I purchased your pure linear drain shower tray last year and I am only getting round to installing it now. I will have to bring the level up with backer board to get the tile up to the drain. What is best practice for applying the backer boards over the shower tray?
Tile backer boards need to have proper thickness. Distance from the shower tray surface to the top edge of the vertical frame of integrated drain is fixed, 15 mm, so is the maximum thickness for all your material that is going to be fitted on top of it. If your tiles are for example 8 mm, then 6 mm tile backer board should be used and 1 mm layer of tile adhesive.
Boards need to be cut diagonally, to match the angle of the premachined slopes on top of the shower tray. Backer boards can be stuck to the shower tray with tile adhesive, as the tray is covered with material that connects to tile adhesive well on both sides.
Hope that helps, if you have any questions I will be happy to assist.
David 020 7193 0953