The industry standard as well as most local building codes do not encourage the use of a vapor barrier behind and over the tile substrate.
Vapor barrier shower wall tile.
I recently noticed some wet drywall at the base of the shower on the outside corners of the enclosure.
Membranes like this also help support the drywall so it in turn can support the weight of the tile on the shower walls.
This is ideal for homeowners who are replacing tile and are unsure whether or not there s a proper vapor barrier behind the existing drywall.
Tile is laid onto the cement board with thinset mortar or mastic.
Also tile is heavy so put down blankets to protect the floors and tub from being damaged by falling.
In a shower situation you recognize it as steam.
In the case of water vapor you will want to consider installing a vapor barrier.
The materials that are most commonly used today for the installation of shower walls all either completely deter moisture penetration or encourage it to pass through a poor understanding of both could leave you with what is called a moisture sandwich.
Begin by removing the old tile or the fiberglass shower wall.
This is a dusty job so use plastic to cover your doorways wear a respirator that s rated for dust cover the floor with a drop cloth and make sure there s plenty of ventilation.
The vapor barrier will is only planned to be installed on the one wall of the shower that is an exterior wall of the home.
Steam stays in a gas form until it cools down or hits a barrier such as a shower door tile ceiling or a mirror.
In this highly convenient inexpensive and popular application a moisture barrier of 4 or 6 mil thick plastic is installed directly over the wall studs.
Screws secure the cement board to the wall studs.
Waterproofing a shower stops water in liquid form and vapor barriers stop water in gas steam form.
Examples of different wall coating products and their perm ratings.
My house is on a concrete slab and the shower was constructed with a mortar bed smooth river rock was used for the shower floor and cement board with a vapor barrier was used on the walls.
Basically any material rated at less than 1 perm is considered a vapor barrier retarder.
Water vapor is water in a gas form.
These products are simply painted on walls and floors on top of drywall or cement board instead of putting up a plastic vapor barrier behind the drywall.
References north american tile.