horizontally through holes in the studs or stapled vertically up the sides of studs. Outlet cables tend to be about 12 inches high. Light switches are around 48 inches high, so expect to see electric cables around that area.

Do I have to drywall over insulation in garage?

If you insulate it, your garage will be warmer - at least, after the door has been closed for a while - and you will lose less heat. It won't be super-warm, but it will help. You do not need 5/8" drywall for the garage walls. In the US, you need it between the garage and living space, but not on the exterior walls.

How do you cover foam insulation?

The most common approach is to apply a stucco-like “parged” finish with a surface-bonding cement. These finishes range from a thin paint-on coating to a thick acrylic-modified mortar applied over hardware cloth or metal or fiberglass lath. The thin paint-on coatings are easily chipped and prone to peeling.

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.

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 ...

Can you cover basement ceiling insulation with plastic?

Gypsum Sheetrock

This works for any insulation (for spray foam and foam board, plastic sheeting is not an acceptable solution as it is not a flame-resistant material).

Is vapor barrier required behind drywall?

No, you don't need a vapor retarder, Class I or otherwise. By the time you paint the drywall, though, you've brought it into the Class III vapor retarder range (between 1 and 10 perms), and even less water vapor will diffuse through. Seal the air leakage pathways.

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.

Is Tyvek 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.

What is the difference between a vapor barrier and a 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.

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.