Plastic Vapor Barrier Bathroom Wall

They are required beneath your.

Plastic vapor barrier bathroom wall.

Install vapor barriers after the bathroom s plumbing electrical and insulation are complete. Use special sealing tape to join sheets if polyethylene sheets are being used. 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 type of insulation needs a vapor barrier.

Plastic specifically 6 mil polyethylene plastic is. Moisture barriers stop that water or vapor from getting any farther and potentially rotting your studs the drywall or greenboard installed behind the enclosure. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Do not install a vapor barrier over an existing plastic sheeting this will promote condensation.

But if it does the barrier should face inside in northern heating climates and outside in humid southern climates. Complete air blockage is essential to provide a satisfactory moisture barrier and will also maximize the wall s energy efficiency. Illustration by ian worpole. Vapor barriers sheets of plastic or kraft paper keep water vapor out of the wall cavity so the insulation stays dry.

Holes in the vapor barrier that allow humid air through may allow a lot more water vapor into an assembly than the vapor barrier is stopping. Without a vapor barrier in place condensation inside the walls could ruin the insulation and promote the growth of harmful mold and bacteria. A vapor barrier reduces the movement of water vapor by diffusion. It s also a relatively easy option for diyers.

Seal all wall cracks and holes in the wall being vapor proofed to block air gaps. Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating. Use a minimal amount of staples to secure the vapor barrier to the walls studs. Not every wall does.

When a vapor barrier is on the side of a wall where the dry air is i e outside in winter or inside in summer moisture problems can occur. Liquid barriers may also be used to prevent moisture from getting into the walls.