Inspired by PlumberParts. This guide draws on "HOW TO INSTALL A SHOWER TRAY — Plumbing Tips" from PlumberParts, one of the UK’s most established plumbing channels with nearly 400,000 subscribers. Their walkthrough is particularly useful on checking floor level in both directions before committing to the waste position — the step most people skip and then regret.
1. Turn off the water supply
Before you start, isolate the water supply to the shower. If there is an existing shower in place, drain it down. If this is a new installation in a room without running water yet, you can skip this step, but know where your stopcock is and how to use it.
Remove any existing shower tray, tiles, or flooring in the area. The subfloor needs to be clean, firm, and free of any lumps or debris that might cause the new tray to rock.
2. Check the floor level
Use a spirit level to check the floor in both directions — front to back and side to side. The floor does not need to be perfectly flat, because the tray can be adjusted using the adjustable feet. But you need to know how much adjustment you will need before you start cutting the waste hole.
If the floor is very uneven, fill any significant dips with floor levelling compound and let it set fully before proceeding. A stable, flat base is much easier to work on.
3. Mark and cut the waste hole
Position the tray where it will sit and mark the position of the waste outlet on the floor. Then move the tray aside. Use a jigsaw or hole saw to cut a hole slightly larger than the waste trap body through the floorboards or screed.
Check underneath with a torch before cutting — look for joists, pipes, or cables. If the waste falls between joists, you are in luck. If a joist is in the way, you may need to notch or route around it, which changes the drain pipe routing.
4. Assemble and fit the shower waste
Most modern shower trays come with a waste and trap included. Assemble the waste body according to the manufacturer’s instructions — usually a threaded spigot that fits up through the tray from below, with a rubber seal and backnut to secure it.
Connect the trap and the drain pipe before the tray goes in. It is much easier to make these connections from below while you still have clear access. Once the tray is down, access is limited. Make sure the drain pipe has the correct fall toward the soil stack or gulley.
5. Position and level the tray
Lower the tray onto the adjustable feet and manoeuvre it into position. Check the waste outlet lines up with the hole in the floor. Then use a spirit level across the tray surface to check level in both directions.
Adjust each foot individually. Work methodically — bring one corner up or down, check, move to the next. The tray should be level side to side. It can have a very slight fall toward the waste from the far end, but most modern trays have the waste positioned so that level is correct.
6. Secure the tray and connect the waste
Once level, some trays are secured to the floor with silicone or adhesive pads. Follow the manufacturer’s guidance. Do not rigid-fix with screws unless the tray is specifically designed for that method — most acrylic and resin trays need to flex slightly.
Push the drain pipe connector firmly onto the trap outlet and check for a secure, watertight connection. Run a bead of plumber’s putty or silicone around the waste where it meets the tray surface, wipe away the excess, and leave to set.
7. Seal around the edges
Once the tray is in position and the waste is connected, run a bead of sanitary silicone sealant around the edge where the tray meets the wall. Smooth with a damp finger and leave for 24 hours before use.
Do not be tempted to rush this. Silicone that is not fully cured will not form a watertight seal. If the tray is going into a tiled enclosure, leave the tray-to-tile joint open until both the tiling and the tray are stable, then silicone last.
When to call a handyman
Call Richard if the floor is badly out of level, if the existing drainage is in an awkward position, or if the job involves moving the soil pipe. Shower tray installation is one of those jobs that looks simple but has a fair few ways to go wrong if the groundwork is not done carefully.
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The Sandwich Handyman can fit shower trays, connect wastes, and complete bathroom plumbing jobs throughout Sandwich and East Kent.
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