How to install vapor barrier in shower

A vapor barrier can be applied or installed over the tile substrate using a liquid or sheet membrane.

There is a clear advantage of using a liquid membrane, it is relatively easy to apply over the tile substrate, along with the use of a fiber mesh tape, you can secure joints and changes of plane. A sheet membrane has just as much of an advantage for ease of installation, but you gain the further benefit of continuity of thickness.

I have installed a 6 mil vapor barrier/retardant on two of the three walls where there's insulation in the wall cavities.

The seams and joints still need to be covered with a fiber mesh tape but you will be left with a sturdy surface.

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.

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”.

If moisture reaches your vapor barrier behind the tile substrate it should have the opportunity to evaporate, this process is hindered when

how to install vapor barrier behind shower wall

how to install a vapour barrier