Plastic Vapor Barrier Bathroom Wall

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.

Plastic vapor barrier bathroom wall.

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. Use a minimal amount of staples to secure the vapor barrier to the walls studs. Vapor barriers sheets of plastic or kraft paper keep water vapor out of the wall cavity so the insulation stays dry. Do not install a vapor barrier over an existing plastic sheeting this will promote condensation.

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. A vapor barrier reduces the movement of water vapor by diffusion. Install vapor barriers after the bathroom s plumbing electrical and insulation are complete. It s also a relatively easy option for diyers.

Not every wall does. Illustration by ian worpole. Run the height of the vapor barrier from the top all the way down into the shower pan make sure not cut too short before the water barrier. They are required beneath your.

Plastic specifically 6 mil polyethylene plastic is. Complete air blockage is essential to provide a satisfactory moisture barrier and will also maximize the wall s energy efficiency. Liquid barriers may also be used to prevent moisture from getting into the walls. Plastic sheeting is used because of its low level of water permeability.

Without a vapor barrier in place condensation inside the walls could ruin the insulation and promote the growth of harmful mold and bacteria. Seal all wall cracks and holes in the wall being vapor proofed to block air gaps. 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. Moisture barriers stop that water or vapor from getting any farther and potentially rotting your studs the drywall or greenboard installed behind the enclosure.