I cant really get my head around the best thing to do to be honest. The situation is as follows. I have a shower enclosure which is slightly too small for the new shower tray. In a way this works to my advantage. I think. Why, because I stupidly bought 3mm wet wall panels. I didn't forsee the issues this would cause. (The panels not being thick enough to overlap the tray sufficiently)
Because I have very carefully chased out the plasterboard along two of the walls(the RHS and the rear wall) I can slot the tray onto these channels which then allows the 3mm panels to sit nicely on top of the tray and overlap it by around 5mm. However, this means that I have a gap between the tray and the wall on the LHS. I have bought an Aquaseal tanking kit to tank the walls and floor. I wanted to buy a lightweight tile backing board to place over the tray at the LHS. Therefore ensuring that the tray is overlapped. Much like a 8mm of tile adhesive, plus a 10mm wall tile would overlap the shower tray. I have prepped the channels with primer and will start coating the channels with the waterproofing. Obviously down to the floor.
I can't get my head around whether to...
1. Tank the walls down to and including the original floor.
Or
2. Tank down the walls and on to the OSB 3 board that will support the tray.
And on the LHS, do I tank down the original plastered wall to the original floor.
And the backer board that will only be fitted on the LHS... should I actually be tanking that instead instead of the plastered wall?
In my mind, in this application, should I be looking at the backer board as simply the bed of adhesive under the tiles. Just something to make up the gap?
If this is case, do i just buy some moisture resistant plasterboard and tank that. Although it wouldn't reach the OSB3 deck or the original floor.
Are you confused? 😆🤣
I am!
D