Vapour Barrier In wet room ??, Extractor fan (Yes or No), Tanking.

[MissBuilding1975]

Hi All,

Currently renovating an old wetroom.

1. Removed everything back to brick. Currently, Have stud battened the walls, insulated the spacing and am now ready to apply the tile backer board, however, before I apply the tile backer board. Should I cover the insulation and battens with a Polythene Vapour Barrier then after apply the backer board?

2. I know tanking is crucial, I will be tanking the washers and (tape/tank) joint lines betweens boards, corners etc... though should I leave it there? or should I just go and tank the whole wetroom backer boards? Bearing in mind the backer board are the perfect surface for tiling anyway and are waterproof. (Backerboard below)

3. The wetroom has a small privacy window that is top opening, around 600mm wide x 700mm Height. So I can open this after using the wetroom? or is it advisable to install an extractor. What would you do?

I assume taking these steps would ensure a watertight wetroom not allowing moisture to pass-through the backer boards, even vapour barrier as mould cannot grow on plastic. Therefore no mould growth or penetration to the wooden battens.

Thank you in advance for your answers.

 

[noseall]

Mechanical extraction would be wise and essential If you are going through B'regs (Building Control etc).

Fit foil sandwich insulation, foam or mastic all large gaps then foil tape all joints. Use backer board as normal.

 

[23vc]

Definitely need an extractor. And you tank everywhere in the shower zone (walls and floor) surely, not just corners/joints. At least I always have.