Tanking on Hardibacker

[davidmaddison]

Evening All,

Can you help me with the below?

I am building an ensuite in a spare room, and will be installing a square slimline shower tray (900 x 900), which will be surrounded by three walls and then the shower door.

On the walls I am installing 12mm Hardibacker board.
The floor is 18mm ply, and then 6mm Hardibacker on top.

1) Can you use a tanking system over Hardibacker? Would it be wise to tank the walls and under the shower tray?
2) Does the slimline tray (ABS Stone Resin) need to be bedded on sand and cement if the floor is level? Can I use silicone instead?
3) With the shower tray, should the Hardibacker on the walls come down to the tray, leaving a 6mm gap between board and tray, which will be sealed with silicone?

I know the tanking might be a belt and braces approach for a shower tray, however I just want to make sure my new kitchen ceiling is looked after in case there was ever a leak.

David

 

[lizzardtong]

hi mate.
about your shower
use wedi type board easier to work with and better properties and run them to the floor. then you have to tank just joints and screws. you can use them on the floor as well. then tank corners and jonts screws etc. to stick tray down to the floor i always use spf (single part flexible adhesive) and PU 40 sealant to stick side of tray to the wall. once its tiled i do use PU 40 to fill gap between tiles and tray once that dry i use normal "sealant" on top of it. hope that helps.
Matt

regarding to leaks. make sure that all pipes are off the floor. are coming from walls min 5 inch in mu case as i use 4 inch roller to tank bottom of the wall so the floor and 4 inch on the wall create "tray" then the only place where you can have a leak its trap under shower. and thats easy to locate in future.