If I fit this tray do I need to put tile backing board on top of it? If i do add the backing board do I then need to use the tanking kit over the backing board and then tile it? It doesn't look like there is enough room between the tray and the top of the drain to have board and tiles.
The showerlay itself is covered with material that is perfect for tile-on, however please notice that it comes with integrated drainage which is 15 mm high, therefore you need to check your tile thickness. If your tiles are 10-14 mm thick, using tile backing board is not necessary, if your tiles are thinner then you may need to use tile backing boards to level the tiles with the drain's frame. Tiles must be flushed with the frame, otherwise water will not be drained.
In addition, if your tiles are thicker than 14 mm, we have alternative solution - Showerlay Invisible - it doesn't have any vertical frame at all so there's no restriction for your finish material height, however it have to be covered with your tiles, or other material (marble, stone) entirely.