Do you need to put plastic over insulation?

Do you need to put plastic over insulation?

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.

Do you need a vapor barrier with faced insulation?

Since vapor barriers are only additional protection and not required to finish faced insulation, they are not always necessary. In fact, in some parts of the United States, it is better to not add vapor barriers as they can do more damage than good to your insulation.

Is a vapor barrier really necessary?

The short answer is: if your wall doesn’t have a vapor retarder, there is no need to worry. Builders worry way too much about vapor diffusion and vapor retarders. It’s actually very rare for a building to have a problem caused by vapor diffusion.

Should you put plastic over insulation on walls?

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.

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.

What is the best vapor barrier?

The Top 5 Underlayments for Vapor Barriers

• 8 Mil White/Black Dura-Skrim® Reinforced Plastic Sheeting.
• 12 Mil White/Black Dura-Skrim® Reinforced Plastic Sheeting.
• 20 Mil Dura Skrim® Reinforced Plastic Sheeting.
• VaporBlock® Vapor Barrier.
• PRO Crawl Barrier.
• Vapor Barrier Tape.

Can you 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.

Where do you put vapor barrier in walls?

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.

Do I need a vapor barrier with Tyvek?

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.