How to Install a Shower Tray and Waste: Complete Guide

Installing a shower tray is one of the more achievable plumbing tasks for a confident DIYer — but it needs to be done correctly. A poorly installed tray will leak, and water damage behind walls or under floors is expensive to fix.

At Norbreck Bathroom & Tile Centre, we stock a full range of shower trays and wastes. This guide will walk you through the installation process step by step.

Step 1: Choose the Right Shower Tray

Before you install anything, make sure you have the right tray for your space and situation.

Tray types:
- Slimline trays (40–45mm high): Low profile, contemporary look. Require good access underneath for the waste — check your floor void depth before buying.
- Standard trays (90–120mm high): Easier to connect the waste as there's more clearance underneath. Better suited to solid floors.
- Wet room formers: Fully tiled over — the most premium option but requires professional waterproofing.

Tray materials:
- Acrylic: Lightweight, warm underfoot, affordable. Can flex slightly — ensure it's properly supported.
- Stone resin: Heavier, more rigid, premium feel. Less flex than acrylic. Our most popular choice.
- Ceramic/fireclay: Very durable but heavy. Less common in modern installations.

Size: Measure your shower enclosure carefully. Standard sizes range from 800x800mm to 1200x900mm. Allow for the thickness of any wall tiles when measuring.

Step 2: Check Your Floor and Waste Position

• Locate your existing waste outlet position. Ideally your new tray waste should align with the existing outlet — moving a soil pipe adds significant cost and complexity.
  - Check the floor is level. If not, you'll need to level it before installation — a tray that rocks will stress the waste connection and eventually leak.
  - Check the floor void depth (the space between the floor surface and the ceiling below). Slimline trays need at least 120mm of void for the waste trap. If you have a solid concrete floor, you may need to chase a channel for the waste pipe.
  - Ensure the waste pipe has adequate fall (gradient) to drain properly — a minimum of 1:40 fall is recommended.

   

  Step 3: Prepare the Area

  - Remove the old shower tray or bath if replacing.
  - Clean the floor thoroughly — remove any old adhesive, sealant, or debris.
  - If tiling the walls first (recommended), complete the wall tiling before fitting the tray. The tray should sit in front of the wall tiles, not behind them.
  - If the floor needs levelling, use a self-levelling compound and allow it to cure fully before proceeding.
  

  Step 4: Do a Dry Run

  Before applying any adhesive or sealant, place the tray in position and check:
  - It sits level in both directions (use a spirit level)
  - The waste outlet aligns with your waste pipe
  - There's adequate clearance to connect the waste trap underneath
  - The tray fits correctly within the enclosure with no gaps that can't be covered by the tray upstand or wall tiles

  Mark the position of the tray on the floor with a pencil before removing it.
  

  Step 5: Install the Waste

  - Fit the waste outlet to the tray before installation — it's much easier to do this with the tray on its side or upside down.
  - Apply plumber's putty or the supplied sealant around the waste flange.
  - Insert the waste from above, fit the rubber seal and backnut from below, and tighten firmly (but don't overtighten — you can crack the tray).
  - Attach the waste trap to the outlet. Most modern trays use a 90mm or 110mm trap — check your tray specification.

  Pro tip: Use a telescopic waste trap if you have limited void depth. These compress to as little as 50mm.
  

  Step 6: Bed the Tray

  Acrylic trays must be fully supported underneath to prevent flexing:
  - Apply a bed of rapid-set mortar or use a purpose-made shower tray leg kit (supplied with some trays).
  - For mortar bedding: mix to a firm consistency, spread evenly across the floor area, lower the tray into position, and press down firmly. Check level immediately and adjust before the mortar sets.
  - For leg kits: adjust the legs to level the tray, then lower into position.

  Stone resin trays are more rigid and can sometimes be installed without full mortar bedding — check the manufacturer's instructions.
  

  Step 7: Connect the Waste Pipe

  - Connect the trap outlet to your waste pipe using the appropriate connector.
  - Ensure the pipe has adequate fall towards the soil stack.
  - Hand-tighten all push-fit connections, then give a quarter turn with pliers — don't overtighten.
  - Check all connections are secure before sealing the tray.
  

  Step 8: Seal the Tray

  - Allow mortar bedding to cure for at least 24 hours before sealing.
  - Apply a bead of sanitary silicone sealant around the entire perimeter of the tray where it meets the wall tiles.
  - Use masking tape either side of the joint for a clean finish.
  - Smooth with a wet finger and remove the tape immediately.
  - Allow silicone to cure for 24 hours before using the shower.

  Pro tip: Never grout the joint between the tray and wall tiles. This joint will move slightly and grout will crack. Always use silicone.
  

  Step 9: Test Before You Tile or Enclose

  Before fitting the shower enclosure or any decorative panels:
  - Run water and check all waste connections for leaks
  - Check the tray drains freely with no pooling
  - Check the silicone seal is continuous with no gaps

  Fix any issues now — it's much harder once the enclosure is fitted.
  

  Need a Shower Tray or Waste?

  Browse our full range of shower trays and wastes online, or visit our Blackpool showroom where our team can advise on the right tray for your floor type and enclosure size.