Shower tray waste line:
Take the tray and position it up against the bare timber of the studs of the internal wall where it is to be fitted. Mark the full circle of the waste hole onto the existing floor. Take away the tray and mark outward a further 1 and a ½-inches (40 mm) in a square shape hole to be cut out. Using a circular saw or a jigsaw cut out this square hole.
This hole once cut will let you know straight away if you have any floor joist timber to move out of your way or whether it is good and clear. At this point if you are rejoining into an existing old shower or bath waste. See if there is movement of this waste pipe back towards the drain. If there is flex in it enough go ahead and assemble the shower waste trap into the tray. And then working back from the tray and the trap use suitable bends to bridge the gap onto the existing waste pipe.
However if you cannot easily get under the floor. Measure the exact centers off the tray to the traps position in the middle of the hole and transfer these measurements onto the floor by the hole. Place a PVC straight coupling or PVC to copper or to lead adaptor onto the waste pipe and using a rule inside this coupling socket measure to the inside of the coupling socket when you are holding the trap waste in exact position between your floor marks. Then take this measurement and cut the straight section of joining pipe you need or if you need to place a bend or bends for an offset place them now and take another straight pipe measurement into the trap. Then make a dry run and sight the trap to make sure it is exactly positioned in the center of the tray hole. Also you will need to make allowance for this trap to protrude upwards through the floor as required to neatly come in under the tray hole lip.
When you are happy with the dry run refit the tray and check the starting of the trap inner male thread insert section into its threaded female half. Remove the tray for the last time and mark the point where the PVC tube passes into the trap socket and the other socket at the waste pipe end. Also mark across down the length to give an indicator to work to when gluing to achieve the same angles.
Note: With a shower tray there must be fall in all directions the waste pipe takes all the way to its outfall at the drain or it will not drain properly.
Please note: Before final fitting of the easy clean waste trap for the shower you will have to make sure the tray is packed up to level all around and glue placed under the tray to hold it firmly as per the manufacturers recommendation.