Connecting a shower tray to a drain can be tricky, but it is possible with a little bit of work. First, you must ensure the floor underneath the shower tray is flat and level. This is important because the tray needs to be pushed back against the wall and it can only do this when the floor is perfectly flat.
If the floor is not level and straight, apply a self-leveling compound to the subfloor following the manufacturer’s instructions. Once this is done, run the compound up to a line you draw in step 1. This will help you create a 1/4-inch slope away from the walls and toward the shower drain pipe.
Then, apply a mortar bed to the subfloor over the lower flange of the shower drain pipe. This will provide a 1/4-inch slope that will prevent water from running into the walls of the shower. Once the mortar bed is dry, you can lay tile on top of it.
Once the floor is complete, you can move on to tiling up the rest of the bathroom. It is best to start tiling from the bottom up so you can fully seal the joint between the tray and the wall using silicone before fixing in place any tiles.
Next, you must fit the drain assembly into the shower drain opening so that it extends up above the bottom flange of the shower drain. This will enable the drain assembly to be positioned in the correct position as you are pushing the shower tray onto the shower base.
If you have chosen a compression drain (one that has a rubber gasket) to connect the shower drain to the pipe, remove the gasket before lowering the shower base on the shower drain. Then, lubricate the gasket with plumber’s soap and slide it inside of the drain body to connect the drain pipe. Once you have completed this, screw the drain strainer assembly into the drain body so that it extends above the liner, according to the manufacturer’s directions.
Then, use bolts to secure the drain fitting to the bottom flange beneath the liner. This will help keep the liner in place and will also ensure that the shower drain is fully supported and won’t collapse when you push the shower base onto it.
To make sure the drain assembly is completely seated, pour a small amount of water over it to check for leaks. If there are any, you will need to replace the drain assembly.
You will also need to fit a PVC wye fitting on the drain waste piping. This fitting is a Y-shaped piece that fits into horizontal drainage waste piping that’s close to the shower drain. Mark the section of waste piping you want to cut with a marker.
Then, prime both ends of the waste piping with purple PVC primer and then cement them together. This will help make them stronger and last longer. Afterward, you can run the piping up to the ceiling. Depending on your local plumbing code, you may need to fit a tee into the drain waste piping so that it can be connected to a new plumbing vent, or a mechanical type of vent.